Neurocognitive subgroups among newly diagnosed patients with schizophrenia spectrum or bipolar disorders: A hierarchical cluster analysis

Studies across schizophrenia (SZ) and bipolar disorder (BD) indicate common transdiagnostic neurocognitive subgroups. However, existing studies of patients with long-term illness precludes insight into whether impairments result from effects of chronic illness, medication or other factors. This study aimed to investigate whether neurocognitive subgroups across SZ and BD can be demonstrated during early illness stages. Data from overlapping neuropsychological tests were pooled from cohort studies of antipsychotic-naïve patients with first-episode SZ spectrum disorders (n = 150), recently diagnosed BD (n = 189) or healthy controls (HC) (n = 280). Hierarchical cluster analysis was conducted to examine if transdiagnostic subgroups could be identified based on the neurocognitive profile. Patterns of cognitive impairments and patient characteristics across subgroups were examined. Patients could be clustered into two, three and four subgroups, of which the three-cluster solution (with 83% accuracy) was selected for posthoc analyses. This solution revealed a subgroup covering 39% of patients (predominantly BD) who were cognitively relatively intact, a subgroup of 33% of patients (more equal distributions of SZ and BD) displaying selective deficits, particularly in working memory and processing speed, and a subgroup of 28% (mainly SZ) with global impairments. The globally impaired group exhibited lower estimated premorbid intelligence than the other subgroups. Globally impaired BD patients also showed more functional disability than cognitively relatively intact patients. No differences were observed across subgroups in symptoms or medications. Neurocognitive results can be understood by clustering analysis with similar clustering solutions occurring across diagnoses. The subgroups were not explained by clinical symptoms or medication, suggesting neurodevelopmental origins.

Trajectory of aberrant reward processing in patients with bipolar disorder - A longitudinal fMRI study

BACKGROUND

Bipolar disorder (BD), and especially the mania phenotype, is characterized by heightened reward responsivity and aberrant reward processing. In this longitudinal fMRI study, we investigated neuronal response during reward anticipation as the computed expected value (EV) and outcome evaluation as reward prediction error (RPE) in recently diagnosed patients with BD.

METHODS

Eighty remitted patients with BD and 60 healthy controls (HC) underwent fMRI during which they performed a card guessing task. Of these, 41 patients and 36 HC were re-scanned after 16 months. We compared reward-related neural activity between groups at baseline and longitudinally and assessed the impact of mood relapse.

RESULTS

Patients showed lower RPE signal in areas of the ventrolateral prefrontal cortex (vlPFC) than HC. In these regions, the HC showed decrease in RPE signal over time, which was absent in patients. Patients further exhibited decreased EV signal in the occipital cortex across baseline and follow-up. Patients who remained in remission showed normalization of the EV signal at follow-up. Baseline activity in the identified regions was not associated with subsequent relapse.

LIMITATIONS

Follow-up scans were only available in a relatively small sample. Medication status, follow-up time and BD illness duration prior to diagnosis varied.

CONCLUSIONS

Lower RPE signal in the vlPFC in patients with BD at baseline and its lack of normative reduction over time may represent a trait marker of dysfunctional reward-based learning or habituation. The increase in EV signal in the occipital cortex over time in patients who remained in remission may indicate normalization of reward anticipation activity.

Assessment of the neuronal underpinnings of cognitive impairment in bipolar disorder with a picture encoding paradigm and methodological lessons learnt

BACKGROUND

Mood disorders are often associated with persistent cognitive impairments. However, pro-cognitive treatments are essentially lacking. This is partially because of poor insight into the neurocircuitry abnormalities underlying these deficits and their change with illness progression.

AIMS

This functional magnetic resonance imaging (fMRI) study investigates the neuronal underpinnings of cognitive impairments and neuronal change after mood episodes in remitted patients with bipolar disorder (BD) using a hippocampus-based picture encoding paradigm.

METHODS

Remitted patients with BD (n=153) and healthy controls (n=52) were assessed with neuropsychological tests and underwent fMRI while performing a strategic picture encoding task. A subgroup of patients (n=43) were rescanned after 16 months. We conducted data-driven hierarchical cluster analysis of patients' neuropsychological data and compared encoding-related neuronal activity between the resulting neurocognitive subgroups. For patients with follow-up data, effects of mood episodes were assessed by comparing encoding-related neuronal activity change in BD patients with and without episode(s).

RESULTS

Two neurocognitive subgroups were revealed: 91 patients displayed cognitive impairments while 62 patients were cognitively normal. No neuronal activity differences were observed between neurocognitive subgroups within the dorsal cognitive control network or hippocampus. However, exploratory whole-brain analysis revealed lower activity within a small region of middle temporal gyrus in impaired patients, which significantly correlated with poorer neuropsychological performance. No changes were observed in encoding-related neuronal activity or picture recall accuracy with the occurrence of mood episode(s) during the follow-up period.

CONCLUSION

Memory encoding fMRI paradigms may not capture the neuronal underpinnings of cognitive impairment or effects of mood episodes.

Cognitive processing of infant stimuli in pregnant women with and without affective disorders and the association to postpartum depression

Pregnancy and childbirth are among the strongest risk factors for depression but the neurocognitive mechanisms underlying this enhanced risk are unknown. This study investigated emotional and non-emotional cognition in 57 pregnant women with or without an affective disorder during their third trimester, and the association between cognitive biases and subsequent postpartum depression (PPD). Of the pregnant women, 22 had a diagnosis of unipolar disorder (UD) and seven of bipolar disorder (BD) in full or partial remission, while 28 had no history of affective disorder. We included a control group of 29 healthy non-pregnant women. First, participants were interviewed, completed non-emotional and emotional cognitive tests and lastly filled out questionnaires. The participants were assessed two times after birth: at a home visit shortly after birth, and with a telephone interview to assess PPD in the first six months after birth. Healthy pregnant women rated infant cries less negatively than non-pregnant women, possibly reflecting preparation for motherhood. Pregnant women with UD exhibited a negative bias in ratings of infant cries, whereas pregnant women with BD showed a positive bias in ratings of infant happy faces and recognition of adult facial expressions. Across all pregnant women, more negative ratings of infant cries were associated with enhanced risk of PPD. Negatively biased perception of infant cries during pregnancy may thus signal vulnerability toward PPD.

A comparison of ICD-8 and ICD-10 diagnoses of affective disorder - a case register study from Denmark

The introduction of ICD-10 has changed the diagnostic borders of affective disorders in clinical psychiatry. The current study presents the diagnostic concordance between ICD-8 diagnoses given in 1993 and ICD-10 diagnoses given in 1994 to the same patients admitted in both years, according to the Danish register of psychiatric admissions. In total, 1,487 patients received an ICD-8 diagnosis of manicdepressive psychoses in 1993 and were re-admitted in 1994. The majority of patients (84.0%) with a manic-depressive diagnosis according to ICD-8 received a diagnosis of affective disorder according to ICD-10. Patients with a diagnosis of affective disorder according to ICD-10 had previously been diagnosed as manic-depressive (69.6%), psychogenic psychoses (8.7%). personality disorders (5.5%) or neurosis (3.2%) according to ICD-8. The ICD-10 concept of affective disorder thus appeared broader and more comprehensive compared with ICD-8.

2285Increased risk of out-of-hospital cardiac arrest associated with psychiatric disorders

Introduction

Patients with psychiatric disorders are at high risk of cardiovascular morbidity and mortality; yet, the risk of out-of-hospital cardiac arrest (OHCA) compared to the general population remains unknown.

Purpose

We investigated whether the presence and severity of different psychiatric disorders were associated with a higher risk of OHCA.

Methods

We conducted a case-control study matching all adult patients with OHCA of presumed cardiac cause between 2001 and 2014 with up to nine controls from the entire Danish population on age, sex and ischemic heart disease (IHD). Patients with psychiatric disorders were identified using in- and out-patient hospital diagnoses – both primary and secondary - before index date. We identified six mutually exclusive psychiatric disorders that were separately examined: personality disorders, anxiety, substance-related mental disorders, depression, bipolar disorder and schizophrenia. The risk of OHCA associated with the six psychiatric disorders was evaluated by conditional logistic regression adjusting for comorbidities, concomitant pharmacotherapy, socioeconomic status and marital status.

