Autonomic modulation networks in schizophrenia: The relationship between heart rate variability and functional and structural connectivity in the brain

Heart rate variability (HRV), a measurement of autonomic nervous system (ANS) activity, has been found reduced in schizophrenia. The anterior cingulate cortex (ACC), which is important in regulating the ANS, is structurally and functionally affected in schizophrenia. We investigate the relationship between HRV and functional and structural connectivity of the ACC in patients with schizophrenia and healthy controls. Ten patients with a diagnosis of schizophrenia and ten healthy controls were recruited. Heart rate was monitored in a naturalistic out-of-clinic setting. Magnetic resonance imaging (MRI) was performed, including resting-state functional MRI and diffusion tensor imaging. Patients with schizophrenia had significantly lower HRV compared to controls. A positive correlation between ACC connectivity with the bilateral cerebellum and HRV was found in the patients. HRV was also positively correlated with amplitude of low frequency fluctuations (ALFF) in the cerebellum, and with axial diffusivity in the middle cerebellar peduncle, in the patients. There was a significant negative relationship between antipsychotic medication dosage, HRV and all neuroimaging measures related to HRV. We conclude that ACC connectivity seems to be affected in schizophrenia, both structurally and functionally, and that the ACC-cerebellum connectivity, as well as cerebellar function, is associated with ANS regulation in patients with schizophrenia.

Electrocardiographic signs of autonomic imbalance in medicated patients with first-episode schizophrenia spectrum disorders – relations to first treatment discontinuation and five-year remission status

Purpose

To explore measures in electrocardiograms (ECG) influenced by autonomic balance in early schizophrenia spectrum disorders and to examine their relation to subsequent first antipsychotic pharmacotherapy discontinuation and five-year remission status.

Subjects and methods

Twelve-lead ECGs were recorded at baseline in 58 patients with first-episode schizophrenia spectrum disorders and in 47 healthy controls of similar age. Selected ECG variables included heart rate and measures of repolarization. Pharmacotherapy data were extracted from medical records. At a five-year follow-up the patients were interviewed and assessed with the Positive and Negative Syndrome Scale.

Results

Patients had higher heart rate and a different ST-T pattern than the controls. High T-wave amplitudes in the leads aVF and V5 and ST-elevations in V5 were associated both with higher risk of an earlier discontinuation of first antipsychotic pharmacotherapy and with non-remission five years later.

Discussion and conclusion

In this longitudinal cohort study, simple ECG measures influenced by autonomic balance in the early phase of schizophrenia spectrum disorders contained prognostic information. As this is the first report of this association and is based on a relatively small sample, the results should be interpreted with caution.

Substance use disorders and risk for treatment resistant depression: a population-based, nested case-control study

BACKGROUND AND AIMS

Treatment-resistant depression (TRD), defined as inadequate treatment response after at least two adequate treatment trials, is common among patients initiating antidepressant treatment. Current or previous substance use disorders (SUD) are common among patients with depression and often lead to worse treatment outcomes. However, in clinical studies, SUD have not been found to increase the risk for TRD. The aim of this study was to investigate the association between SUD and TRD.

DESIGN

Nested case-control study.

SETTING

Nation-wide governmental health-care registers in Sweden.

CASES AND CONTROLS

Data on prescribed drugs and diagnoses from specialized health care were used to establish a prospectively followed cohort of antidepressant initiators with depression (n = 121 669) from 2006 to 2014. Of these, 15 631 patients (13%) were defined as TRD cases, with at least three treatment trials within a single depressive episode. Each case with TRD was matched on socio-demographic data with five controls with depression.

MEASUREMENTS

Crude and adjusted odds ratios (aOR) with 95% confidence intervals (CI) estimated the association between TRD and SUD diagnosis and/or treatment in five different time intervals until the time for fulfillment of TRD definition for the case. The analysis was adjusted for clinical and socio-demographic covariates.

