Striatal Dopamine Signals and Reward Learning

We are constantly bombarded by sensory information and constantly making decisions on how to act. In order to optimally adapt behavior, we must judge which sequences of sensory inputs and actions lead to successful outcomes in specific circumstances. Neuronal circuits of the basal ganglia have been strongly implicated in action selection, as well as the learning and execution of goal-directed behaviors, with accumulating evidence supporting the hypothesis that midbrain dopamine neurons might encode a reward signal useful for learning. Here, we review evidence suggesting that midbrain dopaminergic neurons signal reward prediction error, driving synaptic plasticity in the striatum underlying learning. We focus on phasic increases in action potential firing of midbrain dopamine neurons in response to unexpected rewards. These dopamine neurons prominently innervate the dorsal and ventral striatum. In the striatum, the released dopamine binds to dopamine receptors, where it regulates the plasticity of glutamatergic synapses. The increase of striatal dopamine accompanying an unexpected reward activates dopamine type 1 receptors (D1Rs) initiating a signaling cascade that promotes long-term potentiation of recently active glutamatergic input onto striatonigral neurons. Sensorimotor-evoked glutamatergic input, which is active immediately before reward delivery will thus be strengthened onto neurons in the striatum expressing D1Rs. In turn, these neurons cause disinhibition of brainstem motor centers and disinhibition of the motor thalamus, thus promoting motor output to reinforce rewarded stimulus-action outcomes. Although many details of the hypothesis need further investigation, altogether, it seems likely that dopamine signals in the striatum might underlie important aspects of goal-directed reward-based learning.

A Unified Framework for Dopamine Signals across Timescales

Rapid phasic activity of midbrain dopamine neurons is thought to signal reward prediction errors (RPEs), resembling temporal difference errors used in machine learning. However, recent studies describing slowly increasing dopamine signals have instead proposed that they represent state values and arise independent from somatic spiking activity. Here we developed experimental paradigms using virtual reality that disambiguate RPEs from values. We examined dopamine circuit activity at various stages, including somatic spiking, calcium signals at somata and axons, and striatal dopamine concentrations. Our results demonstrate that ramping dopamine signals are consistent with RPEs rather than value, and this ramping is observed at all stages examined. Ramping dopamine signals can be driven by a dynamic stimulus that indicates a gradual approach to a reward. We provide a unified computational understanding of rapid phasic and slowly ramping dopamine signals: dopamine neurons perform a derivative-like computation over values on a moment-by-moment basis.

The Ham D6 is more homogenous and as sensitive as the Ham D17

Objective

Using the data of a positive d.b.c.t. comparing an hypericum extract (W55570) to placebo in depressed patients we explored whether the Ham D6 was unidimentional and in case of a positive answer whether the total score was as sensitive as the total score of the Ham D17.

Methods

The study was a 6 weeks double blind placebo controlled trial comparing 300 mg of hypericum t.i.d (n = 186), to placebo (n = 189), in patients with a single or recurrent depression according to DSM-IV. Superiority of hypericum versus placebo on the main outcome criterion (HDRS 17) was already published.

The unidimensionality of the Hamilton depression scale 6 and 17 items were tested using a Mokken scale analysis. The effect size according to the initial severity of depression was calculated on the ITT last observation carried forward population.

Results

The Ham D6, covering the core symptoms of depression was unidimensional, implying that improving this score reflects a true antidepressant effect. The Ham D17 was not unidimensional.

Hypericum was an effective antidepressant in patients with a pre-treatment score of 12 or more (n = 208) on the Ham D6, the effect size was 0.46. No difference with placebo was observed for those with a score of less than 12 (n = 167).

Conclusions

For the evaluation of an antidepressant effect, because of its specificity and sensitivity, the Ham D6 should be used as a primary outcome measure rather than the Ham D17.

Quality of life measurement in the medical setting

Quality of life became a paradigm in the medical setting two decades ago. Although ‘humanistic’ psychologists still maintain that what can be specified and measured is precisely what is not quality of life, time has shown that the major components of quality of life in health and disease can be measured with an acceptable internal as well as external validity. Quality of life in randomized clinical trials is now the third dimension to be measured, the other dimensions are efficacy of the drug and adverse drug reactions. Among the major areas of external validity quality of life scales (eg the PCASEE questionnaire and the Psychological General Well-Being Schedule) have discriminating validity (the discrimination between treatments), predictive-validity (the prediction of relapse of illness), and teological validity (defining goal of treatment).

Quality of life instruments in depression

Major depression is one of the medical disorders in which quality of life instruments have most often been applied. It is important to distinguish between disease-dependent scales (ie, scales measuring the symptoms of major depression, such as the Beck Depression Inventory) and generic scales (ie, scales measuring self-reported states without reference to a specific disorder, such as the WHO well-being scale). The empirical use of generic scales for quality of life major depression has indicated that they can predict relapse and compliance. In the future, more trials comparing the different treatments with cost-effectiveness vs quality of life in major depression are required.