Results

We included 32,447 OHCA cases matched with 291,999 controls from the general population. Overall, the median age was 72 years, 67% were male and 29% had IHD prior to index date. All the six psychiatric disorders examined were more common among cases than controls; depression was the most common psychiatric disorders in both groups: 5.0% among cases and 2.8% among controls. Concurrently, all six psychiatric disorders were associated with significantly higher odds of OHCA: personality disorders (odds ratio (OR) 1.30 [95% confidence interval (CI) 1.06–1.60], anxiety OR 1.26 [95% CI 1.15–1.39], substance induced-mental disorders OR 2.36 [95% CI 2.17–2.57], depression OR 1.27 [95% CI 1.19–1.35], bipolar disorder OR 1.32 [95% CI 1.16–1.50] and schizophrenia OR 1.80 [95% CI 1.58–2.05] (Figure). The association persisted unaffected when we studied psychiatric patients neither exposed to antipsychotics nor to antidepressants. We observed a trend towards a stronger association when we stratified according to the severity of the psychiatric disorder (Figure). Severe disorders where classified as at least one hospitalization for the specific psychiatric illness as primary diagnosis during the five years prior to index date.

Conclusions

Common psychiatric disorders including personality disorders, anxiety, substance-related mental disorders, depression, bipolar disorder and schizophrenia are significantly associated with higher odds of OHCA. These findings provide a rationale for early cardiovascular risk factor screening and, potentially, management among psychiatric patients to identify patients at high risk of OHCA.

Acknowledgement/Funding

ESCAPE-NET project

P4135Patients with psychiatric disorders have reduced chances of receiving optimal post-arrest cardiovascular management

Introduction

Healthcare disparities between patients with and without a known psychiatric disorder have been documented worldwide. Whether these inequalities also apply to a life-threatening condition such as out-of-hospital cardiac arrest (OHCA) is unknown

Purpose

We aimed to investigate differences in selected in-hospital cardiovascular procedures following OHCA between patients with and without psychiatric disorders.

Methods

We identified adult patients with OHCA of presumed cardiac cause admitted to hospital following OHCA (2001–2015). Patients with psychiatric disorders were identified using hospital diagnoses or redeemed prescriptions for psychotropic drugs and studied both as a single group and separately (three subgroups: severe mental illness [SMI], minor psychiatric disorders, patients who redeemed psychotropic drugs). We calculated age- and gender-standardized incidence rates (SIRs), and relative incidence-rate-ratio (IRR), of cardiovascular procedures during admission post-OHCA in patients with and without psychiatric disorders. Differences in 30-day and 1-year survival were assessed by multiple logistic regression in the overall population and among 2-day survivors who received acute coronary angiography (CAG).

Results

We included 7,288 hospitalized OHCA-patients: 1505 (22.8%) had a psychiatric disorder. Compared with patients without psychiatric disorders, patients with psychiatric disorders had lower SIRs for acute CAG (≤1 days post-OHCA) (IRR 0.51 [95% confidence interval, CI, 0.45–0.57]) (Figure), subacute CAG (2–30 days post-OHCA) (IRR 0.40, [95% CI 0.30–0.52]) and ICD-implantation (IRR 0.67, [95% CI 0.48–0.97]). Lower rates of acute and subacute CAG were still present in subanalyses only including patients with initial shockable rhythm, among those with return of spontaneous circulation upon hospital-arrival and regardless of Charlson score and socioeconomic status. Notably, the difference in CAG-rates between the two groups increased in the recent years. Conversely, we did not detect differences in coronary revascularization (encompassing coronary artery bypass graft and percutaneous coronary intervention) among CAG-patients (IRR 1.11 [95% CI 0.94–1.30]) (Figure). Patients with psychiatric disorders showed lower survival following OHCA, even among 2-day survivors who received acute CAG: odds (OR) of 30-day survival 0.63 (95% CI, 0.48–0.83) and 1-year survival 0.61 (95% CI 0.46–0.81).

Conclusions

Patients with psychiatric disorders had half the probability of receiving acute and subacute CAG and lower chances of ICD-implantation compared to non-psychiatric patients, but, among CAG-patients, same probability of coronary revascularization. Moreover, their survival was lower irrespective of acute angiographic procedures. Our findings show disparities that demand urgent action considering the large burden of cardiovascular morbidity and mortality in patients with psychiatric disorders.

Acknowledgement/Funding

ESCAPE-NET

P2548Lithium use and risk of out-of-hospital cardiac arrest in patients with bipolar disorder: A nationwide nested case-control study

Background

Lithium is a mood stabilizer widely used in the treatment of bipolar disorder. Lithium has been linked to malignant proarrhythmic electrocardiographic changes such as QT-prolongation, atrioventricular and sinoatrial block. However, evidence regarding the risk of cardiac arrest with lithium use is lacking.

Purpose

We investigated the risk of out-of-hospital cardiac arrest associated with lithium use among patients with bipolar disorder.

Methods

All out-of-hospital cardiac arrest cases from 2001 through 2014 of presumed cardiac cause with a history of bipolar disorder were identified from the nationwide Danish Cardiac Arrest Registry. We conducted a nested case-control study by matching all cardiac arrest cases with bipolar disorder on age, sex and time since first diagnosis of bipolar disorder with four controls from the general population who also had a history of bipolar disorder. Conditional logistic regression adjusted for comorbidities and concomitant pharmacotherapy was used to determine the association between lithium monotherapy and risk of out-of-hospital cardiac arrest compared to mood stabilizing monotherapy with valproate, lamotrigine and quetiapine, respectively. Exposure was defined as redeemed prescriptions for only one of either lithium, valproate, lamotrigine or quetiapine up to two months before index.

Results

The study population consisted of 1,410 patients with bipolar disorder, comprising 282 out-of-hospital cardiac arrest cases each matched with 4 controls. The median age was 69 years, 47.2% were male and the median time from first diagnosis of bipolar disorder was 7.25 years. Among cases, 59 (20.9%) were in lithium monotherapy and among controls the number was 299 (26.5%). For monotherapy with other mood stabilizers we observed the following distributions: quetiapine 18 (6.4%) cases and 51 (4.5%) controls, valproate 12 (4.3%) cases and 51 (4.5%) controls, and lamotrigine 15 (5.3%) cases and 64 (5.7%) controls. Lithium was not associated with an increased risk of OHCA compared to other mood stabilizing drugs: Hazard ratio (HR) 0.64 [95% confidence interval (CI) 0.31–1.33] (reference quetiapine), HR 0.56 [95% CI 0.25–1.24] (reference valproate) and HR 0.53 [95% CI 0.25–1.10] (reference lamotrigine).

Figure 1

Conclusion

Among patients with bipolar disorder, lithium was not associated with an increased risk of cardiac arrest compared to other mood stabilizing drugs. Further studies focusing on the cardiovascular safety of mood stabilizing drugs are warranted.

The association between mixed symptoms, irritability and functioning measured using smartphones in bipolar disorder

OBJECTIVE

To (i) validate patient-evaluated mixed symptoms and irritability measured using smartphones against clinical evaluations; (ii) investigate associations between mixed symptoms and irritability with stress, quality of life and functioning, respectively, in patients with bipolar disorder.

METHODS

A total of 84 patients with bipolar disorder used a smartphone-based system for daily evaluation of mixed symptoms and irritability for nine months. Clinically evaluated symptoms, stress, quality of life and clinically rated functioning were collected multiple times during follow-up.

RESULTS

Patients presented mild affective symptoms. Patient-reported mixed symptoms and irritability correlated with clinical evaluations. In analyses including confounding factors there was a statistically significant association between both mixed symptoms and irritability and stress (P < 0.0001) and between irritability and both quality of life and functioning (P < 0.0001) respectively. There was no association between mixed mood and both quality of life and functioning.

CONCLUSION

Mixed symptoms and irritability can be validly self-reported using smartphones in patients with bipolar disorder. Mixed symptoms and irritability are associated with increased stress even during full or partial remission. Irritability is associated with decreased quality of life and functioning. The findings emphasize the clinical importance of identifying inter-episodic symptoms including irritability pointing towards smartphones as a valid tool.

Is aberrant affective cognition an endophenotype for affective disorders? - A monozygotic twin study

BACKGROUND

Identification of endophenotypes can improve prevention, detection and development of new treatments. We therefore investigated whether aberrant affective cognition constitutes an endophenotype for affective disorders by being present in monozygotic (MZ) twins with unipolar or bipolar disorder in partial remission (i.e. affected) and their unaffected co-twins (i.e. high-risk) relative to twins with no family history of affective disorder (i.e. low-risk).