FINDINGS

Having any SUD during, or ≤ 180 days before start of, antidepressant treatment was associated with almost double the risk for TRD [≤ 180 days before: adjusted OR (aOR) = 1.86, CI = 1.70-2.05]. Increased risks for TRD were found ≤ 180 days before treatment start for the subcategories of sedative use (aOR = 2.37; 1.88-2.99), opioids (aOR = 2.02; 1.48-2.75), alcohol (aOR = 1.77; CI = 1.59-1.98) and combined substance use (aOR = 2.31; 1.87-2.99).

CONCLUSIONS

Recent or current substance use disorders is positively associated with treatment resistance among patients initiating treatment for depression.

Exposure to risperidone versus other antipsychotics and risk of osteoporosis-related fractures: a population-based study

OBJECTIVE

Antipsychotics may increase serum prolactin, which has particularly been observed with risperidone. Further, hyperprolactinemia has been linked to osteoporosis-related fractures. Therefore, we investigated fracture risk in a nationwide cohort exposed to antipsychotics.

METHODS

Swedish registers were used to identify adults with two consecutive dispensations of risperidone (n = 38 211), other atypical antipsychotics not including paliperidone (n = 60 691), or typical antipsychotics (n = 17 445) within three months between 2006 and 2013. An osteoporosis-related fracture was defined as a non-open hip/femur fracture in primary analyses. Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Risperidone users were on average older (mean age of 68, 44, and 63 years for risperidone, other atypical antipsychotics, and typical antipsychotics respectively). Compared with other atypical antipsychotics, there was no association between risperidone and osteoporosis-related fractures in the overall (HR = 1.04, CI: 0.91-1.19) or age-stratified analyses. A significantly increased risk of typical antipsychotics (HR = 1.24, CI: 1.07-1.45) compared with other atypical antipsychotics remained for ages >45 years.

CONCLUSION

Risperidone does not appear to be associated with an increased risk of osteoporosis-related fracture compared with other atypical antipsychotic agents as a group. For typical antipsychotics, a moderately elevated risk of hip fractures was noted compared with other atypical antipsychotics, possibly because of residual confounding.

Phosphodiesterase 10A levels are related to striatal function in schizophrenia: a combined positron emission tomography and functional magnetic resonance imaging study

Pharmacological inhibition of phosphodiesterase 10A (PDE10A) is being investigated as a treatment option in schizophrenia. PDE10A acts postsynaptically on striatal dopamine signaling by regulating neuronal excitability through its inhibition of cyclic adenosine monophosphate (cAMP), and we recently found it to be reduced in schizophrenia compared to controls. Here, this finding of reduced PDE10A in schizophrenia was followed up in the same sample to investigate the effect of reduced striatal PDE10A on the neural and behavioral function of striatal and downstream basal ganglia regions. A positron emission tomography (PET) scan with the PDE10A ligand [¹¹C]Lu AE92686 was performed, followed by a 6 min resting-state magnetic resonance imaging (MRI) scan in ten patients with schizophrenia. To assess the relationship between striatal function and neurophysiological and behavioral functioning, salience processing was assessed using a mismatch negativity paradigm, an auditory event-related electroencephalographic measure, episodic memory was assessed using the Rey auditory verbal learning test (RAVLT) and executive functioning using trail-making test B. Reduced striatal PDE10A was associated with increased amplitude of low-frequency fluctuations (ALFF) within the putamen and substantia nigra, respectively. Higher ALFF in the substantia nigra, in turn, was associated with lower episodic memory performance. The findings are in line with a role for PDE10A in striatal functioning, and suggest that reduced striatal PDE10A may contribute to cognitive symptoms in schizophrenia.

Suicide Ideation and Behavior as Risk Factors for Subsequent Suicide in Schizophrenia: A Nested Case-Control Study

OBJECTIVE

To investigate suicide ideation and behavior as risk factors for suicide in schizophrenia during varying time periods.

