Restoring melancholia in the classification of mood disorders

Catatonia and melancholia interface: exploring a new paradigm for evaluation and treatment. A case series and literature review

Background

Catatonia has been increasingly associated with mood disorders and is recognized as a specifier in the DSM-5 and DSM-5-TR. The DSM-5-TR recognizes melancholia as a specifier for depressive episodes in major depressive disorder and bipolar disorder. It is characterized by severe anhedonia, lack of reactivity, excessive or delusional guilt, and significant vegetative symptoms. As the conceptualization of melancholia expanded beyond its mood components to include psychomotor disturbances, its overlap with psychomotor symptoms or catatonia becomes evident. This overlap was also described in Kahlbaum's original literature, where he describes the transition between states of melancholia, mania, and catatonia.

Method

Case summary of six patients with major depressive disorder or depressed phase of bipolar disorder who were admitted for severe depression, anhedonia, intense anxiety, psychomotor agitation or retardation, indecisiveness, perseveration, and vegetative symptoms such as poor sleep, appetite, and significant weight loss.

Results

All patients demonstrated rapid and complete resolution of their mood and psychomotor symptoms, indecisiveness, perseveration, as well as psychosis shortly after administration of lorazepam, with recurrence of the above symptoms upon lorazepam discontinuation and resolution upon resumption, in an on-and-off manner.

Conclusion

The present study argues for a closer relationship between melancholia and catatonia based on our case series, historical review, overlap in phenomenology, and response to treatment. We propose provisional [Mahgoub] criteria for patients with severe depression and melancholia. The role of GABA agonists, such as lorazepam, can be explored as an option for patients with treatment-resistant depression who meet these criteria for melancholia.

Limitations

Absence of a standardized, systematic assessment tool and a small sample size.

Is melancholia a distinct syndrome? Recurrence, chronicity, and severity give evidence in the 50 year follow-up of the Lundby Study

Introduction

Whether melancholia is a distinct syndrome has long been debated. One aspect of a valid syndrome is whether it allows for determination of a prognosis. The aim of this study is to investigate the course of melancholic depression versus non-melancholic depression with a focus on: (i) time to and probability of recovery from the first depressive episode, (ii) time to and risk of the first recurrence, (iii) rate of recurrence, (iv) time with depression or antidepressant medication, and (v) suicide risk.

Methods

The Lundby Study is a longitudinal community study on mental health that followed a geographically defined population (N = 3,563) for up to 50 years, 1947-1997. Subjects with first onset depression were assessed as melancholic (N = 46) or non-melancholic (N = 381) using the DSM-IV melancholic specifier. These diagnoses were made in retrospect using all available information from semi-structured interviews by psychiatrists, key informants, registers, and patient records.

Results

We found no significant difference between melancholic- and non-melancholic depression in time to and probability of recovery from the first depressive episode. The time to first recurrence was shorter in melancholic than in non-melancholic depression and the risk of first recurrence for the melancholic group was 2.77 (95% confidence interval [CI] 1.83-4.20) times the risk in the non-melancholic group. The median rate of recurrence was higher in the melancholic group, at 0.19 recurrences per year at risk (interquartile range [IQR] 0.08-0.47), compared to the non-melancholic group, at 0.10 recurrences per year at risk (IQR 0.05-0.21) (p < 0.03). The median percentage of time being depressed or on antidepressant medication was higher in the melancholic group, 17% (IQR 3-20%), compared to the non-melancholic group, 8% (IQR 7-33%) (p < 0.001). The risk of suicide was higher in the melancholic group, hazard ratio 4.13 (95% CI 1.49-11.48, p < 0.01).

Discussion

To conclude, melancholic depression had a more recurrent, chronic, and severe course with a higher suicide risk than did non-melancholic depression in the Lundby population. Although our use of retrospective diagnosis might limit interpretation of results, the findings indicate that melancholia may be useful in determining prognosis and may be a valid psychopathological syndrome.

Incidence of melancholic depression by age of onset and gender in the Lundby population, 1947-1997

Whether melancholic depression is a distinct syndrome or not has long been debated. There are few studies providing information about the epidemiology of melancholic depression. In this study, we investigate the incidence rates, overall as well as by gender and age of onset of melancholic depression according to Taylor and Fink and corresponding DSM-IV disorders: major depressive disorder (MDD) with melancholic specifier, MDD with psychotic features, MDD with postpartum debut and bipolar depression in the Lundby population. Incidence rates with 95% confidence intervals were calculated. The incidence rate of melancholic depression was 0.48 (CI 0.36-0.61) per 1000 person-years under risk. The rates of the corresponding DSM-IV disorders were as follows: MDD with melancholic specifier 0.38 (CI 0.27-0.49), MDD with psychotic features 0.13 (CI 0.07-0.21), MDD with postpartum debut 0.02 (CI 0.00-0.06) and bipolar depression 0.04 (CI 0.01-0.10). Females had a significantly higher incidence rate, with a peak in age group 40-49, in melancholic depression according to Taylor and Fink and MDD with melancholic specifier. There was no gender difference in incidence rates of MDD with psychotic features or bipolar depression. The diagnoses were set in retrospect and the number of subjects with MDD with postpartum debut and bipolar depression was low. Incidence of melancholia was low in the Lundby Study. There was a female preponderance to become melancholically depressed in line with research on undifferentiated depression.