METHODS

We conducted an assessor blind cross-sectional study from 2014 to 2017 of MZ twins using Danish population-based registers in recruitment. Twins attended one test session involving neurocognitive testing, clinical ratings and questionnaires. Main outcomes were attention to and recognition of emotional facial expressions, the memory of emotional self-referential words, emotion regulation and coping strategies.

RESULTS

Participants were 103 affected, 44 high-risk and 36 low-risk MZ twins. Groups were demographically well-balanced and showed comparable non-affective cognitive performance. We observed no aberrant affective cognition in affected and high-risk relative to low-risk twins. However, high-risk twins displayed attentional avoidance of emotional faces (ps ⩽ 0.009) and more use of task-oriented coping strategies (p = 0.01) compared with affected twins. In contrast did affected twins show more emotion-oriented coping than high- and low-risk twins (ps ⩽ 0.004).

CONCLUSIONS

Our findings provide no support of aberrant affective cognition as an endophenotype for affective disorders. High-risk twins' attentional avoidance of emotional faces and greater use of task-oriented coping strategies may reflect compensatory mechanisms.

A multisystem composite biomarker as a preliminary diagnostic test in bipolar disorder

OBJECTIVE

Diagnosis and management of bipolar disorder (BD) are limited by the absence of available laboratory tests. We aimed to combine data from different molecular levels and tissues into a composite diagnostic and state biomarker.

METHODS

Expression levels of 19 candidate genes in peripheral blood, plasma levels of BDNF, NT-3, IL-6 and IL-18, leukocyte counts, and urinary markers of oxidative damage to DNA and RNA were measured in 37 adult rapid-cycling patients with BD in different affective states during a 6- to 12-month period and in 40 age- and gender-matched healthy individuals in a longitudinal, repeated measures design comprising a total of 211 samples. A composite biomarker was constructed using data-driven variable selection.

RESULTS

The composite biomarker discriminated between patients with BD and healthy control individuals with an area under the receiver operating characteristic curve (AUC) of 0.83 and a sensitivity of 73% and specificity of 71% corresponding with a moderately accurate test. Discrimination between manic and depressive states had a moderate accuracy, with an AUC of 0.82 and a sensitivity of 92% and a specificity of 40%.

CONCLUSION

Combining individual biomarkers across tissues and molecular systems could be a promising avenue for research in biomarker models in BD.

Remitted affective disorders and high familial risk of affective disorders associate with aberrant intestinal microbiota

OBJECTIVE

Affective disorders seem associated with aberrant intestinal microbiota but whether this pattern also occurs in individuals at increased heritable risk is unknown. We investigated associations between gut microbiota profiles and affective disorders by comparing monozygotic (MZ) twins concordant (affected twins with unipolar or bipolar disorder in remission) and discordant to affective disorders (high-risk) with MZ twins without affective disorders (low-risk).

METHODS

Stool samples were collected from 128 MZ twins and the microbiome was profiled using 16S rDNA sequencing of the V3-V4 region.

RESULTS

Affected twins had a lower diversity and an absence of a specific operational taxonomical unit (OTU) in comparison with low-risk twins. The high-risk twins exhibited the same pattern although the lower diversity was only at a trend level. The OTU belonged to the family Christensenellaceae. The findings were not explained by lifestyle factors (smoking, alcohol consumption, body mass index, or psychotropic medication).

CONCLUSION

Affected twins in remission and high-risk twins presented aberrant gut microbiota with depletion of a specific OTU. If replicated, this reduced relative sequence absence may together with the globally altered microbiota composition act as a vulnerability marker by accentuating the effect of gene-environment interactions in individuals genetically disposed for an affective disorder.

New drug candidates for depression - a nationwide population-based study

OBJECTIVE

To investigate whether continued use of non-aspirin NSAID, low-dose aspirin, high-dose aspirin, statins, allopurinol and angiotensin agents decreases the rate of incident depression using Danish nationwide population-based registers.

METHODS

All persons in Denmark who purchased the exposure medications of interest between 1995 and 2015 and a random sample of 30% of the Danish population was included in the study. Two different outcome measures were included, (i) a diagnosis of depressive disorder at a psychiatric hospital as in-patient or out-patient and (ii) a combined measure of a diagnosis of depression or use of antidepressants.

RESULTS

A total of 1 576 253 subjects were exposed to one of the six drugs of interest during the exposure period from 2005 to 2015. Continued use of low-dose aspirin, statins, allopurinol and angiotensin agents was associated with a decreased rate of incident depression according to both outcome measures. Continued uses of non-aspirin NSAIDs as well as high-dose aspirin were associated with an increased rate of incident depression.

CONCLUSION

The findings support the potential of agents acting on inflammation and the stress response system in depression as well as the potential of population-based registers to systematically identify drugs with repurposing potential.

Neural correlates of improved recognition of happy faces after erythropoietin treatment in bipolar disorder

OBJECTIVE

Bipolar disorder is associated with impairments in social cognition including the recognition of happy faces. This is accompanied by imbalanced cortico-limbic response to emotional faces. We found that EPO improved the recognition of happy faces in patients with bipolar disorder. This randomized, controlled, longitudinal fMRI study explores the neuronal underpinnings of this effect.

METHOD

Forty-four patients with bipolar disorder in full or partial remission were randomized to eight weekly erythropoietin (EPO; 40 000 IU) or saline (NaCl 0.9%) infusions in a double-blind, parallel-group design. Participants underwent whole-brain fMRI at 3T, mood ratings and blood tests at baseline and week 14. During fMRI, participants viewed happy and fearful faces and performed a gender discrimination task.

RESULTS

Thirty-four patients had complete pre- and post-treatment fMRI data (EPO: N = 18, saline: N = 16). Erythropoietin vs. saline increased right superior frontal response to happy vs. fearful faces. This correlated with improved happiness recognition in the EPO group. Erythropoietin also enhanced gender discrimination accuracy for happy faces. These effects were not influenced by medication, mood, red blood cells or blood pressure.

CONCLUSIONS

Together with previous findings, the present observation suggests that increased dorsal prefrontal attention control is a common mechanism of EPO-associated improvements across several cognitive domains.

Effect of electroconvulsive therapy on neural response to affective pictures: A randomized, sham-controlled fMRI study

Electroconvulsive therapy (ECT) is the most effective treatment for severe depression but its neurocognitive mechanisms are unclear. This randomized, sham-controlled functional magnetic resonance imaging (fMRI) study explored the effects of a single ECT on neural response to affective pictures. Twenty-seven patients with major depressive disorder were randomized to a single active ECT (N = 15) or sham (N = 12) session in a double-blind, parallel-group design. On the following day, patients underwent fMRI during which they viewed pleasant, unpleasant and neutral pictures and performed a free recall test after the scan. Mood symptoms were assessed before ECT/sham and at the time of fMRI. Subsequently, all patients continued active ECT as usual. Mood symptoms were reassessed after six active ECT sessions. A single ECT vs. sham session reduced neural response to unpleasant vs. pleasant pictures in the medial prefrontal cortex, a region showing greater response in the more depressed patients. This effect occurred in the absence of between-group differences in picture recall, mood symptoms or concomitant medication. In conclusion, modulation of medial prefrontal hyper-activity during encoding of negative affective information may be a common mechanism of distinct biological depression treatments.

Assessing and addressing cognitive impairment in bipolar disorder: the International Society for Bipolar Disorders Targeting Cognition Task Force recommendations for clinicians

OBJECTIVES

Cognition is a new treatment target to aid functional recovery and enhance quality of life for patients with bipolar disorder. The International Society for Bipolar Disorders (ISBD) Targeting Cognition Task Force aimed to develop consensus-based clinical recommendations on whether, when and how to assess and address cognitive impairment.

METHODS

The task force, consisting of 19 international experts from nine countries, discussed the challenges and recommendations in a face-to-face meeting, telephone conference call and email exchanges. Consensus-based recommendations were achieved through these exchanges with no need for formal consensus methods.

RESULTS

The identified questions were: (I) Should cognitive screening assessments be routinely conducted in clinical settings? (II) What are the most feasible screening tools? (III) What are the implications if cognitive impairment is detected? (IV) What are the treatment perspectives? Key recommendations are that clinicians: (I) formally screen cognition in partially or fully remitted patients whenever possible, (II) use brief, easy-to-administer tools such as the Screen for Cognitive Impairment in Psychiatry and Cognitive Complaints in Bipolar Disorder Rating Assessment, and (III) evaluate the impact of medication and comorbidity, refer patients for comprehensive neuropsychological evaluation when clinically indicated, and encourage patients to build cognitive reserve. Regarding question (IV), there is limited evidence for current evidence-based treatments but intense research efforts are underway to identify new pharmacological and/or psychological cognition treatments.