METHOD

Cases were 84 patients who died by suicide within 5 years from diagnosis in a source population of patients discharged for the first time from psychiatric hospitals in Stockholm County, Sweden, with a schizophrenia spectrum diagnosis. One control was individually matched with each suicide case. Data were retrieved from clinical records in a blind fashion. Thoughts of death, thoughts of suicide, suicide plan, and suicide attempt during varying time periods were investigated as risk factors for subsequent completed suicide.

RESULTS

In adjusted analyses, thoughts of suicide, suicide plan, and suicide attempt were significantly associated with subsequent completed suicide in the following year. The highest suicide risk was found within a year following suicide attempt (adjusted OR 9.9, 95% confidence interval 2.5-39.0). The association between suicide ideation and behavior and subsequent suicide declined over time.

CONCLUSIONS

Several types of suicide ideation and behavior were associated with suicide, and the association was stronger for suicidal behavior. The clinical significance of suicidal communication appears highest during the following month or/and year. Many suicides occurred without recorded short-term suicidal communication.

Treatment-resistant depression as risk factor for substance use disorders-a nation-wide register-based cohort study

BACKGROUND AND AIMS

Treatment-resistant depression (TRD) is common among patients with major depressive disorder (MDD). MDD may increase the risk for developing substance use disorders (SUD). The aim of this study was to investigate the risk for developing SUD among patients with TRD compared with other depressed patients.

DESIGN

Observational cohort study.

SETTING

Nation-wide governmental health registers in Sweden.

PARTICIPANTS

All patients aged 18-69 years with an MDD diagnosis in specialized health care who had received at least one antidepressant prescription during 2006-14 were identified. Patients with at least three treatment trials within a single depressive episode were classified with TRD.

MEASUREMENTS

Patients with TRD were compared with the whole MDD cohort regarding risk for obtaining a SUD diagnosis or medication using survival analyses adjusted for socio-demographics and comorbidities.

FINDINGS

Of 121 669 MDD patients, 13% were classified with TRD. Among the patients without any history of SUD, patients with TRD had a risk increase for any SUD both ≤ 1 and > 1 year after antidepressant initiation [> 1 year hazard ratio (HR) = 1.4; 95% confidence interval (CI) = 1.3-1.5]. Risks were elevated for the subcategories of opioid (HR = 1.9, 95% CI = 1.4-2.5) and sedative SUD (HR = 2.7, 95% CI = 2.2-3.2). Patients with a history of SUD had a risk increase for any SUD ≤ 1 year after start of treatment (HR = 1.2, 95% CI = 1.1-1.4), and both ≤ 1 year and > 1 year for sedative (> 1 year HR = 2.0, 95% CI = 1.3-3.0) and multiple substance SUD (HR = 1.9, 95% CI = 1.4-2.5).

CONCLUSIONS

Patients with treatment-resistant depression may be at greater risk for substance use disorders compared with other patients with major depressive disorder. Patterns may differ for patients with and without a history of substance use disorders, and for different categories of substance use disorder.

Monotherapy vs. combination therapy for post mania maintenance treatment: A population based cohort study

In recent years, the use of atypical antipsychotics and combination therapy for relapse prevention in bipolar disorder has increased substantially. However, real-world data on the comparative effectiveness of these treatment options are largely non-existent. We conducted a population-based cohort study, using data from Swedish national registers. All patients aged 18-75 years who were hospitalized for mania 2006-2014 and filled at least one prescription of lithium, valproate, olanzapine, quetiapine, aripiprazole or any combination of these drugs were included, and followed for up to one year after hospital discharge, generating follow-up data from 5 713 hospitalizations. We used Cox proportional hazard regression models to study time to treatment failure for each individual drug and combination therapy, using lithium as comparator. Treatment failure was defined as treatment discontinuation, switch, or rehospitalization, and the results were adjusted for clinical and sociodemographic factors. We found that treatment failure occurred in 85% of cases and that the majority of combination therapies were associated with lower risks of treatment failure compared to monotherapies. Patients combining lithium + valproate + quetiapine had the lowest risk of treatment failure (adjusted HR [AHR] 0.40, 95% CI 0.30-0.54), followed by patients on lithium + valproate + olanzapine (AHR 0.55, 95% CI 0.45-0.68). In contrast, monotherapies with antipsychotics were associated with significantly higher risks of treatment failure compared to single use of lithium. In conclusion, our results support experimental findings, suggesting that combination therapy is more effective than monotherapy after a manic episode.