From Melancholia to Depression: Disordered Mood in Nineteenth-Century Psychiatry

My book From Melancholia to Depression: Disordered Mood in Nineteenth-Century Psychiatry charts how melancholia was reconceptualized in the nineteenth century as a modern mood disorder and a precursor to clinical depression. The book shows how this occurred chiefly in two ways. First, the idea of disordered mood as a medical concept was created through the appropriation of language from experimental physiology into the realm of psychopathology. Second, the interplay of statistical and diagnostic practices formed the basis for modern psychiatric classification and facilitated the standardization of melancholia as a psychiatric diagnosis. These developments were key to the reconceptualization of melancholia and the subsequent emergence of clinical depression, and were foundational to modern psychiatric theory and practice.

Ventral striatal activation during reward differs between major depression with and without impaired mood reactivity

BACKGROUND

Recent efforts to classify subtypes of major depressive disorder marked by different psychophysiological indicators have identified blunted reward-related brain activation in gambling tasks as a characteristic linked specifically to depressed participants with impaired mood reactivity.

METHODS

The current study compared individuals diagnosed with current depressive disorder (n = 26) with healthy controls (n = 24) regarding brain responses to gain and loss trials in an fMRI version of the "Doors" choice-feedback task. Study aims were to examine reward-related brain activation in relation to depression, depressive subtypes, and course of depression.

RESULTS

Across the sample, participants showed a significant response to gain versus loss in left and right ventral striatum as well as medial and left lateral prefrontal cortex. Relative to controls, participants with current depression were characterized by blunted reactivity in left ventral striatum. Furthermore, activation in the left ventral striatum differentiated subgroups of depression with and without impaired mood reactivity. Finally, left striatal hypoactivation to reward predicted remission when controlling for current depressive symptomatology, albeit at a trend level.

CONCLUSIONS

Blunted reward-related activation in the left ventral striatum might be useful as a marker for depression subtype and may have the potential to predict future course of depression.

Melancholic Features in Bipolar Depression and Response to Lamotrigine: A Pooled Analysis of Five Randomized Placebo-Controlled Trials

BACKGROUND

A pilot study suggested lamotrigine may be more effective for bipolar depression with melancholic features. We tested this hypothesis in a pooled analysis of 5 randomized double-blind placebo-controlled trials of lamotrigine for acute bipolar depression.

METHODS

The pooled sample consisted of 1072 adult outpatients. Depressive symptoms were assessed for 7 to 10 weeks with the Hamilton Depression Rating Scale and the Montgomery-Åsberg Depression Rating Scale. The outcome measure was end-trial response (score reduction ≥ 50%). Melancholic features were assessed with both the Structured Clinical Interview for DSM-IV and baseline depression scale items, according to DSM criteria.

RESULTS

The item-based melancholic specifier was associated with numerically larger treatment effects, although subgroup-treatment interactions in logistic regression models did not reach statistical significance. The small subgroup of patients with severe psychomotor retardation also appeared to benefit from lamotrigine. However, the Structured Clinical Interview for DSM-IV melancholic specifier was not associated with larger treatment effects. Baseline depression severity was inconsistently associated with response, depending on which scale was used to define severity. The 2 melancholia variables had poor agreement despite having similar prevalences.

CONCLUSIONS

Our results do not clearly support the original hypothesis but do reinforce the importance of replicating secondary analyses of clinical trials with additional data.

Peripheral Markers of Depression

Major Depressive Disorder (MDD) is a leading cause of disability worldwide, creating a high medical and socioeconomic burden. There is a growing interest in the biological underpinnings of depression, which are reflected by altered levels of biological markers. Among others, enhanced inflammation has been reported in MDD, as reflected by increased concentrations of inflammatory markers-C-reactive protein, interleukin-6, tumor necrosis factor-α and soluble interleukin-2 receptor. Oxidative and nitrosative stress also plays a role in the pathophysiology of MDD. Notably, increased levels of lipid peroxidation markers are characteristic of MDD. Dysregulation of the stress axis, along with increased cortisol levels, have also been reported in MDD. Alterations in growth factors, with a significant decrease in brain-derived neurotrophic factor and an increase in fibroblast growth factor-2 and insulin-like growth factor-1 concentrations have also been found in MDD. Finally, kynurenine metabolites, increased glutamate and decreased total cholesterol also hold promise as reliable biomarkers for MDD. Research in the field of MDD biomarkers is hindered by insufficient understanding of MDD etiopathogenesis, substantial heterogeneity of the disorder, common co-morbidities and low specificity of biomarkers. The construction of biomarker panels and their evaluation with use of new technologies may have the potential to overcome the above mentioned obstacles.

Melancholic depression and response to quetiapine: A pooled analysis of four randomized placebo-controlled trials

BACKGROUND

Melancholic depression may preferentially respond to certain treatments. This study examined the efficacy of extended-release quetiapine monotherapy in patients with melancholic and nonmelancholic major depressive disorder.