Depression and cognitive impairment in the elderly: a multicentre study

The present study, conducted in collaboration between the Departments of Psychiatry in Swiss Universities and the World Health Organization, had two main goals: to develop assessment methods which could subsequently be used in the Swiss centres in a standard manner; and to make arrangements for continuing collaboration between the centres in Switzerland and the acquisition of new knowledge about the distinctions between depression and cognitive impairment. For this aim, three different groups of elderly patients of either sex were selected during the period of November 1989 to July 1991 for inclusion in the study. The first two groups included the first ten patients of either sex over 60 years of age consecutively contacting the participating institutions and showing depression with or without clinically significant symptoms of cognitive impairment; the control group included patients showing no depression or clinically significant symptoms of cognitive impairment. A total of 125 patients were included in the initial evaluation, 69 of which were reassessed at a seven-month follow up (on average). Each patient was administered a number of clinician-rated or self-report instruments for the assessment of depression, cognitive impairment, disabilities, physical status and onset of disorders. The study has shown that a variety of instruments can be used for the reliable assessment of depression or cognitive impairment in the elderly; but the instruments for the assessment of depression differentiate only poorly between patients with or without cognitive impairment. Because of the importance of identifying both depressed and cognitively impaired patients among the elderly, different assessment instruments targeted at the different symptom clusters need to be administered simultaneously.

Post-stroke patients in rehabilitation. The relationship between biological impairment (CT scanning), physical disability and clinical depression

A study of 128 consecutive patients with thromboembolic stroke in a rehabilitation hospital from July 1988 to September 1990 found a prevalence of major depression of 17%. The patient population was described according to the principles of the World Health Organization's (WHO) International Classification of Impairments, Disabilities and Handicaps (ICIDH) according to biological impairment, measured by computerized tomography (CT) scanning of the brain and side of hemiparesis and physical disability, measured by functional movement and activities of daily living. Handicap, referring to the interaction between disability and the environmental situation, often defined as the subjective disadvantage of being ill, was not measured in this study. A stroke index with four items was generated from the parameters describing biological impairment and physical disability. The psychiatric rating scales (the 17-item Hamilton Scale for Depression (HAM-D), the Melancholia Scale [MES]and the Newcastle Diagnostic Depression Scale), and the new stroke-index showed adequate coefficients of Cronbach's alpha and Loevinger, suggesting that these scales have both adequate item correlation and homogeneity (adequate hierarchical structure). The impairment disability index of stroke thus seems to be a meaningful measurement of the specific factors of this disease. There was no correlation between the stroke-index and the psychiatric rating scales measuring the emotional dimension of disability caused by the disease expressed as depression. The results suggest that the depression found among stroke patients is not a simple reaction to the physical disability of the stroke.

Work-related stressors, depression and quality of life in Danish managers

Background

By use of valid questionnaires to investigate work-related stress and distress in Danish managers.

Methods

The survey focused on members of the Danish Association of Managers and Executives who no longer were active (formermanagers' group). Acting managers (active managers' group) served as controls. Questionnaires measuring stressors at work and general life events were used. For the measurement of distress, scales for depression and quality of life were used.

Results

The Mokken analysis proved the validity of the questionnaires, i.e. their summed-up total scores were sufficient statistics. No differences were found between former (n = 1256) and active managers (n = 942) as to life events. Approximately 20% of former managers were at risk of depression and 12% had developed major depression. Among the specific work-related stressors were role overload, lack of team spirit and lack of social support. The percentage of active managers at risk of or suffering from major depression did not differ significantly from the Danish general population. Approximately 37% of the former managers had a decreased well-being. Alcohol use was found to be significantly associated with depression.

Conclusions

The study identified specific work-related stressors in managers, 12% of whom developed a major depression.

Responsiveness of observer rating scales by analysis of number of days until improvement in patients with major depression

Several well-known observer scales, including the Hamilton Depression Scale (HAM-D), Montgomery-Åsberg Scale (MADRS), Major Depression Rating Scale (MDS), Melancholia Scale (MES), and Inventory for Depressive Symptomatology (IDS) used for measuring severity of depressive states have been compared by their responsiveness in an open trial including patients treated with a combination of citalopram and mianserin. The patients fulfilled the Diagnostic and Statistical Manual (DSM)-IV criteria for major depressive episode, and all scored 18 or more on the HAM-D before treatment. Onset of antidepressant action was defined as an improvement of rating scale scores of 25% or more of pre-treatment scores. A response to treatment was defined as a reduction of 50% or more on the pre-treatment scores. The results showed that the number of treatment days until improvement was 11 to 13 with no difference between the scales. The days until response were between 18 and 21 with no difference between the scales. In conclusion, the depression scales were found to be equal in their ability to detect changes in depressive symptoms during treatment. The mean of days to response was 19 for the combination of citalopram and mianserin. This is similar to the response for the combination of fluoxetine and pinolol.