All-cause mortality in patients with treatment-resistant depression: a cohort study in the US population

BACKGROUND

Treatment-resistant depression (TRD) may represent a substantial proportion of major depressive disorder (MDD); however, the risk of mortality in TRD is still incompletely assessed.

METHODS

Data were obtained from Optum Clinformatics™ Extended, a US claims database. Date of the first antidepressant (AD) dispensing was designated as the index date for study entry and 6 months prior to that was considered the baseline period. Patients with MDD aged ≥ 18 years, index date between January 1, 2008 and September 30, 2015, no AD claims during baseline, and continuous enrollment in the database during baseline were included. Patients who started a third AD regimen after two regimens of appropriate duration were included in the TRD cohort. All-cause mortality was compared between patients with TRD and non-TRD MDD using a proportional hazards model and Kaplan-Meier estimate with TRD status being treated as a time-varying covariate. The model was adjusted for study year, age, gender, depression diagnosis, substance use disorder, psychiatric comorbidities, and Charlson comorbidity index.

RESULTS

Out of 355,942 patients with MDD, 34,176 (9.6%) met the criterion for TRD. TRD was associated with a significantly higher mortality compared with non-TRD MDD (adjusted HR: 1.29; 95% CI 1.22-1.38; p < 0.0001). Survival time was significantly shorter in the TRD cohort compared with the non-TRD MDD cohort (p < 0.0001).

CONCLUSIONS

Patients with TRD had a higher all-cause mortality compared with non-TRD MDD patients.

Initiation and long-term use of benzodiazepines and Z-drugs in bipolar disorder

OBJECTIVES

Increasing evidence points to the harmful effects of long-term benzodiazepine treatment. Our objective was to study the incidence of, and predictors for, long-term use of benzodiazepines and Z-drugs in bipolar disorder.

METHODS

We conducted a population-based cohort study, using data from Swedish national registers. Swedish residents aged 18-75 years with a recorded diagnosis of bipolar disorder or mania between July 2006 and December 2012, and no history of benzodiazepine/Z-drug use in the past year, were included. Patients were followed for 1 year with regard to prescription fills of benzodiazepines/Z-drugs. Initiators were followed for another year during which continuous use for >6 months was defined as "long-term". Patient and prescription characteristics were investigated as potential predictors for long-term use in multivariate logistic regression models.

RESULTS

Out of the 21 883 patients included, 29% started benzodiazepine/Z-drug treatment, of whom one in five became long-term users. Patients who were prescribed clonazepam or alprazolam had high odds for subsequent long-term use (adjusted odds ratios [aORs] 3.78 [95% confidence interval (CI) 2.24-6.38] and 2.03 [95% CI 1.30-3.18], respectively), compared to those prescribed diazepam. Polytherapy with benzodiazepines/Z-drugs also predicted long-term use (aOR 2.46, 95% CI 1.79-3.38), as did age ≥60 years (aOR 1.93, 95% CI 1.46-2.53, compared to age <30 years), and concomitant treatment with psychostimulants (aOR 1.78, 95% CI 1.33-2.39).

CONCLUSIONS

The incidence of subsequent long-term use among bipolar benzodiazepine initiators is high. Patients on clonazepam, alprazolam or benzodiazepine/Z-drug polytherapy have the highest risk of becoming long-term users, suggesting that these treatments should be used restrictively.