CONCLUSIONS

This task force paper provides the first consensus-based recommendations for clinicians on whether, when, and how to assess and address cognition, which may aid patients' functional recovery and improve their quality of life.

Is negative self-referent bias an endophenotype for depression? An fMRI study of emotional self-referent words in twins at high vs. low risk of depression

BACKGROUND

Negative cognitive bias and aberrant neural processing of self-referent emotional words seem to be trait-marks of depression. However, it is unclear whether these neurocognitive changes are present in unaffected first-degree relatives and constitute an illness endophenotype.

METHODS

Fifty-three healthy, never-depressed monozygotic or dizygotic twins with a co-twin history of depression (high-risk group: n = 26) or no first-degree family history of depression (low-risk group: n = 27) underwent neurocognitive testing and functional magnetic imaging (fMRI) as part of a follow-up cohort study. Participants performed a self-referent emotional word categorisation task and free word recall task followed by a recognition task during fMRI. Participants also completed questionnaires assessing mood, personality traits and coping strategies.

RESULTS

High-risk and low-risk twins (age, mean ± SD: 40 ± 11) were well-balanced for demographic variables, mood, coping and neuroticism. High-risk twins showed lower accuracy during self-referent categorisation of emotional words independent of valence and more false recollections of negative words than low-risk twins during free recall. Functional MRI yielded no differences between high-risk and low-risk twins in retrieval-specific neural activity for positive or negative words or during the recognition of negative versus positive words within the hippocampus or prefrontal cortex.

CONCLUSIONS

The subtle display of negative recall bias is consistent with the hypothesis that self-referent negative memory bias is an endophenotype for depression. High-risk twins' lower categorisation accuracy adds to the evidence for valence-independent cognitive deficits in individuals at familial risk for depression.

Methodological recommendations for cognition trials in bipolar disorder by the International Society for Bipolar Disorders Targeting Cognition Task Force

OBJECTIVES

To aid the development of treatment for cognitive impairment in bipolar disorder, the International Society for Bipolar Disorders (ISBD) convened a task force to create a consensus-based guidance paper for the methodology and design of cognition trials in bipolar disorder.

METHODS

The task force was launched in September 2016, consisting of 18 international experts from nine countries. A series of methodological issues were identified based on literature review and expert opinion. The issues were discussed and expanded upon in an initial face-to-face meeting, telephone conference call and email exchanges. Based upon these exchanges, recommendations were achieved.

RESULTS

Key methodological challenges are: lack of consensus on how to screen for entry into cognitive treatment trials, define cognitive impairment, track efficacy, assess functional implications, and manage mood symptoms and concomitant medication. Task force recommendations are to: (i) enrich trials with objectively measured cognitively impaired patients; (ii) generally select a broad cognitive composite score as the primary outcome and a functional measure as a key secondary outcome; and (iii) include remitted or partly remitted patients. It is strongly encouraged that trials exclude patients with current substance or alcohol use disorders, neurological disease or unstable medical illness, and keep non-study medications stable. Additional methodological considerations include neuroimaging assessments, targeting of treatments to illness stage and using a multimodal approach.

CONCLUSIONS

This ISBD task force guidance paper provides the first consensus-based recommendations for cognition trials in bipolar disorder. Adherence to these recommendations will likely improve the sensitivity in detecting treatment efficacy in future trials and increase comparability between studies.

Continuation of lithium after a diagnosis of chronic kidney disease

OBJECTIVE

To investigate whether continued lithium or anticonvulsant treatment after a first diagnosis of chronic kidney disease (CKD) was associated with progression to irreversible end-stage kidney disease.

METHODS

Nationwide cohort study including all individuals in Denmark in a period from 1995 to 2012 with a diagnosis of CKD and (i) a history of lithium treatment (N = 754, among whom 238 patients had a diagnosis of bipolar disorder) or (ii) a history of anticonvulsant treatment (N = 5.004, among whom 199 patients had a diagnosis of bipolar disorder). End-stage CKD was defined as chronic dialysis or renal transplantation.

RESULTS

Continuing lithium (HR = 0.58 (95% CI: 0.37-0.90) and continuing anticonvulsants (HR = 0.53 (95% CI: 0.44-0.64) were associated with decreased rates of end-stage CKD. In the subcohorts of patients with a diagnosis of bipolar disorder, continuing lithium was associated with decreased end-stage CKD (HR = 0.40 (95% CI: 0.17-0.98), whereas continuing anticonvulsants was not (HR = 0.70 (95% CI: 0.21-2.37). There were no interactions of continuing lithium and anticonvulsants.

CONCLUSION

After an initial diagnosis of CKD, patients who are selected by their physicians to continue lithium treatment may not necessarily have an increased risk of developing end-stage CKD. Shifting to an anticonvulsant per se may not be associated with an advantage; however, this requires further investigation.

Differences in neural and cognitive response to emotional faces in middle-aged dizygotic twins at familial risk of depression

BACKGROUND

Negative bias and aberrant neural processing of emotional faces are trait-marks of depression but findings in healthy high-risk groups are conflicting.

METHODS

Healthy middle-aged dizygotic twins (N = 42) underwent functional magnetic resonance imaging (fMRI): 22 twins had a co-twin history of depression (high-risk) and 20 were without co-twin history of depression (low-risk). During fMRI, participants viewed fearful and happy faces while performing a gender discrimination task. After the scan, they were given a faces dot-probe task, a facial expression recognition task and questionnaires assessing mood, personality traits and coping.

RESULTS

Unexpectedly, high-risk twins showed reduced fear vigilance and lower recognition of fear and happiness relative to low-risk twins. During face processing in the scanner, high-risk twins displayed distinct negative functional coupling between the amygdala and ventral prefrontal cortex and pregenual anterior cingulate. This was accompanied by greater fear-specific fronto-temporal response and reduced fronto-occipital response to all emotional faces relative to baseline. The risk groups showed no differences in mood, subjective state or coping.

CONCLUSIONS

Less susceptibility to fearful faces and negative cortico-limbic coupling during emotional face processing may reflect neurocognitive compensatory mechanisms in middle-aged dizygotic twins who remain healthy despite their familial risk of depression.

The catechol-O-methyltransferase (COMT) Val158Met genotype modulates working memory-related dorsolateral prefrontal response and performance in bipolar disorder

OBJECTIVES

Cognitive dysfunction affects a substantial proportion of patients with bipolar disorder (BD), and genetic-imaging paradigms may aid in the elucidation of mechanisms implicated in this symptomatic domain. The Val allele of the functional Val158Met polymorphism of the catechol-O-methyltransferase (COMT) gene is associated with reduced prefrontal cortex dopamine and exaggerated working memory-related prefrontal activity. This functional magnetic resonance imaging (fMRI) study investigated for the first time whether the COMT Val158Met genotype modulates prefrontal activity during spatial working memory in BD.

METHODS

Sixty-four outpatients with BD in full or partial remission were stratified according to COMT Val158Met genotype (ValVal [n=13], ValMet [n=34], and MetMet [n=17]). The patients completed a spatial n-back working memory task during fMRI and the Cambridge Neuropsychological Test Automated Battery (CANTAB) Spatial Working Memory test outside the scanner.

RESULTS

During high working memory load (2-back vs 1-back), Val homozygotes displayed decreased activity relative to ValMet individuals, with Met homozygotes displaying intermediate levels of activity in the right dorsolateral prefrontal cortex (dlPFC) (P=.016). Exploratory whole-brain analysis revealed a bilateral decrease in working memory-related dlPFC activity in the ValVal group vs the ValMet group which was not associated with differences in working memory performance during fMRI. Outside the MRI scanner, Val carriers performed worse in the CANTAB Spatial Working Memory task than Met homozygotes (P≤.006), with deficits being most pronounced in Val homozygotes.

CONCLUSIONS

The association between Val allelic load, dlPFC activity and WM impairment points to a putative role of aberrant PFC dopamine tonus in the cognitive impairments in BD.