Quality of life measurements in major depression

In randomized clinical trials in patients with major depression quality of life is considered as an important dimension of treatment outcome in relation to clinical efficacy and safety. The internal validity, reliability, as well as external validity of quality of life scales have been analysed. It is concluded that such scales have their most appropriate applicability in medicine and long-term trials with antidepressants.

Prevalence of depressive disorder among patients with fibromyalgia: Systematic review and meta-analysis

BACKGROUND

It is acknowledged that fibromyalgia (FM) as a medical (rheumatological) disorder and major depressive disorder (MDD) as a mental disorder often co-occurs, but the inconsistency is prevailing at study-level and no overall estimate of the co-occurrence exist.

AIMS

This systematic review and meta-analysis aimed to estimate the overall point- and life-time prevalence of MDD among FM patients based on structured clinical interviews (SCI); and to estimate the point-prevalence of MDD among FM patients based on screening symptom scales (SSS).

METHOD

The electronical databases MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and PsycINFO were searched for papers that reported on prevalence of MDD among FM patients. Eligible studies were included in a random effects meta-analysis pooling the prevalence of depression.

RESULTS

The literature search identified 11 eligible studies for the meta-analysis. For SCI, the overall pooled point-prevalence (PP) was 25% (95% CI 19 to 31%), and life-time prevalence (LP) was 65% (95% CI 59 to 71%). When estimating the PP with self-administered SSS the overall pooled PP was 45% (95% CI 32 to 59%), and a single clinician-administered SSS yielded a PP of 23% (95% CI 10 to 41%). There was low inconsistency for the SCI and high inconsistency for the SSS.

CONCLUSION

One fourth of all FM patients had MDD, and more than half experienced MDD during their life-time according to clinician-administered instruments. Prevalence of MDD was almost twice as high when using self-administered symptom scales and may be likely to overestimate the co-occurrence.

Differential Effects of Deep Brain Stimulation of the Internal Capsule and the Striatum on Excessive Grooming in Sapap3 Mutant Mice

BACKGROUND

Deep brain stimulation (DBS) is an effective treatment for patients with obsessive-compulsive disorder (OCD) that do not respond to conventional therapies. Although the precise mechanism of action of DBS remains unknown, modulation of activity in corticofugal fibers originating in the prefrontal cortex is thought to underlie its beneficial effects in OCD.

METHODS

To gain more mechanistic insight into DBS in OCD, we used Sapap3 mutant mice. These mice display excessive self-grooming and increased anxiety, both of which are responsive to therapeutic drugs used in OCD patients. We selected two clinically relevant DBS targets through which activity in prefronto-corticofugal fibers may be modulated: the internal capsule (IC) and the dorsal part of the ventral striatum (dVS).

RESULTS

IC-DBS robustly decreased excessive grooming, whereas dVS-DBS was on average less effective. Grooming was reduced rapidly after IC-DBS onset and reinstated upon DBS offset. Only IC-DBS was associated with increased locomotion. DBS in both targets induced c-Fos expression around the electrode tip and in different regions of the prefrontal cortex. This prefronto-cortical activation was more extensive after IC-DBS, but not associated with behavioral effects. Furthermore, we found that the decline in grooming cannot be attributed to altered locomotor activity and that anxiety, measured on the elevated plus maze, was not affected by DBS.

CONCLUSIONS

DBS in both the IC and dVS reduces compulsive grooming in Sapap3 mutant mice. However, IC stimulation was more effective, but also produced motor activation, even though both DBS targets modulated activity in a similar set of prefrontal cortical fibers.

The validity and sensitivity of PANSS-6 in treatment-resistant schizophrenia

OBJECTIVE

To test the validity and sensitivity of the six-item version (PANSS-6) of the 30-item Positive and Negative Syndrome Scale (PANSS-30) in treatment-resistant schizophrenia (TRS).

METHOD

Using data from the clozapine phase (2E) of the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) study, we investigated the following: (i) The scalability of PANSS-6 and PANSS-30; (ii) The correlation between PANSS-6 and PANSS-30 total scores; (iii) Whether PANSS-6 could identify cross-sectional symptom remission; and (iv) The efficacy of clozapine, olanzapine, risperidone and quetiapine in TRS using the 'speed of change' on PANSS-6 and PANSS-30 (change in total score per week) as outcome measures.

RESULTS

We found that (i) only PANSS-6 and not PANSS-30 was scalable; (ii) The correlation between PANSS-6 and PANSS-30 total scores was high (Spearman coefficient: 0.85), (iii) PANSS-6 accurately identified cross-sectional symptom remission as defined by the Andreasen et al. criteria; and (iv) The only antipsychotic that caused improvement (speed of change significantly lower than 0 during the first three months of treatment) was clozapine, both when using PANSS-6 (speed of change: -0.50 points/week; 95%CI: -0.84, -0.17) and PANSS-30 (speed of change: -1.41 points/week; 95%CI: -2.80, -0.02) as outcome measures.