Mortality in treatment-resistant unipolar depression: A register-based cohort study in Sweden

BACKGROUND

The impact of treatment resistant depression (TRD) on mortality is not established.

METHODS

Using Swedish national registers, 118,774 patients between 18-69 years of age who had been prescribed an antidepressant and been diagnosed with depression in specialized care were identified. Patients with at least two additional treatment trials during the same depressive episode were classified as having TRD. Data on the covariates of sex, age, history of depression, self-harm, substance use disorders, and other psychiatric and somatic comorbidities was also used. Relative risks comparing TRD patients with other depressed patients were calculated as hazard ratios (HR) for all-cause mortality and for external and non-external causes of death, as well as excess mortality rate ratios (EMRR), with 95% confidence intervals (CI).

RESULTS

In total 15,013 patients (13%) were classified with TRD. Adjusted HR for all-cause mortality was 1.35 (95% CI 1.21-1.50). Mortality from external causes (including suicides and accidents) was markedly higher in TRD patients than in other depressed patients (HR 1.97; 1.69-2.29), while mortality from non-external causes was similar. The adjusted EMRR was 1.52 (1.31-1.76), highest among patients 18-29 years old (EMRR 2.03; 1.31-1.76) and patients without somatic comorbidity (EMRR 1.99; 1.63-2.43).

LIMITATIONS

Severity of depression and adherence to treatment were not available in the data.

CONCLUSIONS

Patients with TRD may have an increased all-cause mortality compared to other depressed patients, mainly for external causes of death. The relative mortality is highest among young and physically healthy patients.

Persistent tachycardia in clozapine treated patients: A 24-hour ambulatory electrocardiogram study

Tachycardia is associated with cardiovascular mortality. Tachycardia is also a known clozapine adverse effect. However, whether clozapine-associated tachycardia is persistent is not known. Thirty clozapine-treated patients with clinical tachycardia were investigated with 24-hour ambulatory electrocardiography (ECG). Baseline peripheral heart rate (HR) was 106.7±7.8. The ambulatory ECG 24-hour-HR was 98.7±9.7. Baseline HR and 24-hour-HR correlated strongly (r=0.74, p=0.000003). Daytime HR was 106.4±9.9 and nighttime HR 89.2±12.0. Low dose bisoprolol reduced HR significantly. The high 24-hour-HR indicates a persistent tachycardia. Tachycardia should not discourage from clozapine use but the findings indicate a need of guidelines for detection and treatment of clozapine-associated tachycardia.

Reducing the rehospitalization risk after a manic episode: A population based cohort study of lithium, valproate, olanzapine, quetiapine and aripiprazole in monotherapy and combinations

BACKGROUND

Data on real-world rehospitalization risks in patients using different drugs and combination therapies for relapse prevention after a manic episode is limited.

METHODS

We conducted a nationwide population based cohort study using data from Swedish national registers. Swedish residents aged 18-75 years who were hospitalized for a manic episode between July 1, 2006 and December 2, 2014 were included. Prescription fills of lithium, valproate, olanzapine, quetiapine and aripiprazole were recorded throughout the first four weeks after hospital discharge, after which the patients were followed for up to one year. General and treatment specific rehospitalization risks were determined and results were adjusted for clinical and sociodemographic factors.

RESULTS

The study included follow-up data from 6 502 hospitalizations for mania. Pharmacologic relapse prevention was used after 78% of these hospitalizations. Monotherapies and combination therapies were equally common. The average one-year rehospitalization risk for patients who did versus did not initiate prophylactic treatment was 39% and 46%, respectively. The lowest rehospitalization risks were seen in patients on combination therapy with olanzapine and valproate or olanzapine and lithium, experiencing one year rehospitalization risks of 32% and 34% (adjusted hazard ratios 0.76 (95% confidence interval [CI] 0.62-0.93) and 0.83 (95% CI 0.70-0.98), compared to lithium monotherapy).

LIMITATIONS

Register data does not provide information on all clinical parameters affecting treatment choices.