Evidence for clinical progression of unipolar and bipolar disorders

OBJECTIVE

It is a widely held belief that affective disorders are progressive of nature; however, some recent reviews have questioned this belief. The objective of the present systematic literature review was to present evidence for associations between number of affective episodes and (i) the risk of recurrence of episodes, (ii) probability of recovery from episodes, (iii) severity of episodes, (iv) the threshold for developing episodes, and (v) progression of cognitive deficits in unipolar and bipolar disorders.

METHOD

A systematic review comprising an extensive literature search conducted in Medline, Embase, and PsychInfo up to September 2016 and including cross-references from identified papers and reviews.

RESULTS

Most of the five areas are superficially investigated and hampered by methodological challenges. Nevertheless, studies with the longest follow-up periods, using survival analysis methods, taking account of the individual heterogeneity all support a clinical progressive course of illness. Overall, increasing number of affective episodes seems to be associated with (i) increasing risk of recurrence, (ii) increasing duration of episodes, (iii) increasing symptomatic severity of episodes, (iv) decreasing threshold for developing episodes, and (v) increasing risk of developing dementia.

CONCLUSION

Although the course of illness is heterogeneous, there is evidence for clinical progression of unipolar and bipolar disorders.

Predictors of the discrepancy between objective and subjective cognition in bipolar disorder: a novel methodology

OBJECTIVE

The poor relationship between subjective and objective cognitive impairment in bipolar disorder (BD) is well-established. However, beyond simple correlation, this has not been explored further using a methodology that quantifies the degree and direction of the discrepancy. This study aimed to develop such a methodology to explore clinical characteristics predictive of subjective-objective discrepancy in a large BD patient cohort.

METHODS

Data from 109 remitted BD patients and 110 healthy controls were pooled from previous studies, including neuropsychological test scores, self-reported cognitive difficulties, and ratings of mood, stress, socio-occupational capacity, and quality of life. Cognitive symptom 'sensitivity' scores were calculated using a novel methodology, with positive scores reflecting disproportionately more subjective complaints than objective impairment and negative values reflecting disproportionately more objective than subjective impairment ('stoicism').

RESULTS

More subsyndromal depressive and manic symptoms, hospitalizations, BD type II, and being male positively predicted 'sensitivity', while higher verbal IQ predicted more 'stoicism'. 'Sensitive' patients were characterized by greater socio-occupational difficulties, more perceived stress, and lower quality of life.

CONCLUSION

Objective neuropsychological assessment seems especially warranted in patients with (residual) mood symptoms, BD type II, chronic illness, and/or high IQ for correct identification of cognitive deficits before commencement of treatments targeting cognition.

Systematic review of randomized controlled trials of candidate treatments for cognitive impairment in depression and methodological challenges in the field

Cognitive impairment is a core feature of Major Depressive Disorder (MDD) but treatments targeting cognition are lacking. Numerous pre-clinical and clinical studies have investigated potential cognition treatments, but overall the evidence is conflicting. We conducted a systematic search following the PRISMA guidelines on PubMed and PsychInfo to evaluate the extant evidence and methodological challenges in randomized controlled trials (RCTs) of biological, psychological and behavioural candidate treatments targeting cognition in MDD. Inclusion criteria were RCTs with a placebo control assessing potential pro-cognitive effects of candidate treatments in MDD. Two independent authors reviewed the studies and assessed their risk of bias with the Cochrane Collaboration׳s Risk of Bias tool. Twenty-eight eligible studies (24 biological and four psychological or behavioural studies) were identified. Cognition was the primary treatment target in ten (36%) trials and an additional treatment outcome together with mood symptoms in 18 (64%) trials. The risk of bias was high or unclear in 93% of trials due to potential selective outcome reporting or 'pseudospecificity' (unspecific cognitive improvement due to reduced depression severity), and/or insufficient details on how the allocation sequence was generated or how blinding was maintained. Several promising treatments were identified, including vortioxetine, erythropoietin, transcranial direct current stimulation and cognitive remediation. However, several common methodological challenges may impede advances in the field. In particular, future trials should select one cognitive composite score as primary outcome, screen for cognitive impairment before inclusion of participants and address 'pseudospecificity' issues. Together, these strategies may improve the success of future cognition trials in MDD.

Unaffected twins discordant for affective disorders show changes in anterior callosal white matter microstructure

OBJECTIVE

The neurobiological mechanisms mediating an increased risk to develop affective disorders remain poorly understood. In a group of individuals with a family history of major depressive (MDD) or bipolar disorder (BD), we investigated the microstructural properties of white matter fiber tracts, that is, cingulum bundle, uncinate fasciculus, anterior limb of the internal capsule, and corpus callosum, that facilitate the communication between brain regions implicated in affective disorders.

METHOD

Eighty-nine healthy mono- or dizygotic twins with a co-twin diagnosed with MDD or BD (high-risk) and 57 healthy twins with a co-twin with no familial history of affective disorders (low-risk) were included in a diffusion tensor imaging study.

RESULT

The high-risk group showed decreased fractional anisotropy (FA), a measure of water diffusion directionality, and increased radial diffusivity in the anterior region of corpus callosum compared to the low-risk group. This abnormality was not associated with zygosity or type of depressive disorder of co-twin.

CONCLUSION

The observed decreased anterior callosal fiber FA in the high-risk group may be indicative of a compromised interhemispheric communication between left and right frontal regions critically involved in mood regulation. Reduced anterior callosal FA may act as a vulnerability marker for affective disorders in individuals at familial risk.

Effects of erythropoietin on memory-relevant neurocircuitry activity and recall in mood disorders

OBJECTIVE

Erythropoietin (EPO) improves verbal memory and reverses subfield hippocampal volume loss across depression and bipolar disorder (BD). This study aimed to investigate with functional magnetic resonance imaging (fMRI) whether these effects were accompanied by functional changes in memory-relevant neuro-circuits in this cohort.

METHOD

Eighty-four patients with treatment-resistant unipolar depression who were moderately depressed or BD in remission were randomized to eight weekly EPO (40 000 IU) or saline infusions in a double-blind, parallel-group design. Participants underwent whole-brain fMRI at 3T, mood ratings, and blood tests at baseline and week 14. During fMRI, participants performed a picture encoding task followed by postscan recall.

RESULTS

Sixty-two patients had complete data (EPO: N = 32, saline: N = 30). EPO improved picture recall and increased encoding-related activity in dorsolateral prefrontal cortex (dlPFC) and temporo-parietal regions, but not in hippocampus. Recall correlated with activity in the identified dlPFC and temporo-parietal regions at baseline, and change in recall correlated with activity change in these regions from baseline to follow-up across the entire cohort. The effects of EPO were not correlated with change in mood, red blood cells, blood pressure, or medication.

CONCLUSION

The findings highlight enhanced encoding-related dlPFC and temporo-parietal activity as key neuronal underpinnings of EPO-associated memory improvement.

Voice analysis as an objective state marker in bipolar disorder

Changes in speech have been suggested as sensitive and valid measures of depression and mania in bipolar disorder. The present study aimed at investigating (1) voice features collected during phone calls as objective markers of affective states in bipolar disorder and (2) if combining voice features with automatically generated objective smartphone data on behavioral activities (for example, number of text messages and phone calls per day) and electronic self-monitored data (mood) on illness activity would increase the accuracy as a marker of affective states. Using smartphones, voice features, automatically generated objective smartphone data on behavioral activities and electronic self-monitored data were collected from 28 outpatients with bipolar disorder in naturalistic settings on a daily basis during a period of 12 weeks. Depressive and manic symptoms were assessed using the Hamilton Depression Rating Scale 17-item and the Young Mania Rating Scale, respectively, by a researcher blinded to smartphone data. Data were analyzed using random forest algorithms. Affective states were classified using voice features extracted during everyday life phone calls. Voice features were found to be more accurate, sensitive and specific in the classification of manic or mixed states with an area under the curve (AUC)=0.89 compared with an AUC=0.78 for the classification of depressive states. Combining voice features with automatically generated objective smartphone data on behavioral activities and electronic self-monitored data increased the accuracy, sensitivity and specificity of classification of affective states slightly. Voice features collected in naturalistic settings using smartphones may be used as objective state markers in patients with bipolar disorder.

Neural correlates of improved executive function following erythropoietin treatment in mood disorders

BACKGROUND

Cognitive dysfunction in depression and bipolar disorder (BD) is insufficiently targeted by available treatments. Erythropoietin (EPO) increases neuroplasticity and may improve cognition in mood disorders, but the neuronal mechanisms of these effects are unknown. This functional magnetic resonance imaging (fMRI) study investigated the effects of EPO on neural circuitry activity during working memory (WM) performance.