CONCLUSION

PANSS-6 validly measures severity, remission and antipsychotic efficacy in TRS.

Conceptualizing patient-reported outcome measures for use within two Danish psychiatric clinical registries: description of an iterative co-creation process between patients and healthcare professionals

BACKGROUND

Denmark has national clinical indicator programs for adult patients diagnosed with depression and schizophrenia, respectively. Within each program, the responsible steering group (SG) decided to add some indicators based upon patient-reported outcome measures (PROMs).

AIMS

The primary aim was to describe the process of selecting PROMs and defining a national measurement concept for use in clinical practice and for indicator monitoring and the secondary aim s to collect patient recommendations for implementation.

METHODS

An interdisciplinary SG of healthcare professionals and a Patient Peer Board (PPB) representing both patient groups co-created the output in an iterative process. The work included literature search, PPB workshops, SG meetings, ratings of PROM topics and items, and a pilot. The PPB discussed the following: item relevance, mode of data collection, graphical format of the online PROMs, and display of results. Finally, requirements for PROM patient information were identified. Based upon input from the PPB, the SG selected the items and specified the measurement concept.

RESULTS

The PPB prioritized 20 of 53 suitable items and suggested alternative wording and answer categories. A pilot was performed and 19 items covering well-being, lack of well-being, impairment of functioning, and overall health were selected for clinical testing. The patients recommended concrete, unambiguous, easily understandable information and procedures for data collection and display of results.

CONCLUSIONS

The iterative co-creation process based upon a high degree of patient involvement resulted in a set of PROMs, a national measurement concept, and patient recommendations for implementation. The cooperation between patients and professionals was successful.

Effects of transcranial pulsed electromagnetic field stimulation on quality of life in Parkinson's disease

BACKGROUND AND PURPOSE

Pulsed electromagnetic fields induce a protective and anti-inflammatory effect in the nervous system primarily due to growth factor upregulation that possibly abates neurodegeneration in Parkinson's disease (PD). This study investigated treatment effects of transcranial pulsed electromagnetic fields (T-PEMFs) on quality of life in PD and the feasibility and safety of this treatment.

METHODS

In this double-blinded clinical study, 97 participants with idiopathic PD (Hoehn & Yahr stage I-IV), on optimal medical anti-parkinsonian treatment, were block randomized (3:3) to either active (n = 49) or placebo treatment (n = 48). Treatment with T-PEMFs entailed one daily 30-min home treatment for eight consecutive weeks. The 39-item Parkinson's Disease Questionnaire (PDQ-39) was assessed at baseline and endpoint. A special questionnaire was used to profile adverse events by interviewing the participants over the full treatment period. Treatment compliance was accounted for by daily treatment registration.

RESULTS

The active group improved with respect to clinical effect size for the two dimensions, i.e. mobility and activities of daily living, compared with the placebo group. No between-group differences were found for the remaining PDQ-39 dimensions. There were no between-group difference in adverse events. Treatment compliance was 97.9%.

CONCLUSION

Treatment with T-PEMFs improved mobility and activities of daily living scores for clinical effect size only in the active group, indicating a positive treatment response for motor symptoms. No difference was found between the two groups for the remaining PDQ-39 dimensions. The treatment had no or only mild adverse events and was performed with high compliance.

Diagnostic Conversion to Bipolar Disorder in Unipolar Depressed Patients Participating in Trials on Antidepressants

Objective

In unipolar depressed patients participating in trials on antidepressants, we investigated if illness characteristics at baseline could predict conversion to bipolar disorder.

Method

A long-term register-based follow-up study of 290 unipolar depressed patients with a mean age of 50.8 years (SD = 11.9) participating in three randomized trials on antidepressants conducted in the period 1985–1994. The independent effects of explanatory variables were examined by applying Cox regression analyses.

Results

The overall risk of conversion was 20.7%, with a mean follow-up time of 15.2 years per patient. The risk of conversion was associated with an increasing number of previous depressive episodes at baseline, [HR 1.18, 95% CI (1.10–1.26)]. No association with gender, age, age at first depressive episode, duration of baseline episode, subtype of depression or any of the investigated HAM-D subscales included was found.

Limitations

The patients were followed-up through the Danish Psychiatric Central Research Register, which resulted in inherent limitations such as possible misclassification of outcome.

Conclusion

In a sample of middle-aged hospitalized unipolar depressed patients participating in trials on antidepressants, the risk of conversion was associated with the number of previous depressive episodes. Therefore, this study emphasizes that unipolar depressed patients experiencing a relatively high number of recurrences should be followed more closely, or at least be informed about the possible increased risk of conversion.