CONCLUSIONS

One-year rehospitalization rates after a manic episode are considerable also for patients who initiate prophylactic treatment. Combination therapies including olanzapine and a classic mood-stabilizer may be beneficial for reducing rehospitalization risks after a manic episode.

Striatal phosphodiesterase 10A and medial prefrontal cortical thickness in patients with schizophrenia: a PET and MRI study

The enzyme phosphodiesterase 10A (PDE10A) is abundant in striatal medium spiny neurons and has been implicated in the pathophysiology of schizophrenia in animal models and is investigated as a possible new pharmacological treatment target. A reduction of prefrontal cortical thickness is common in schizophrenia, but how this relates to PDE10A expression is unknown. Our study aim was to compare, we believe for the first time, the striatal non-displaceable binding potential (BP_ND) of the new validated PDE10A ligand [¹¹C]Lu AE92686 between patients with schizophrenia and healthy controls. Furthermore, we aimed to assess the correlation of PDE10A BP_ND to cortical thickness. Sixteen healthy male controls and 10 male patients with schizophrenia treated with clozapine, olanzapine or quetiapine were investigated with positron emission tomography (PET) and magnetic resonance imaging (MRI). Striatal binding potential (BP_ND) of [¹¹C]Lu AE92686 was acquired through dynamic PET scans and cortical thickness by structural MRI. Clinical assessments of symptoms and cognitive function were performed and the antipsychotic dosage was recorded. Patients with schizophrenia had a significantly lower BP_ND of [¹¹C]Lu AE92686 in striatum (P=0.003) than healthy controls. The striatal BP_ND significantly correlated to cortical thickness in the medial prefrontal cortex and superior frontal gyrus across patients with schizophrenia and healthy controls. No significant correlation was observed between the BP_ND for [¹¹C]Lu AE92686 in striatum and age, schizophrenia symptoms, antipsychotic dosage, coffee consumption, smoking, duration of illness or cognitive function in the patients. In conclusion, PDE10A may be important for functioning in the striato-cortical interaction and in the pathophysiology of schizophrenia.

Suicide risk and antipsychotic side effects in schizophrenia: nested case-control study

OBJECTIVE

This study explores suicide risk in schizophrenia in relation to side effects from antipsychotic medication.

METHODS

Among patients with a first clinical discharge diagnosis of schizophrenia or schizoaffective disorder in Stockholm County between 1984 and 2000 (n = 4000), those who died by suicide within 5 years from diagnosis were defined as cases (n = 84; 54% male). For each case, one individually matched control was identified from the same population. Information on antipsychotic side effects, including extrapyramidal symptoms (EPS) and akathisia, as well as prescriptions of anticholinergic medication, was retrieved from clinical records in a blinded fashion. Adjusted odds ratios (aORs) with 95% confidence intervals (CIs) of the association between suicide and side effects as well as anticholinergic medication were estimated using conditional logistic regression.

RESULTS

A lower suicide risk was found in patients with a history of EPS (aOR 0.33, 95% CI 0.12-0.94). There was no statistically significant association between akathisia or anticholinergic medication use and the suicide risk.

CONCLUSIONS

A lower suicide risk identified among patients with EPS could potentially reflect higher antipsychotic adherence, exposure to higher dosage, or polypharmacy among these patients. Copyright © 2016 John Wiley & Sons, Ltd.

Risk factors for suicide among patients with schizophrenia: a cohort study focused on cerebrospinal fluid levels of homovanillic acid and 5-hydroxyindoleacetic acid

BACKGROUND

The objective of this study was to investigate the association between 5-hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA) in cerebrospinal fluid (CSF), bullying, and later suicide among patients with schizophrenia.

METHODS

Ninety-nine patients with schizophrenia were included. Correlations of clinical factors, 5-HIAA and HVA, and later suicide were investigated.