METHOD

Patients with treatment-resistant major depression, who were moderately depressed, or with BD in partial remission, were randomized to eight weekly infusions of EPO (40 000 IU) (N = 30) or saline (N = 26) in a double-blind, parallel-group design. Patients underwent fMRI, mood ratings and blood tests at baseline and week 14. During fMRI patients performed an n-back WM task.

RESULTS

EPO improved WM accuracy compared with saline (p = 0.045). Whole-brain analyses revealed that EPO increased WM load-related activity in the right superior frontal gyrus (SFG) compared with saline (p = 0.01). There was also enhanced WM load-related deactivation of the left hippocampus in EPO-treated compared to saline-treated patients (p = 0.03). Across the entire sample, baseline to follow-up changes in WM performance correlated positively with changes in WM-related SFG activity and negatively with hippocampal response (r = 0.28-0.30, p < 0.05). The effects of EPO were not associated with changes in mood or red blood cells (p ⩾0.08).

CONCLUSIONS

The present findings associate changes in WM-load related activity in the right SFG and left hippocampus with improved executive function in EPO-treated patients.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov: NCT00916552.

Rates and predictors of remission, recurrence and conversion to bipolar disorder after the first lifetime episode of depression--a prospective 5-year follow-up study

BACKGROUND

In depression, non-remission, recurrence of depressive episodes after remission and conversion to bipolar disorder are crucial determinants of poor outcome. The present study aimed to determine the cumulative incidences and clinical predictors of these long-term outcomes after the first lifetime episode of depression.

METHOD

A total of 301 in- or out-patients aged 18-70 years with a validated diagnosis of a single depressive episode were assessed from 2005 to 2007. At 5 years of follow-up, 262 patients were reassessed by means of the life chart method and diagnostic interviews from 2011 to 2013. Cumulative incidences and the influence of clinical variables on the rates of remission, recurrence and conversion to bipolar disorder, respectively, were estimated by survival analysis techniques.

RESULTS

Within 5 years, 83.3% obtained remission, 31.5% experienced recurrence of depression and 8.6% converted to bipolar disorder (6.3% within the first 2 years). Non-remission increased with younger age, co-morbid anxiety and suicidal ideations. Recurrence increased with severity and treatment resistance of the first depression, and conversion to bipolar disorder with treatment resistance, a family history of affective disorder and co-morbid alcohol or drug abuse.

CONCLUSIONS

The identified clinical characteristics of the first lifetime episode of depression should guide patients and clinicians for long-term individualized tailored treatment.

Daily electronic self-monitoring in bipolar disorder using smartphones - the MONARCA I trial: a randomized, placebo-controlled, single-blind, parallel group trial

BACKGROUND

The number of studies on electronic self-monitoring in affective disorder and other psychiatric disorders is increasing and indicates high patient acceptance and adherence. Nevertheless, the effect of electronic self-monitoring in patients with bipolar disorder has never been investigated in a randomized controlled trial (RCT). The objective of this trial was to investigate in a RCT whether the use of daily electronic self-monitoring using smartphones reduces depressive and manic symptoms in patients with bipolar disorder.

METHOD

A total of 78 patients with bipolar disorder according to ICD-10 criteria, aged 18-60 years, and with 17-item Hamilton Depression Rating Scale (HAMD-17) and Young Mania Rating Scale (YMRS) scores ≤17 were randomized to the use of a smartphone for daily self-monitoring including a clinical feedback loop (the intervention group) or to the use of a smartphone for normal communicative purposes (the control group) for 6 months. The primary outcomes were differences in depressive and manic symptoms measured using HAMD-17 and YMRS, respectively, between the intervention and control groups.

RESULTS

Intention-to-treat analyses using linear mixed models showed no significant effects of daily self-monitoring using smartphones on depressive as well as manic symptoms. There was a tendency towards more sustained depressive symptoms in the intervention group (B = 2.02, 95% confidence interval -0.13 to 4.17, p = 0.066). Sub-group analysis among patients without mixed symptoms and patients with presence of depressive and manic symptoms showed significantly more depressive symptoms and fewer manic symptoms during the trial period in the intervention group.

CONCLUSIONS

These results highlight that electronic self-monitoring, although intuitive and appealing, needs critical consideration and further clarification before it is implemented as a clinical tool.

Different neural and cognitive response to emotional faces in healthy monozygotic twins at risk of depression

BACKGROUND

Negative cognitive bias and aberrant neural processing of emotional faces are trait-marks of depression. Yet it is unclear whether these changes constitute an endophenotype for depression and are also present in healthy individuals with hereditary risk for depression.

METHOD

Thirty healthy, never-depressed monozygotic (MZ) twins with a co-twin history of depression (high risk group: n = 13) or without co-twin history of depression (low-risk group: n = 17) were enrolled in a functional magnetic resonance imaging (fMRI) study. During fMRI, participants viewed fearful and happy faces while performing a gender discrimination task. After the scan, they were given a faces dot-probe task, a facial expression recognition task and questionnaires assessing mood, personality traits and coping strategies.

RESULTS

High-risk twins showed increased neural response to happy and fearful faces in dorsal anterior cingulate cortex (ACC), dorsomedial prefrontal cortex (dmPFC), pre-supplementary motor area and occipito-parietal regions compared to low-risk twins. They also displayed stronger negative coupling between amygdala and pregenual ACC, dmPFC and temporo-parietal regions during emotional face processing. These task-related changes in neural responses in high-risk twins were accompanied by impaired gender discrimination performance during face processing. They also displayed increased attention vigilance for fearful faces and were slower at recognizing facial expressions relative to low-risk controls. These effects occurred in the absence of differences between groups in mood, subjective state or coping.

CONCLUSIONS

Different neural response and functional connectivity within fronto-limbic and occipito-parietal regions during emotional face processing and enhanced fear vigilance may be key endophenotypes for depression.

Altered reward processing in the orbitofrontal cortex and hippocampus in healthy first-degree relatives of patients with depression

BACKGROUND

Healthy first-degree relatives of patients with major depression (rMD+) show brain structure and functional response anomalies and have elevated risk for developing depression, a disorder linked to abnormal serotonergic neurotransmission and reward processing.

METHOD

In a two-step functional magnetic resonance imaging (fMRI) investigation, we first evaluated whether positive and negative monetary outcomes were differentially processed by rMD+ individuals compared to healthy first-degree relatives of control probands (rMD-). Second, in a double-blinded placebo-controlled randomized trial we investigated whether a 4-week intervention with the selective serotonergic reuptake inhibitor (SSRI) escitalopram had a normalizing effect on behavior and brain responses of the rMD+ individuals.

RESULTS

Negative outcomes increased the probability of risk-averse choices in the subsequent trial in rMD+ but not in rMD- individuals. The orbitofrontal cortex (OFC) displayed a stronger neural response when subjects missed a large reward after a low-risk choice in the rMD+ group compared to the rMD- group. The enhanced orbitofrontal response to negative outcomes was reversed following escitalopram intervention compared to placebo. Conversely, for positive outcomes, the left hippocampus showed attenuated response to high wins in the rMD+ compared to the rMD- group. The SSRI intervention reinforced the hippocampal response to large wins. A subsequent structural analysis revealed that the abnormal neural responses were not accounted for by changes in gray matter density in rMD+ individuals.

CONCLUSIONS

Our study in first-degree relatives of depressive patients showed abnormal brain responses to aversive and rewarding outcomes in regions known to be dysfunctional in depression. We further confirmed the reversal of these aberrant activations with SSRI intervention.

Cohabitation patterns among patients with severe psychiatric disorders in the entire Danish population

BACKGROUND

Assortative mating has been demonstrated in mental disorders but the extent of cohabitation between patients with clinically diagnosed psychiatric disease has been poorly explored. Method We conducted a register-based study of all Danes between 18 and 70 years of age in a 13-year observational period, linking data on individuals' contacts with psychiatric services with data on individuals' cohabitation status. Two different Poisson regression analyses were performed: the first comparing the rates of commencing cohabitation with a psychiatric patient between individuals, depending on whether the individuals themselves had, or did not have, a psychiatric diagnosis; the second comparing the incidence rates of psychiatric diagnoses for individuals cohabitating with psychiatric patients with the similar rates for individuals living with unaffected cohabitants.