PANSS-6: a brief rating scale for the measurement of severity in schizophrenia

OBJECTIVE

The 30-item Positive and Negative Syndrome Scale (PANSS-30) is the most widely used rating scale in schizophrenia, but too long for clinical use. Shorter PANSS versions have been proposed, including the PANSS-14 and PANSS-8. However, none of these PANSS versions has been validated using the parametric Rasch rating scale model, which evaluates 'scalability'. Scalability means that each item in a rating scale provides unique information regarding syndrome severity and is a statistical prerequisite for using the total score as a measure of overall severity.

METHOD

Based on data from two randomized placebo-controlled trials in schizophrenia, we tested the scalability of PANSS-30, PANSS-14 and PANSS-8 by means of the parametric Rasch rating scale model. Furthermore, we tested whether a scalable PANSS version could separate efficacy of haloperidol and sertindole from placebo.

RESULTS

Neither PANSS-30, PANSS-14 nor PANSS-8 was scalable. However, PANSS-6, consisting of the items: P1-Delusions, P2-Conceptual disorganization, P3-Hallucinations, N1-Blunted Affect, N4-Social withdrawal, N6-Lack of spontaneity and flow of conversation, was scalable. Furthermore, PANSS-6 captured superior symptom reduction and higher remission rates during treatment with haloperidol and sertindole vs. placebo.

CONCLUSION

PANSS-6 is a short schizophrenia severity rating scale that adequately separates antipsychotic efficacy from that of placebo.

Measuring euthymia within the Neuroticism Scale from the NEO Personality Inventory: A Mokken analysis of the Norwegian general population study for scalability

BACKGROUND

Whereas the Eysenck Neuroticism Scale only contains items covering negative mental health to measure dysthymia, the NEO Personality Inventory (NEO-PI) contains neuroticism items covering both negative mental health and positive mental health (or euthymia). The consequence of wording items both positively and negatively within the NEO-PI has never been psychometrically investigated. The aim of this study was to perform a validation analysis of the NEO-PI neuroticism scale.

METHODS

Using a Norwegian general population study we examined the structure of the negatively and positively formulated items by principal component analysis (PCA). The scalability of the identified two groups of euthymia versus dysthymia items was examined by Mokken analysis.

RESULTS

With a response rate of 90%, 1082 individuals with a completed NEO-PI were available. The PCA identified the neuroticism scale as the most distinct where 14 items had acceptable loadings for the euthymia subscale, another 14 items for the dysthymia subscale. However, the Mokken analysis coefficient of homogeneity only found acceptable scalability for the euthymia subscale.

LIMITATIONS

A comparison with the Eysenck Neuroticism Scale was not performed.

CONCLUSION

The NEO-PI neuroticism scale contains two subscales consisting of items worded in an opposite direction where only the positive euthymia items have an acceptable scalability.

The treatment of traumatised refugees with sertraline versus venlafaxine in combination with psychotherapy – a randomised clinical study

Background and aim

Today we lack sufficient evidence to conclude which type of treatment approach that is most efficient when it comes to trauma-affected refugees. That is a problem for both patients and doctors as well as for society. Also there is a lack of studies, which examine the relation between psychosocial resources and treatment efficiency, in order to find reliable predictors of treatment outcome. This study therefore aims to produce new evidence within this field in order to optimise treatment for trauma-affected refugees with complex PTSD.

Methods

The study included 207 patients referred to Competence Centre for Transcultural Psychiatry between April 2012 and September 2013. Patients were randomised into one of the two treatment groups: a sertraline group (n = 109) or a venlafaxine group (n = 98). Patients in both groups received the same manual based cognitive behavioural therapy, specially adapted to this group of patients. The trial endpoints were PTSD-and depression symptoms and social functioning, all measured on validated ratings scales. Furthermore the study examined the relation between expected outcome of treatment from a range of predictors and the relation to the treatment results for the individual patient.

Results

Data are presently being analysed and results will be ready for the conference.

Conclusion

The study is among the largest randomised studies ever conducted on pharmacological treatment among traumatised refugees. It is expected to bring forward new knowledge about clinical evaluation and medical treatment of traumatised refugees.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Maintained superiority of chronotherapeutics vs. exercise in a 20-week randomized follow-up trial in major depression

OBJECTIVE

To investigate the long-term antidepressant effect of a chronotherapeutic intervention.

METHOD

In this randomized controlled trial 75 patients with major depression were allocated to fixed duloxetine and either a chronotherapeutic intervention (wake group) with three initial wake therapies, daily bright light therapy, and sleep time stabilization or to a group using daily exercise. Patients were followed 29 weeks. We report the last 20 weeks, a follow-up phase, where medication could be altered. Patients were assessed every 4 weeks. Remission rates were primary outcome.