METHODS

Data from four randomized placebo-controlled trials was pooled. Melancholic features were assessed with baseline depression scale items according to DSM criteria. The outcome measure was response on the Montgomery-Åsberg Depression Rating Scale. Cox regression models predicting response over time with interactions between treatment condition and melancholic status were used to test for treatment effect heterogeneity.

RESULTS

The 6-week response rate difference between quetiapine and placebo was roughly 10% greater in the melancholic subgroup, primarily due to a lower placebo response, although the subgroup-treatment interactions did not reach statistical significance. The main effect of quetiapine was significant in every model.

LIMITATIONS

The main limitations were the retrospective analysis and the post-hoc designation of melancholic depression based on scale items not designed for that purpose. Results should be considered preliminary and exploratory until replicated.

CONCLUSIONS

The lower placebo response rate in the melancholic subgroup is consistent with past research and reinforces the benefit of pharmacotherapy for these patients.

The clinical characterization of the adult patient with depression aimed at personalization of management

Depression is widely acknowledged to be a heterogeneous entity, and the need to further characterize the individual patient who has received this diagnosis in order to personalize the management plan has been repeatedly emphasized. However, the research evidence that should guide this personalization is at present fragmentary, and the selection of treatment is usually based on the clinician's and/or the patient's preference and on safety issues, in a trial-and-error fashion, paying little attention to the particular features of the specific case. This may be one of the reasons why the majority of patients with a diagnosis of depression do not achieve remission with the first treatment they receive. The predominant pessimism about the actual feasibility of the personalization of treatment of depression in routine clinical practice has recently been tempered by some secondary analyses of databases from clinical trials, using approaches such as individual patient data meta-analysis and machine learning, which indicate that some variables may indeed contribute to the identification of patients who are likely to respond differently to various antidepressant drugs or to antidepressant medication vs. specific psychotherapies. The need to develop decision support tools guiding the personalization of treatment of depression has been recently reaffirmed, and the point made that these tools should be developed through large observational studies using a comprehensive battery of self-report and clinical measures. The present paper aims to describe systematically the salient domains that should be considered in this effort to personalize depression treatment. For each domain, the available research evidence is summarized, and the relevant assessment instruments are reviewed, with special attention to their suitability for use in routine clinical practice, also in view of their possible inclusion in the above-mentioned comprehensive battery of measures. The main unmet needs that research should address in this area are emphasized. Where the available evidence allows providing the clinician with specific advice that can already be used today to make the management of depression more personalized, this advice is highlighted. Indeed, some sections of the paper, such as those on neurocognition and on physical comorbidities, indicate that the modern management of depression is becoming increasingly complex, with several components other than simply the choice of an antidepressant and/or a psychotherapy, some of which can already be reliably personalized.

Predicting SSRI-Resistance: Clinical Features and tagSNPs Prediction Models Based on Support Vector Machine

BACKGROUND

A large proportion of major depressive patients will experience recurring episodes. Many patients still do not response to available antidepressants. In order to meaningfully predict who will not respond to which antidepressant, it may be necessary to combine multiple biomarkers and clinical variables.

METHODS

Eight hundred fifty-seven patients with recurrent major depressive disorder who were followed up 3-10 years involved 32 variables including socio-demographic, clinical features, and SSRIs treatment features when they received the first treatment. Also, 34 tagSNPs related to 5-HT signaling pathway, were detected by using mass spectrometry analysis. The training samples which had 12 clinical variables and four tagSNPs with statistical differences were learned repeatedly to establish prediction models based on support vector machine (SVM).

RESULTS

Twelve clinical features (psychomotor retardation, psychotic symptoms, suicidality, weight loss, SSRIs average dose, first-course treatment response, sleep disturbance, residual symptoms, personality, onset age, frequency of episode, and duration) were found significantly difference (P< 0.05) between 302 SSRI-resistance and 304 SSRI non-resistance group. Ten SSRI-resistance predicting models were finally selected by using support vector machine, and our study found that mutations in tagSNPs increased the accuracy of these models to a certain degree.

CONCLUSION

Using a data-driven machine learning method, we found 10 predictive models by mining existing clinical data, which might enable prospective identification of patients who are likely to resistance to SSRIs antidepressant.

Validation of a Psychosocial Chronic Stress Model in the Pig Using a Multidisciplinary Approach at the Gut-Brain and Behavior Levels