RESULTS

In total, 159 929 (5.0%) out of 3 204 633 individuals were given a psychiatric diagnosis during the study period. Diagnosed individuals had an overall rate ratio (RR) of commencing cohabitation with a psychiatric patient of 1.95 [95% confidence interval (CI) 1.90-2.00] for women and 1.65 (95% CI 1.61-1.69) for men, when compared with unaffected individuals. The overall RR of receiving a psychiatric diagnosis while cohabitating with a psychiatric patient was 2.40 (95% CI 2.31-2.49) for women and 2.91 (95% CI 2.81-3.01) for men, when compared with those cohabitating with unaffected individuals. Individuals with schizophrenia and men with bipolar disorder had the highest RR of commencing cohabitation with a cohabitant with a similar diagnosis.

CONCLUSIONS

Cohabitation among individuals with severe psychiatric disorders is increased. This has implications for research and for the clinical management of patients.

Decreased levels of brain-derived neurotrophic factor in the remitted state of unipolar depressive disorder

OBJECTIVE

Decreased levels of peripheral brain-derived neurotrophic factor (BDNF) have been associated with depression. It is uncertain whether abnormally low levels of BDNF in blood are present beyond the depressive state and whether levels of BDNF are associated with the course of clinical illness.

METHOD

Whole-blood BDNF levels were measured in blood samples from patients with unipolar disorder in a sustained state of clinical remission and in a healthy control group. Participants were recruited via Danish registers, a method that benefits from the opportunity to obtain well-matched community-based samples as well as providing a high diagnostic validity of the patient sample.

RESULTS

A total of 85 patients and 50 controls were included in the study. In multiple linear regression analyses, including the covariates age, gender, 17-item Hamilton Depression Rating Scale scores, body-mass index, education, smoking and physical exercise, patients with unipolar depressive disorder had decreased levels of BDNF compared to healthy control individuals [B = -7.4, 95% CI (-11.2, -3.7), = 0.21 P < 0.001]. No association between course of clinical illness and BDNF levels was present.

CONCLUSION

Whole-blood BDNF levels seem to be decreased in patients remitted from unipolar depressive disorder, suggesting that neurotrophic changes may exist beyond the depressive state.

The cumulative load of depressive illness is associated with cognitive function in the remitted state of unipolar depressive disorder

OBJECTIVE

To investigate whether the cumulative number, duration and subtypes (severity and presence of psychotic features) of previous episodes of depression in patients with unipolar depressive disorder in a remitted state are associated with decreased global cognitive function.

METHODS

Via the Danish registers individuals between 40 and 80 years of age were identified: (1) patients with a diagnosis of unipolar disorder at their first discharge from a psychiatric hospital in the period 1994 to 2002, and (2) gender and age matched control individuals. The participants were assessed with the Cambridge Cognitive Examination (CAMCOG), which provides a composite measure of global cognitive function.

RESULTS

A total of 88 patients and 50 controls accepted our invitation to participate, fulfilled the selection criteria and were included in the study. The cumulative duration of depressive episodes was associated with a decreased CAMCOG score adjusted for age, gender, education, premorbid IQ and residual depressive symptoms (B=-0.14, 95% C.I. (-0.26, -0.02), R(2)adj=0.31, P=.02). Significant associations were also found between CAMCOG score and the cumulative duration and total number of depressive episodes with psychotic features, respectively.

CONCLUSION

Our findings suggest that cognitive dysfunction is associated with the cumulative duration of depressive episodes, and that, in particular, depressive episodes with psychotic features in the course of illness may be a significant predictor of future impairment of cognitive function.

Psychometric validation and clinical validity of the Minor Melancholia Mood Checklist (MMCL-32)

BACKGROUND

The Minor Melancholia Mood Checklist (MMCL-32) was developed to identify sub-threshold states of major depression. The MMCL-32 can be considered as the counterpole to the Hypomanic Check List (HCL-32).

METHODS

Principal component analysis (PCA) without rotation was used to identify a bidirectorial principal component. To evaluate the clinical validity of the bidirectorial factors, with reference to brief recurrent depression, the Bech-Rafaelsen Melancholia Scale was used.

RESULTS

We included 59 patients with bipolar I disorder (SCID criteria) and 57 patients with unipolar depression (more than one major depressive episode without hypomanic or manic episodes). They were all outpatients, but had recently been discharged from inpatient treatment. The PCA identified two contrasting factors: 17 items with negative loadings (psychasthenic depression factor) and 15 items with positive loadings (cognitive depression factor). When PCA was applied exclusively to the bipolar patients, 5 items within the cognitive factor were identified. When applied exclusively to the unipolar patients, 5 items within the psychasthenic factor were identified. The non-remitted bipolar patients scored higher on the cognitive factor (P=0.01) than the remitted. On the psychasthenic factor (P=0.06), the non-remitted unipolar patients scored higher than the remitted patients.

CONCLUSION

The MMCL-32 was found psychometrically valid in measuring sub-threshold states of major depression with rather specific factors for bipolar and unipolar depression. Focusing on these factors could be a clinical aid to distinguish patients at risk of developing a bipolar course.

From items to syndromes in the Hypomania Checklist (HCL-32): psychometric validation and clinical validity analysis

BACKGROUND

The Hypomania Checklist (HCL-32) was developed to identify subthreshold bipolarity in patients with major depression. An HCL-32 version with fewer items has been suggested.

METHODS

Principal component analysis (PCA) without rotation was used to identify active/elevated mood versus risk-taking/irritable behaviour in the HCL-32. Using the Bech-Rafaelsen Mania Scale as index of clinical validity a shorter version was developed. Item response theory analysis was used to evaluate whether the total score of the HCL-32 was sufficient to measure subthreshold bipolarity. The short 13-item Mood Disorder Questionnaire (MDQ) was used for comparison.

RESULTS

In accordance with the SCID-II criteria, we included 59 bipolar I and 63 unipolar (depressed) outpatients who had recently been discharged from inpatient treatment. In the HCL-32, PCA identified the two contrasting factors: active/elevated mood versus risk-taking/irritable behaviour. The clinical validation analysis focussed on 20 HCL items as the most acceptable (HCL-20). Item response analysis accepted that the total scores of the HCL-32/HCL-20 were a sufficient statistic, as was the total score of the MDQ. Among the unipolar (depressed) patients not responding to their antidepressive medication, subtreshold bipolarity was identified in 55% of patients using the HCL-20, 36% using the HCL-32, but only 18% using the MDQ.

LIMITATIONS

Only outpatients recently discharged from inpatient treatment were studied. A further limitation is that 9.5% of the unipolar patients had only suffered from one episode, which, however had led to hospitalisation.

CONCLUSION

The HCL-20 was found to identify subthreshold bipolarity in up to 55% of inpatients with major depressive disorder not responding to antidepressive medication.

The prevalence of mixed episodes during the course of illness in bipolar disorder

OBJECTIVE

To investigate the prevalence of mixed episodes during the course of illness in bipolar disorder.

METHOD

A total of 1620 patients with an ICD-10 diagnosis of bipolar affective disorder at the first psychiatric contact were identified in a period from 1994 to 2003 in Denmark and the prevalence of mixed, depressive and hypomanic/manic episodes were calculated at each episode.

RESULTS

The prevalence of mixed episodes increased from the first episode to the tenth episode, however, only for women (6.7% of the first episodes leading to psychiatric care compared with 18.2% of the tenth episodes). For men, the prevalence of mixed episodes was constantly low. At all episodes, the presence of a current mixed episode increased the risk substantially of getting a future mixed episode.

CONCLUSION

Clinicians should pay more attention to mixed episodes, especially among women, as they may represent an increasing treatment challenge as the illness progress.

Personality traits in unaffected twins discordant for affective disorder

OBJECTIVE

To examine whether a high genetic liability to develop affective disorder is associated with specific personality traits.

METHOD

A cross-sectional, high-risk, case-control study. Through nation-wide registers, healthy monozygotic (MZ) and dizygotic (DZ) twins with (high-risk twins) and without (the control group/low-risk twins) a co-twin history of affective disorder were identified. Personality traits were compared for a total of 211 high-risk and low-risk twins.

RESULTS

In univariate analyses, the high-risk twins had a higher level of neuroticism than the control twins (P = 0.03). In multivariate analyses, a high genetic liability to affective disorder was not significantly associated with neuroticism but correlated to sex, minor psychopathology and recent life events.