RESULTS

Patients in the wake group had a statistically significant higher remission rate of 61.9% vs. 37.9% in the exercise group at week 29 (OR = 2.6, CL = 1.3-5.6, P = 0.01). This indicated continued improvement compared with the 9 weeks of treatment response (44.8% vs. 23.4%) with maintenance of the large difference between groups. HAM-D17 endpoint scores were statistically lower in the wake group with endpoint scores of 7.5 (SE = 0.9) vs. 10.1 (SE = 0.9) in the exercise group (difference 2.7, CL = 0.5-4.8, P = 0.02).

CONCLUSION

In this clinical study patients continued to improve in the follow-up phase and obtained very high remission rates. This is the first study to show adjunct short-term wake therapy and long-term bright light therapy as an effective and feasible method to attain and maintain remission.

Comparison of the utility of Cocaine- and Amphetamine-Regulated Transcript (CART), chromogranin A, and chromogranin B in neuroendocrine tumor diagnosis and assessment of disease progression

CONTEXT

Prognosis in patients with neuroendocrine tumors (NETs) is often poor, frequently reflecting delayed diagnosis. Hence, accurate and practical NET markers are needed. Cocaine- and amphetamine-regulated transcript (CART) peptide is a potential novel NET marker.

DESIGN AND PARTICIPANTS

Circulating levels of CART peptide and the established NET markers chromogranin A (CgA) and chromogranin B (CgB) were measured using RIA in 353 patients with NET (normal renal function) and in controls. Clinical data were collected retrospectively.

MAIN OUTCOME MEASURE(S)

The comparative and combined utility of CART, CgA, and CgB for diagnosis and assessment of disease progression was measured in different NET subtypes.

RESULTS

CgA and CgB in combination improved diagnostic accuracy in patients with gut NETs, nongastroenteropancreatic NETs, and NETs with an unknown primary origin compared with each biomarker alone. Measuring CART did not further improve diagnosis in these NET subtypes. For pancreatic NETs, CgB was superior to CgA and CART in detecting stable disease (P < .007), whereas CgA and CART in combination were most effective in identifying progressive disease. In phaeochromocytomas/paragangliomas (PCC/PGL), CART was the most useful biomarker for identifying stable (P < .001) and progressive (P = .001) disease. Consistent with this, plasma CART decreased following PCC/PGL tumor resection, remaining low in all patients in remission, but increasing in those with progressive disease.

CONCLUSIONS

CART is a useful marker for identifying progressive pancreatic NETs. CART is superior to CgA and CgB in detecting stable and progressive PCC/PGLs, and may have a role as a surveillance marker for PCC/PGL patients.

The predictive validity of atypical neurovegetative depressive symptoms identified by the first principal component in the DUAG trial of moclobemide versus clomipramine

OBJECTIVE

To investigate to what extent the primary depression subtype atypical depression can predict differential outcome of the mono-amino-oxidase inhibitor (MAO-I) moclobemide and the tricyclic antidepressant clomipramine in the Danish University Antidepressant Group Study (DUAG).

METHODS

In a randomised, double blind trial, a total of 117 patients with major depression were treated over 6 weeks with either 400 mg moclobemide or 150 mg clomipramine. A baseline principal component analysis (PCA) was performed to identify atypical symptoms on the combined depression scales (Hamilton Depression Scale (HAM-D(17)) and the Quantitative Scale for Atypical Depression (QSAD)). The primary outcome scale was the subscale HAM-D(6) which contains the pure items of depression.

RESULTS

PCA identified two items with loadings opposite to the other depression items within HAM-D(17) and QSAD, namely increased duration of sleep and increased appetite (atypical neurovegetative symptoms). Patients with a positive score at baseline on these items were classified as having atypical depression. In total 13 patients were classified as having atypical depression. Within this group of patients 8 received clomipramine and 5 patients received moclobemide. At endpoint the moclobemide treated patients had a significantly better response than the clomipramine treated (P=0.036), effect size 1.42, when using HAM-D(6) as outcome. However, in the 104 patients classified as having typical depression clomipramine was superior to moclobemide (P=0.034), effect size 0.47.

LIMITATIONS

The number of patients with atypical neurovegetative symptoms was very small and no placebo arm was included.

CONCLUSIONS

It is very important to screen for atypical depression (increased duration of sleep/increased appetite) in the acute therapy of patients with major depression. Our results add to the body of evidence that monoamine oxidase inhibitors are superior to tricyclic antidepressants in this sub-group of patients.

Outcomes on the pharmacopsychometric triangle in bupropion-SR vs. buspirone augmentation of citalopram in the STAR*D trial

OBJECTIVE

To compare within the framework of a novel pharmacopsychometric triangle, augmentation treatment with bupropion vs. buspirone in the acute therapy of major depression in the STAR*D study. The triangle provides a composite view in three domains of antidepressive activity, side effects, and quality of life.