Psychological chronic stress is an important risk factor for major depressive disorder, of which consequences have been widely studied in rodent models. This work aimed at describing a pig model of chronic stress based on social isolation, environmental impoverishment and unpredictability. Three groups of animals of both sexes were constituted. Two were exposed to the psychosocial stressors while receiving (SF, n = 12) or not (SC, n = 22) the antidepressant fluoxetine, and a third group (NSC, n = 22) remained unstressed. Animals were observed in home pens and during dedicated tests to assess resignation and anxiety-like behaviors. Brain structure and function were evaluated via proton MRS and fMRI. Hippocampal molecular biology and immunodetection of cellular proliferation (Ki67⁺) and neuron maturation (DCX⁺) in the dentate gyrus were also performed. Salivary cortisol, fecal short-chain fatty acids (SCFAs), and various plasmatic and intestinal biomarkers were analyzed. Compared to NSC, SC animals showed more resignation (p = 0.019) and had a higher level of salivary cortisol (p = 0.020). SC brain responses to stimulation by a novel odor were lower, similarly to their hippocampal neuronal density (p = 0.015), cellular proliferation (p = 0.030), and hippocampal levels of BDNF and 5-HT_1AR (p = 0.056 and p = 0.007, respectively). However, the number of DCX⁺ cells was higher in the ventral dentate gyrus in this group (p = 0.025). In addition, HOMA-IR was also higher (p < 0.001) and microbiota fermentation activity was lower (SCFAs, SC/NSC: p < 0.01) in SC animals. Fluoxetine partially or totally reversed several of these effects. Exposure to psychosocial stressors in the pig model induced effects consistent with the human and rodent literature, including resignation behavior and alterations of the HPA axis and hippocampus. This model opens the way to innovative translational research exploring the mechanisms of chronic stress and testing intervention strategies with good face validity related to human.

Impact, Diagnosis, Phenomenology, and Biology

This section provides summaries of the epidemiology, phenomenology, nosology, and the suspected biological substrates of the depressive disorders. It particularly emphasizes the historical evolution of the pertinent diagnostic constructs and the prognostic import both of the various diagnostic groupings and of the individual symptoms and symptom clusters.

Lower levels of brain-derived neurotrophic factor are associated with melancholic psychomotor retardation among depressed inpatients

OBJECTIVES

Melancholic depression is a type of depression which is closely related to biological variables than are other types of depression. Its clinical features can be assessed using six items on the Hamilton Depression Rating Scale (HAM-D₆ ). Previous studies have shown, using item response theory, that the symptom depressed mood is the least severe melancholic feature; work and activities, somatic symptoms and psychic anxiety are of moderate severity; and feelings of guilt and psychomotor retardation are the most severe. We aimed to evaluate whether the more severe melancholic signs or symptoms were associated with decreases in brain-derived neurotrophic factor (BDNF) levels.

METHODS

A total of 151 severely depressed inpatients had their BDNF levels analyzed by comparing those who presented with each HAM-D₆ melancholic feature to those for whom the HAM-D₆ feature was absent, using multiple linear regressions. The levels of BDNF of patients who presented with each melancholic feature were also compared with those of 100 healthy controls.

RESULTS

Depressed patients' median BDNF level was 44.06 ng/mL (interquartile range [IQR]: 33.99-62.4 ng/mL), and controls' median BDNF level was 65.22 ng/mL (IQR: 49.87-76.08 ng/mL) (P < .001). The presence of depressed mood, work and activities, somatic symptoms, psychic anxiety, and guilty feelings was not associated with BDNF levels. However, the presence of psychomotor retardation was associated with reduced BDNF (median reduction -10.07 ng/mL; 95% confidence interval [CI]: -19.43 to -0.71; P = .03).

CONCLUSIONS

To the best of our knowledge, this study is the first to associate BDNF levels with melancholic features in a sample of severely depressed inpatients. The main finding of this study was that severely depressed inpatients who presented the most severe melancholic feature, psychomotor retardation, had significantly reduced BDNF levels in the blood.

Depression

Major depression is a common illness that severely limits psychosocial functioning and diminishes quality of life. In 2008, WHO ranked major depression as the third cause of burden of disease worldwide and projected that the disease will rank first by 2030.¹ In practice, its detection, diagnosis, and management often pose challenges for clinicians because of its various presentations, unpredictable course and prognosis, and variable response to treatment.

Rethinking IL-6 and CRP: Why they are more than inflammatory biomarkers, and why it matters

Behavioral researchers have increasingly become interested in the idea that chronic, low-grade inflammation is a pathway through which social and behavioral variables exert long-term effects on health. Much research in the area employs putative inflammatory biomarkers to infer an underlying state of inflammation. Interleukin 6 (IL-6) and C-reactive protein (CRP, whose production is stimulated by IL-6) are arguably the two most commonly assayed biomarkers. Yet, in contrast with near-universal assumptions in the field, discoveries in immunology over the past two decades show that neither IL-6 nor CRP are unambiguous inflammatory markers. IL-6 operates through two distinct signaling pathways, only one of which is specifically upregulated during inflammation; both pathways have a complex range of effects and influence multiple physiological processes even in absence of inflammation. Similarly, CRP has two isoforms, one of which is produced locally in inflamed or damaged tissues. The other isoform is routinely produced in absence of inflammation and may have net anti-inflammatory effects. We propose a functional framework to account for the multiple actions of IL-6 and CRP. Specifically, we argue that both molecules participate in somatic maintenance efforts; hence elevated levels indicate that an organism is investing in protection, preservation, and/or repair of somatic tissue. Depending on the state of the organism, maintenance may be channeled into resistance against pathogens (including inflammation), pathogen tolerance and harm reduction, or tissue repair. The findings and framework we present have a range of potential implications for the interpretation of empirical findings in this area-a point we illustrate with alternative interpretations of research on socioeconomic status, stress, and depression.