RESULTS

Twelve patients committed suicide (12%) during a 28-year follow-up period. Later suicide was correlated to bullying in childhood (P=0.02) and a lower quotient of HVA/5-HIAA in CSF (P<0.05).

CONCLUSION

Suicide in schizophrenia is related to childhood exposedness and CSF neurotransmitter levels.

Higher mortality after myocardial infarction in patients with severe mental illness: a nationwide cohort study

OBJECTIVES

The aim of this study was to explore the impact of severe mental illness (SMI) on myocardial infarction survival and determine the influence of risk factor burden, myocardial infarction severity and different treatments.

DESIGN, SETTING AND PARTICIPANTS

This population-based cohort study, conducted in Sweden during the period 1997-2010, included all patients with a first diagnosis of myocardial infarction in the Swedish nationwide myocardial infarction register SWEDEHEART (n = 209 592). Exposure was defined as a diagnosis of SMI (i.e. bipolar disorder or schizophrenia) in the national patient register prior to infarction. Bias-minimized logistic regression models were identified using directed acyclic graphs and included covariates age, gender, smoking, diabetes, previous cardiovascular disease, myocardial infarction characteristics and treatment.

MAIN OUTCOME MEASURES

The outcomes were 30-day and 1-year mortality, obtained through linkage with national population registers.

RESULTS

Patients with bipolar disorder (n = 442) and schizophrenia (n = 541) were younger (mean age 68 and 63 years, respectively) than those without SMI (n = 208 609; mean age 71 years). The overall 30-day and 1-year mortality rates were 10% and 18%, respectively. Compared with patients without SMI, patients with SMI had higher 30-day [odds ratio (OR) 1.99, 95% confidence interval (CI) 1.55-2.56] and 1-year mortality (OR 2.11, 95% CI 1.74-2.56) in the fully adjusted model. The highest mortality was observed amongst patients with schizophrenia (30-day mortality: OR 2.58, 95% CI 1.88-3.54; 1-year mortality: OR 2.55, 95% CI 1.98-3.29).

CONCLUSION

SMI is associated with a markedly higher mortality after myocardial infarction, also after accounting for contributing factors. It is imperative to identify the reasons for this higher mortality.

Predictors for initiation of pharmacological prophylaxis in patients with newly diagnosed bipolar disorder--A nationwide cohort study

BACKGROUND

Treatment guidelines state that all patients with bipolar disorder should use pharmacological prophylaxis; however the actual use of prophylactic drugs after bipolar disorder diagnosis is unknown. Our aim was to assess the use of, and predictors for, pharmacoprophylaxis in newly diagnosed bipolar disorder patients.

METHODS

Data from three Swedish nationwide registers were obtained. We identified patients aged 18-75 with a first time diagnosis of bipolar disorder between 2006 and 2012 (n=31,770) and reviewed subsequent mood-stabilizer and antipsychotic prescription fills. In multivariable Cox regression models, we studied demographic and illness related factors as predictors of prescription fills after diagnosis.

RESULTS

In total, 72.2% (95% confidence interval [CI] 71.7-72.7%) of the patients filled a prescription of a prophylactic drug within 3 months after diagnosis. Pharmacological prophylaxis was mainly associated with a longer duration of hospitalization at bipolar disorder diagnosis (adjusted hazard ratio [AHR] 2.18; CI 2.02-2.35 for a hospitalization of ≥28 days compared to <7 days) and previous use of any mood-stabilizer or antipsychotic (inpatients: AHR 1.24; CI 1.17-1.31 and outpatients: AHR 1.78; CI 1.73-1.84).

LIMITATIONS

We had no information on drug prescriptions that were never filled.

CONCLUSIONS

The proportion of newly diagnosed bipolar disorder patients without pharmacological prophylaxis is substantial. Patients who are naïve to mood-stabilizers and antipsychotics and are hospitalized for a brief period at diagnosis are the ones least likely to initiate pharmacoprophylaxis, suggesting that this group deserves attention in order to improve the long term prognosis.