METHOD

Within the pharmacopsychometric triangle, the short six-item subscales of the Hamilton Depression Scale (HAM-D(17)) and of the Inventory of Depressive Symptomatology (IDS-C(30)), referred to as HAM-D(6) and IDS-C(6), were focussed on pure antidepressive effect. Side-effects (tolerable vs. intolerable) and quality of life were measured using patient-administered questionnaires. A modified intention to treat sample was used.

RESULTS

Within the pharmacopsychometric triangle, bupropion-SR (sustained release) was superior to buspirone when augmented to the current citalopram treatment. Thus, in the domain of pure antidepressive effect, bupropion-SR was superior (P = 0.05) on the HAM-D(6), IDS-C(6), and IDS-C(30), but not on the HAM-D(17). In the domain of side effects, the total scores on the Patient Rated Inventory of Side Effects (PRISE) were reduced significantly more by bupropion-SR than by buspirone (P = 0.03). In the domain of quality of life, the total scores on the Quality of Life Enjoyment and Satisfaction Questionnaire (QLES-Q) showed a trend (P = 0.10) from baseline to endpoint of a superiority for bupropion-SR compared with buspirone.

CONCLUSION

In all domains of the pharmacopsychometric triangle, bupropion-SR was superior to buspirone as augmentation therapy in depressed outpatients not responding to citalopram.

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.

Factor structure and dimensionality of the two depression scales in STAR*D using level 1 datasets

BACKGROUND

The factor structure and dimensionality of the HAM-D(17) and the IDS-C(30) are as yet uncertain, because psychometric analyses of these scales have been performed without a clear separation between factor structure profile and dimensionality (total scores being a sufficient statistic).

METHODS

The first treatment step (Level 1) in the STAR*D study provided a dataset of 4041 outpatients with DSM-IV nonpsychotic major depression. The HAM-D(17) and IDS-C(30) were evaluated by principal component analysis (PCA) without rotation. Mokken analysis tested the unidimensionality of the IDS-C(6), which corresponds to the unidimensional HAM-D(6.)

RESULTS

For both the HAM-D(17) and IDS-C(30), PCA identified a bi-directional factor contrasting the depressive symptoms versus the neurovegetative symptoms. The HAM-D(6) and the corresponding IDS-C(6) symptoms all emerged in the depression factor. Both the HAM-D(6) and IDS-C(6) were found to be unidimensional scales, i.e., their total scores are each a sufficient statistic for the measurement of depressive states.

LIMITATIONS

STAR*D used only one medication in Level 1.

CONCLUSIONS

The unidimensional HAM-D(6) and IDS-C(6) should be used when evaluating the pure clinical effect of antidepressive treatment, whereas the multidimensional HAM-D(17) and IDS-C(30) should be considered when selecting antidepressant treatment.

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.

Dose-response relationship of sertindole and haloperidol using the pharmacopsychometric triangle

OBJECTIVE

Renewed insight into dose-related effects of sertindole and haloperidol was sought by re-analysing published data for antipsychotic effect, extrapyramidal effect, and patient wellbeing - i.e., the important pharmacopsychometric triangle domains.

METHOD

Selected Positive and Negative Syndrome Scale (PANSS) subscales and the Simpson-Angus scale were tested for validity. Standardized effect sizes [last observation carried forward (LOCF)] at endpoint were calculated.

RESULTS

The scales were found to be valid instruments. The PANSS(11) psychotic subscale showed clinically significant effect sizes for all doses of sertindole (12, 20, and 24 mg) and haloperidol (4, 8, and 16 mg). Extrapyramidal effects were evident for all doses of haloperidol, but absent for the lower doses of sertindole. The PANSS(6) depression subscale, a proxy measure of quality of life, showed a clinically significant effect for sertindole 20 mg and no effect for haloperidol.

CONCLUSION

This re-analysis confirmed the antipsychotic effect and absence of extrapyramidal effects for sertindole and, in addition, showed a clinically significant antidepressant effect. A profile for bipolar states emerged.

HAM-D17 and HAM-D6 sensitivity to change in relation to desvenlafaxine dose and baseline depression severity in major depressive disorder

INTRODUCTION

This retrospective analysis compared sensitivity to change on the 17-item and 6-item Hamilton Rating Scales For Depression (HAM-D (17) and HAM-D (6), respectively) in relation to antidepressant dose and baseline depression severity.

METHODS

Data were derived from 6 randomized, double-blind, placebo-controlled, 8-week trials of fixed-dose desvenlafaxine (50, 100, 200 or 400 mg/d) for major depressive disorder. HAM-D (17) and HAM-D (6) effect sizes were assessed.