The dose makes the poison: from glutamate-mediated neurogenesis to neuronal atrophy and depression

Experimental evidence has demonstrated that glutamate is an essential factor for neurogenesis, whereas another line of research postulates that excessive glutamatergic neurotransmission is associated with the pathogenesis of depression. The present review shows that such paradox can be explained within the framework of hormesis, defined as biphasic dose responses. Low glutamate levels activate adaptive stress responses that include proteins that protect neurons against more severe stress. Conversely, abnormally high levels of glutamate, resulting from increased release and/or decreased removal, cause neuronal atrophy and depression. The dysregulation of the glutamatergic transmission in depression could be underlined by several factors including a decreased inhibition (γ-aminobutyric acid or serotonin) or an increased excitation (primarily within the glutamatergic system). Experimental evidence shows that the activation of N-methyl-D-aspartate receptor (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors (AMPAR) can exert two opposite effects on neurogenesis and neuron survival depending on the synaptic or extrasynaptic concentration. Chronic stress, which usually underlies experimental and clinical depression, enhances glutamate release. This overactivates NMDA receptors (NMDAR) and consequently impairs AMPAR activity. Various studies show that treatment with antidepressants decreases plasma glutamate levels in depressed individuals and regulates glutamate receptors by reducing NMDAR function by decreasing the expression of its subunits and by potentiating AMPAR-mediated transmission. Additionally, it has been shown that chronic treatment with antidepressants having divergent mechanisms of action (including tricyclics, selective serotonin reuptake inhibitors, and ketamine) markedly reduced depolarization-evoked glutamate release in the hippocampus. These data, taken together, suggest that the glutamatergic system could be a final common pathway for antidepressant treatments.

Depression with melancholic features is associated with higher long-term risk for dementia

BACKGROUND

Depression has been reported to increase the risk of subsequently developing dementia, but the nature of this relation remains to be elucidated. Depression can be a prodrome/manifestation of dementia or an early risk factor, and the effect may differ according to depression subtypes. Our aim was to study the association between early-onset depression and different depression subtypes, and the later occurrence of dementia.

METHODS

We conducted a cohort study including 322 subjects with depression, recruited between 1977 and 1984. A comparison cohort (non-exposed) was recruited retrospectively, to include 322 subjects admitted at the same hospital for routine surgery (appendicectomy or cholecystectomy), at the same period as the depressed cohort. Subjects were contacted again between 2009 and 2014, to assess their dementia status. We computed the risk for dementia in subjects with early onset depression and quantified the association between different depression subtypes (namely melancholic, anxious, and psychotic) and dementia.

RESULTS

The odds of dementia were increased by 2.90 times (95% C.I. 1.61-5.21; p<0.0001) for the depressed cohort when compared to the surgical cohort. When the analysis was restricted to patients younger than 45 years old at baseline, the odds for dementia in the depressed cohort were also significantly higher when compared to the surgical cohort (8.53; 95% C.I. 2.40-30.16). In the multivariate Cox analysis, subjects having depression with melancholic features had an increased risk for developing dementia compared to those without melancholic features (HR=3.64; 95% C.I. 1.78-11.26; p=0.025).

LIMITATIONS

About 59% of the participants with depression and 53% of those non-exposed were lost during follow up. The inclusion of biological biomarkers would strengthen the results. The sample included a low number of bipolar patients.

CONCLUSIONS

These results support depression as an early risk factor for dementia. Depression with melancholic features was found as an important risk factor for dementia, playing a main role in the relation between these disorders.

A meta-analysis of cognitive performance in melancholic versus non-melancholic unipolar depression

BACKGROUND

Recently there is increasing recognition of cognitive dysfunction as a core feature of Major Depressive Disorder (MDD). The goal of the current meta-analysis was to review and examine in detail the specific features of cognitive dysfunction in Melancholic (MEL) versus Non-Melancholic (NMEL) MDD.

METHODS

An electronic literature search was performed to find studies comparing cognitive performance in MEL versus NMEL. A meta-analysis of broad cognitive domains (processing speed, reasoning/problem solving, verbal learning, visual learning, attention/working memory) was conducted on all included studies (n=9). Sensitivity and meta-regression analyses were also conducted to detect possible effects of moderator variables (age, gender, education, symptom severity and presence of treatments).

RESULTS

MEL patients were older and more severly depressed than NMEL subjects. The MEL group was characterized by a worse cognitive performance in attention/working memory (ES=-0.31), visual learning (ES=-0.35) and reasoning/problem solving (ES=-0.46). No difference was detected in drug-free patients by sensitivity analyses. No effect was found for any of our moderators on the cognitive performance in MEL vs NMEL.

CONCLUSION

Our findings seem to support a moderate but specific effect of melancholic features in affecting the cognitive performance of MDD, in particular as regards visual learning and executive functions.