CONCLUSION

A high genetic liability to affective disorder showed an association with neuroticism, but the association interacts with other predictors of affective disorder such as female gender, minor psychopathology and recent adversity.

Depressive disorders and anti-parkinson drug treatment: a case register study

OBJECTIVE

To estimate the rate of treatment with anti-parkinson drugs (APD) among patients with depression.

METHOD

In a nationwide case register linkage study, all persons with a main diagnosis of depression during 5 years were identified. A control group of persons with diagnoses of osteoarthritis was included. The subsequent risk of getting treatment with APD was estimated for the two groups. Statistical analyses involved Poisson's regression and competing risk models.

RESULTS

A total of 14 991 persons were included. The rate of getting APD was 2.57 (95% CI: 1.46-4.52) times higher for persons with depression than for persons with osteoarthritis. Overall, the rate was highest for men. However, women with depression had a 3.89 (95% CI: 1.98-7.62) times higher rate of APD treatment as women with osteoarthritis while no significant difference was found among men.

CONCLUSION

Provided that prescription of APD reflects the presence of Parkinson's disease, results support a positive statistical association between depressive disorders and Parkinson's disease.

Epidemiology of subtypes of depression

OBJECTIVE

There is a general clinical impression that depression differs qualitatively from non-depressive conditions, and that it can be identified as a categorical entity. In contrast, epidemiological studies support the view that depression is dynamic in nature and develops on a continuous scale. The present article reviews selected epidemiological studies of depressive subtypes.

METHOD

A selective review.

RESULTS

Prior studies have found no clear differences in clinical presentation or long-term outcome between patients with melancholic and with neurotic/reactive depression. In addition, recent studies suggest that there is no clear demarcation between mild, moderate, and severe depression, pointing toward a continuity rather than categories of illness. For the individual patient, depressive symptoms seem to change over time, fulfilling criteria for major depression, minor depression, dysthymia, and subsyndromal states; the association between stressful life events and depression appears to diminish with the number of depressive episodes. Finally, recent genetic findings are congruent with a model indicating that the majority of depressions develop in the interplay between genes and stressful experiences, whereas 'reactive' depressions and 'endogenous' depressions apparently exist at a lower prevalence.

CONCLUSION

Further longitudinal, analytical, and genetic epidemiologic studies are needed to reveal which conditions are mild and transient, and which may be precursors of more severe and substantial illness such as melancholia.

The internalising and externalising dimensions of affective symptoms in depressed (unipolar) and bipolar patients

OBJECTIVE

To analyse the internalising and externalising dimensions of affective states in depressed (unipolar) and bipolar patients approximately 2 years after discharge from psychiatric hospitals in Denmark.

METHOD

The 42-item symptom scale based on the Beck Depression Inventory was used for the measurement of both the internalising dimension of affective symptoms (depression including suicidal ideas, anxiety and asthenia) and the externalising dimension (mania). To supplement the latter dimension, the WHO-5 questionnaire was included. These questionnaires were mailed to a large population of patients with depressive (unipolar) or bipolar disorders, representative of patients treated in hospital settings in Denmark, approximately 2 years after discharge from hospital.

RESULTS

In total, 244 unipolars and 214 bipolars were included in the study. Mokken analysis showed that depressive (unipolar) patients could be measured more validly than bipolar patients on the internalising subscales of depression, anxiety and asthenia. On the externalising dimension of psychological well-being (WHO-5), both groups of patients could be validly measured. Approximately 2 years after discharge from hospital, around 36% of the unipolars and 19% of the bipolars had a moderate to severe depression. In a control group of healthy subjects, 4% had a moderate to severe depression. Less than 5% even in the bipolar group of patients were hypomanic.

CONCLUSION

Approximately 2 years after discharge from psychiatric hospitals in Denmark, depressive (unipolar) patients scored significantly higher than bipolar patients on the internalising dimension and suicidal ideas, and significantly lower on the externalising dimension of psychological well-being.

Temporal changes in suicide rates for persons treated and not treated with antidepressants in Denmark during 1995-1999

OBJECTIVE

To compare the temporal changes in suicide rate among patients treated with antidepressants with the change in suicide rate among persons who have not been treated with antidepressants during 1995-1999.

METHOD

In a historic prospective national pharmacoepidemiological register linkage study by using four Danish registers we included 438,625 patients who had purchased antidepressants, and compared them with 1,199,057 population based control persons. The annual rate of suicide was estimated using Poisson regression analyses.

RESULTS

The suicide rate decreased for persons treated with antidepressants as well as for persons not treated with antidepressants. The proportion of persons, who committed suicide and who had not been treated with antidepressants decreased. The reduction in suicide rate was more pronounced among persons treated with SSRIs or older antidepressants than among persons not treated with antidepressants.

CONCLUSION

Several factors contribute to the decreasing suicide rate. The most pronounced decrease in suicide rate was found among persons treated with antidepressants.

Treatment with antidepressants and lithium is associated with increased risk of treatment with antiparkinson drugs: a pharmacoepidemiological study

OBJECTIVE

To estimate the risk for persons treated with antidepressants or lithium of subsequent treatment with antiparkinson drugs (APD).

METHODS

The Danish national prescription database supplied data on all persons who received antidepressants, lithium, or antidiabetics (first control group). A second control group was included comprising persons from the general population. Outcome was purchase of APD and the study period was 1995 to 1999.

RESULTS

In total, 1 293 789 persons were included. The rate ratio of treatment with APD after treatment with antidepressants was 2.27 (95% CI 2.14 to 2.42) for men and 1.50 (95% CI 1.43 to 1.58) for women. Figures for lithium were almost identical.

CONCLUSION

Persons treated with antidepressants or lithium are at increased risk of subsequently treatment with APD, showing an association between anxiety/affective disorder and Parkinson's disease.

Increased relative risk of subsequent affective disorders in patients with a hospital diagnosis of obesity

OBJECTIVE

To investigate the risk of clinical affective disorders of patients who were hospitalized because of obesity in the study period 1 January 1977 to 31 December 1999.

METHOD

Using data from Danish hospital registers, three study cohorts were identified by their diagnoses at discharge from hospital: one cohort comprising all patients with a first hospital admission with an index diagnosis of obesity, and two control cohorts comprising all patients with a first hospital admission with an index diagnosis of osteoarthritis or of non-toxic goiter, respectively. Later admissions to psychiatric hospital wards with discharge diagnoses of affective disorders were used as outcome events. Rates of readmission were estimated using competing risks models in survival analyses. Age, sex, abuse, and calendar time were included as covariables in the analyses.

RESULTS

A study sample of 165,425 patients discharged with an index diagnosis was identified. In total, 1081 events occurred in the observation period. An index diagnosis of obesity was associated with an increased risk of affective-disorders hospitalization when compared with patients with osteoarthritis (Rate ratio: 1.35 (95% CI: 1.09-1.67)) and tended to be associated with an increased risk when compared to patients with non-toxic goiter (Rate ratio: 1.23 (95% CI: 0.99-1.53)). Patients with obesity diagnoses who did not have additional hospital diagnoses of substance- or alcohol abuse had a risk of affective disorders that was 1.55 (95% CI: 1.23-1.95) times greater than that of osteoarthritis patients without abuse diagnoses.

CONCLUSIONS

Patients hospitalized with obesity may be prone to developing affective disorders that require in-hospital treatment, but the excess risk is modest. Severe obesity seems to be associated with other risk factors for mood disorders than those related to comorbid alcohol- or substance abuse.

No association between the -399 C > T polymorphism of the neuropeptide Y gene and schizophrenia, unipolar depression or panic disorder in a Danish population

OBJECTIVE

A polymorphism in the promoter region of the NPY gene at position -399 C > T was recently reported to be associated with schizophrenia in a Japanese population and with treatment refractory unipolar depression in a Swedish population. The objective of this study was to investigate potential associations between the polymorphism and three psychiatric disorders in a Danish population.

METHOD

We investigated the occurrence of the polymorphism in patients with schizophrenia (n = 291), unipolar depression (n = 256) and panic disorder (n = 142) compared with controls (n = 716).

RESULTS

We detected the polymorphism -399 C > T at a frequency of 48% in controls. No significant differences were found between genotype or allele frequencies in controls vs. the patient groups.

CONCLUSION

The lack of association between the -399 C > T polymorphism and schizophrenia, unipolar depression or panic disorder, respectively, suggests that the polymorphism is not involved in the etiology of these disorders in the Danish population.