RESULTS

HAM-D (17) effect sizes were negative (favoured placebo) for higher desvenlafaxine doses (200-400 mg/d) at week 1, but were positive for all doses after week 2, with no clear dose-response pattern. However, HAM-D (6) effect sizes were positive for all doses at all weeks. Effect sizes were consistently greater for HAM-D (6) vs. HAM-D (17), regardless of time spent under therapy. Effect sizes were greater for HAM-D (6) vs. HAM-D (17) for all desvenlafaxine doses among patients with baseline HAM-D (17) <25, but not among patients with baseline HAM-D (17) ≥ 25.

DISCUSSION

The HAM-D (6) demonstrated greater sensitivity to change and robustness than the HAM-D (17), supporting the greater homogeneity of the HAM-D (6).

Is the antidepressive effect of second-generation antidepressants a myth?

Two recent meta-analyses on second-generation antidepressants versus placebo in mild to moderate forms of major depression, based on data on all randomized clinical trials using the Hamilton Depression Scale (HAMD) submitted to FDA, have shown an effect size of approximately 0.30 in favour of antidepressants in the acute therapy of major depression. The clinical significance of an effect size at this level was found to be so poor that these meta-analyses have subscribed to the myth of an exclusively placebo-like effect of second-generation antidepressants. A re-allocation of HAMD items focusing on those items measuring severity of clinical depression, the HAMD6, has identified effect sizes of >or=0.40 for second-generation antidepressants in placebo-controlled trials for which even a dose-response relationship can be demonstrated. In the relapse-prevention phase during continuation therapy of patients with major depression, the advantage of second-generation antidepressants over placebo was as significant as in the acute therapy phase. To explore a myth is not to deny the facts but rather to re-allocate them.

Applied psychometrics in clinical psychiatry: the pharmacopsychometric triangle

OBJECTIVE

To consider applied psychometrics in psychiatry as a discipline focusing on pharmacopsychology rather than psychopharmacology as illustrated by the pharmacopsychometric triangle.

METHOD

The pharmacopsychological dimensions of clinically valid effects of drugs (antianxiety, antidepressive, antimanic, and antipsychotic), of clinically unwanted effects of these drugs, and the patients' own subjective perception of the balance between wanted and unwanted effects are analysed using rating scales assessed by modern psychometric tests (item response theory models)

RESULTS

Symptom rating scales fulfilling the item response theory models have been shown to be psychometrically valid outcome scales as their total scores are sufficient statistics for demonstrating dose-response relationship within the various classes of antianxiety, antidepressive, antimanic or antipsychotic drugs. The total scores of side-effect rating scales are, however, not sufficient statistics, implying that each symptom has to be analysed individually. Self-rating scales with very few items appear to be sufficient statistics when measuring the patients' own perception of quality of life.

CONCLUSION

Applied psychometrics in psychiatry have been found to cover a pharmacopsychometric triangle illustrating the measurements of wanted and unwanted effects of pharmacotherapeutic drugs as well as health-related quality of life.

High cortisol awakening response is associated with an impairment of the effect of bright light therapy

OBJECTIVE

We investigated the predictive validity of the cortisol awakening response (CAR) in patients with non-seasonal major depression.

METHOD

Patients were treated with sertraline in combination with bright or dim light therapy for a 5-week period. Saliva cortisol levels were measured in 63 patients, as an awakening profile, before medication and light therapy started. The CAR was calculated by using three time-points: awakening and 20 and 60 min after awakening.

RESULTS

Patients with low CAR had a very substantial effect of bright light therapy compared with dim light therapy, whereas patients with a high CAR had no effect of bright light therapy compared with dim light therapy.

CONCLUSION

High CAR was associated with an impairment of the effect of bright light therapy. This result raises the question of whether bright light acts through a mechanism different from that of antidepressants.

Fifty years with the Hamilton scales for anxiety and depression. A tribute to Max Hamilton

From the moment Max Hamilton started his psychiatric education, he considered psychometrics to be a scientific discipline on a par with biochemistry or pharmacology in clinical research. His clinimetric skills were in operation in the 1950s when randomised clinical trials were established as the method for the evaluation of the clinical effects of psychotropic drugs. Inspired by Eysenck, Hamilton took the long route around factor analysis in order to qualify his scales for anxiety (HAM-A) and depression (HAM-D) as scientific tools. From the moment when, 50 years ago, Hamilton published his first placebo-controlled trial with an experimental anti-anxiety drug, he realized the dialectic problem in using the total score on HAM-A as a sufficient statistic for the measurement of outcome. This dialectic problem has been investigated for more than 50 years with different types of factor analyses without success. Using modern psychometric methods, the solution to this problem is a simple matter of reallocating the Hamilton scale items according to the scientific hypothesis under examination. Hamilton's original intention, to measure the global burden of the symptoms experienced by the patients with affective disorders, is in agreement with the DSM-IV and ICD-10 classification systems. Scale reliability and obtainment of valid information from patients and their relatives were the most important clinimetric innovations to be developed by Hamilton. Max Hamilton therefore belongs to the very exclusive family of eminent physicians celebrated by this journal with a tribute.