Anticipatory reward deficits in melancholia

Dysfunctional reward processing has long been considered an important feature of major depressive disorder (MDD). However, depression is a heterogeneous construct and the nature of this heterogeneity may contribute to some of the inconsistent empirical findings on reward dysfunction in MDD. The current study examined 1 source of heterogeneity, melancholic symptoms, and its association with reward processing. In individuals with MDD (N = 141) and MDD-free controls (N = 113), electroencephalogram (EEG) alpha asymmetry was measured during a behavioral reward task that probed reward anticipation. Melancholic depression was measured both categorically (Diagnostic and Statistical Manual of Mental Disorders [DSM] diagnosis) and dimensionally (Hamilton Endogenomorphy Scale [HES]). Results showed that a dimensional (and not categorical) definition of melancholia predicted reward processing, with higher melancholic symptoms predicting reduced reward anticipation. Importantly, the effects of melancholic symptoms on reduced reward anticipation remained above and beyond overall depression severity. These results suggest that dysfunctional reward processing may only be associated with melancholic symptoms, not depression in general. (PsycINFO Database Record

Feelings of worthlessness during a single complicated major depressive episode predict postremission suicide attempt

OBJECTIVE

To establish which symptoms of major depressive episode (MDE) predict postremission suicide attempts in complicated single-episode cases.

METHOD

Using the nationally representative two-wave National Epidemiologic Survey on Alcohol and Related Conditions data set, we identified wave 1 lifetime single-episode MDE cases in which the episode remitted by the beginning of the wave 2 three-year follow-up period (N = 2791). The analytic sample was further limited to 'complicated' cases (N = 1872) known to have elevated suicide attempt rates, defined as having two or more of the following: suicidal ideation, marked role impairment, feeling worthless, psychomotor retardation, and prolonged (>6 months) duration.

RESULTS

Logistic regression analyses showed that, after controlling for wave 1 suicide attempt which significantly predicted postremission suicide attempt (OR = 10.0), the additional complicated symptom 'feelings of worthlessness' during the wave 1 index episode significantly and very substantially predicted postremission suicide attempt (OR = 6.96). Neither wave 1 psychomotor retardation nor wave 1 suicidal ideation nor any of the other wave 1 depressive symptoms were significant predictors of wave 2 suicide attempt.

CONCLUSION

Among depressive symptoms during an MDE, feelings of worthlessness is the only significant indicator of elevated risk of suicide attempt after the episode has remitted, beyond previous suicide attempts.

Anhedonia in melancholic and non-melancholic depressive disorders

BACKGROUND

Anhedonia represents a core symptom of major depression and may be a potential marker for melancholia. However, current understanding of this construct in depressive sub-types is limited.

METHOD

Participants were recruited from the Black Dog Institute (Sydney) and Massachusetts General Hospital (Boston). Diagnostic groups were derived on the basis of agreement between clinician and DSM-IV diagnosis from structured interviews. Currently depressed unipolar melancholic, non-melancholic and healthy control participants were administered a probabilistic reward task (PRT) to assess a behavioural correlate of anhedonia-blunted reward-based learning. Self-reported measures of anhedonia, approach and avoidance motivation were completed by the Sydney sample.

RESULTS

Relative to healthy controls and non-melancholic participants, melancholic depressed participants had reduced response bias, highlighting blunted reward learning. Moreover, although non-melancholic participants were characterized by a delayed response bias, melancholic depressed participants failed to develop a bias throughout blocks. Response bias showed no associations with self-report measures of hedonic tone in depressed participants. Positive associations were observed between response bias, approach and avoidance motivation in non-melancholic participants only.

LIMITATIONS

Possible medication, fatigue and anxiety effects were not controlled; small sample sizes; inclusion criteria may have excluded those with severe melancholia and led to underestimation of group differences.

CONCLUSIONS

Melancholia is characterised by a reduced ability to modulate behaviour as a function of reward, and the motivational salience of rewarding stimuli may differ across depressive sub-types. Results support the view that melancholia is a distinct sub-type. Further exploration of reward system functioning in depressive sub-types is warranted.

Distinguishing between emotional distress and psychiatric disorder in primary care attenders: A cross sectional study of the four-dimensional symptom questionnaire (4DSQ)

BACKGROUND

Detection of psychiatric disorder in primary care is a complex issue. Distinctions between 'normal' emotional distress and psychiatric disorder depend on how disorder is conceptualized. Our aim was to explore two different conceptualizations by examining patients' scores on one-dimensional depression measures and scores on the Four Dimensional Symptom Questionnaire (4DSQ), a measure that uniquely has separate dimensions for general distress and depressive disorder.

METHODS

This was a cross sectional study of 487 primary care patients attending general clinics in Hampshire, UK. Patients completed the 4DSQ, Patient Health Questionnaire-9 (PHQ-9), General Health Questionnaire-12 (GHQ-12) and the Hospital Anxiety and Depression Scale (HADS) whilst in the waiting room.

RESULTS

The 4DSQ classified 26% (126/485) of patients as having heightened distress levels and 8% (38/468) as possible cases of depressive disorder. Casesness was consistently higher across the one-dimensional measures (PHQ-9: 16%, GHQ-12: 28%, HADS-D: 13%). Of those patients deemed possible cases by the PHQ-9 (≥ 10), the 4DSQ classified 91% (71/78) as having heightened distress and 44% (32/72) as possible cases of depressive disorder.

LIMITATIONS

The sample was predominately older and white, which may limit generalizability of the findings to more diverse patient groups. There are limits to self-report measures in the assessment of complex diagnostic issues.

CONCLUSIONS

Inclusion of a distinct general distress dimension alongside a dimension focusing on specific depression symptomatology lowered the number of primary care patients classified as possible cases of disorder. This view of symptoms may have implications for the targeting of existing treatments, and may be useful in guiding the development of novel self-management interventions.

Corticosterone mediates the synaptic and behavioral effects of chronic stress at rat hippocampal temporoammonic synapses

Chronic stress is thought to impart risk for depression via alterations in brain structure and function, but contributions of specific mediators in generating these changes remain unclear. We test the hypothesis that stress-induced increases in corticosterone (CORT), the primary rodent glucocorticoid, are the key mediator of stress-induced depressive-like behavioral changes and synaptic dysfunction in the rat hippocampus. In rats, we correlated changes in cognitive and affective behavioral tasks (spatial memory consolidation, anhedonia, and neohypophagia) with impaired excitatory strength at temporoammonic-CA1 (TA-CA1) synapses, an archetypical stress-sensitive excitatory synapse. We tested whether elevated CORT was sufficient and necessary to generate a depressive-like behavioral phenotype and decreased excitatory signaling observed at TA-CA1 after chronic unpredictable stress (CUS). Chronic CORT administration induced an anhedonia-like behavioral state and neohypophagic behavior. Like CUS, chronic, but not acute, CORT generated an impaired synaptic phenotype characterized by reduced α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-preferring glutamate receptor-mediated excitation at TA-CA1 synapses, decreased AMPA-type glutamate receptor subunit 1 protein expression, and altered serotonin-1B receptor-mediated potentiation. Repeatedly blunting stress-induced increases of CORT during CUS with the CORT synthesis inhibitor metyrapone (MET) prevented these stress-induced neurobehavioral changes. MET also prevented the CUS-induced impairment of spatial memory consolidation. We conclude that corticosterone is sufficient and necessary to mediate glutamatergic dysfunction underlying stress-induced synaptic and behavioral phenotypes. Our results indicate that chronic excessive glucocorticoids cause specific synaptic deficits in the hippocampus, a major center for cognitive and emotional processing, that accompany stress-induced behavioral dysfunction. Maintaining excitatory strength at stress-sensitive synapses at key loci throughout corticomesolimbic reward circuitry appears critical for maintaining normal cognitive and emotional behavior.

An adaptationist perspective on the etiology of depression

Major depressive disorder (MDD) presents with a variety of symptoms and responds to a wide range of treatment interventions. Diagnostic criteria collapse multiple syndromes with distinct etiologies into the same disorder. MDD is typically understood as a malfunction of neurotransmission or brain circuitry regulating mood, pleasure and reward, or executive function. However, research from an evolutionary perspective suggests that the "normal" functioning of adaptations may also generate symptoms meeting diagnostic criteria. Functioning adaptations may be an underappreciated etiological pathway to MDD. Many adaptive functions for depressive symptoms have been suggested: biasing cognition to avoid losses, conserving energy, disengaging from unobtainable goals, signaling submission, soliciting resources, and promoting analytical thinking. We review the potential role of these adaptive functions and how they can lead to specific clusters of depressive symptoms. Understanding MDD from such a perspective reduces the heterogeneity of cases and may help to select the best intervention for each patient. We discuss the implications of different adaptive and maladaptive etiological pathways for the use of antidepressants and various modes of psychotherapy. In particular, instances of MDD caused by functioning adaptations may benefit most from treatments that support the adaptive function, or that target the precipitating causal stressor. We conclude that an evolutionary approach to the study of MDD may be one of the more promising approaches to reduce its heterogeneity and to better match patients and treatment.

Dimensions in major depressive disorder and their relevance for treatment outcome

BACKGROUND

Major depressive disorder (MDD) is a heterogeneous disease. More homogeneous psycho(patho)logical dimensions would facilitate MDD research as well as clinical practice. The first aim of this study was to find potential dimensions within a broad psychopathological assessment in depressed patients. Second, we aimed at examining how these dimensions predicted course in MDD.

METHODS

Ten psychopathological variables were assessed in 75 MDD inpatients. Factor and regression analyses assessed putative relations between psychopathological factors and depression severity and outcome after 8 weeks of treatment.

RESULTS

A 3-factor model (eigenvalue: 54.4%) was found, representing a psychomotor change, anhedonia and negative affect factor. Anhedonia and negative affect predicted depression severity (R(2)=0.37, F=20.86, p<0.0001). Anhedonia predicted non-response (OR 6.00, CI 1.46-24.59) and both negative affect (OR 5.69, CI 1.19-27.20) and anhedonia predicted non-remission (OR 9.28, CI 1.85-46.51).

LIMITATIONS

The sample size of the study was relatively modest, limiting the number of variables included in the analysis.

CONCLUSIONS

Results confirm that psychomotor change, anhedonia and negative affect are key MDD dimensions, two of which are related to treatment outcome.

Pharmacological management of unipolar depression

OBJECTIVE

To be used in conjunction with 'Psychological management of unipolar depression' [Lampe et al. Acta Psychiatr Scand 2013;127(Suppl. 443):24-37] and 'Lifestyle management of unipolar depression' [Berk et al. Acta Psychiatr Scand 2013;127(Suppl. 443):38-54]. To provide clinically relevant recommendations for the use of pharmacological treatments in depression derived from a literature review.

METHOD

Using our previous Clinical Practice Guidelines [Malhi et al. Clinical practice recommendations for bipolar disorder. Acta Psychiatr Scand 2009;119(Suppl. 439):27-46] as a foundation, these clinician guidelines target key practical considerations when prescribing pharmacotherapy. A comprehensive review of the literature was conducted using electronic database searches (PubMed, MEDLINE), and the findings have been synthesized and integrated alongside clinical experience.

RESULTS

The pharmacotherapy of depression is an iterative process that often results in partial and non-response. Beyond the initiation of antidepressants, the options within widely used strategies, such as combining agents and switching between agents, are difficult to prescribe because of the paucity of pertinent research. However, there is some evidence for second-line strategies, and a non-prescriptive algorithm can be derived that is based broadly on principles rather than specific steps.

CONCLUSION

Depression is by its very nature a heterogeneous illness that is consequently difficult to treat. Invariably, situation-specific factors often play a significant role and must be considered, especially in the case of partial and non-response. Consulting with colleagues and trialling alternate treatment paradigms are essential strategies in the management of depression.

DSM-5: a collection of psychiatrist views on the changes, controversies, and future directions

The recent release of the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) by the American Psychiatric Association has led to much debate. For this forum article, we asked BMC Medicine Editorial Board members who are experts in the field of psychiatry to discuss their personal views on how the changes in DSM-5 might affect clinical practice in their specific areas of psychiatric medicine. This article discusses the influence the DSM-5 may have on the diagnosis and treatment of autism, trauma-related and stressor-related disorders, obsessive-compulsive and related disorders, mood disorders (including major depression and bipolar disorders), and schizophrenia spectrum disorders.

Melancholic features and hostility are associated with suicidality risk in Asian patients with major depressive disorder

BACKGROUND

Suicide rates are higher in East-Asians than other populations, and especially high in Koreans. However, little is known about suicidality risk and melancholic features in Asian patients with major depressive disorder (MDD).

METHOD

Drug-free MDD outpatients were included from 13 centers across five ethnicities consisting of Chinese (n=290), Korean (n=101), Thai (n=102), Indian (n=27), and Malay (n=27). All were interviewed using the Mini-International Neuropsychiatric Interview (M.I.N.I.), the Montgomery-Åsberg Depression Rating Scale (MADRS), and the Symptoms Checklist 90-Revised (SCL-90-R).

RESULTS

Of 547 subjects, 177 MDD patients showed melancholic features (32.4%). These melancholic MDD patients revealed significantly higher suicidality risk (p<0.0001), hostility (p=0.037), and severity of depression (p<0.0001) than those MDD patients without melancholic features. Suicidality risk was significantly higher in MDD with melancholic features than those without in subjects with lower hostility, whereas it showed no difference in higher hostility. Adjusted odds ratios of melancholic features and hostility for moderate to high suicidality risk were 1.79 (95% CI=1.15-2.79) and 2.45 (95% CI=1.37-4.38), after adjusting for age, sex, education years, and depression severity. Post-hoc analyses showed that suicidality risk was higher in Korean and Chinese than that of Thai, Indian and Malay in MDD subjects with melancholic features, although depression severity showed no significant differences among the ethnicities.

CONCLUSIONS

Suicidality risk is associated with both melancholic features and hostility and it shows cross-ethnic differences in Asian MDD patients, independent of depression severity.

Rediscovering catatonia: the biography of a treatable syndrome

OBJECTIVE

Catatonia, a disorder of movement and mood, was described and named in 1874. Other observers quickly made the same recognition. By the turn of the century, however, catatonia was incorporated as a type within a conjured syndrome of schizophrenia. There, catatonia has lain in the psychiatric classification for more than a century.

METHOD

We review the history of catatonia and its present status. In the 1970s, the tie was questioned when catatonia was recognized among those with mood disorders. The recognition of catatonia within the neuroleptic malignant syndrome offered effective treatments of high doses of benzodiazepines and electroconvulsive therapy (ECT), again questioning the tie. A verifying test for catatonia (the lorazepam sedation test) was developed. Soon the syndromes of delirious mania, toxic serotonin syndrome, and the repetitive behaviors in adolescents with autism were recognized as treatable variations of catatonia.

RESULTS

Ongoing studies now recognize catatonia among patients labeled as suffering from the Gilles de la Tourette's syndrome, anti-NMDAR encephalitis, obsessive-compulsive disease, and various mutisms.

CONCLUSION

Applying the treatments for catatonia to patients with these syndromes offers opportunities for clinical relief. Catatonia is a recognizable and effectively treatable neuropsychiatric syndrome. It has many faces. It warrants recognition outside schizophrenia in the psychiatric disease classification.

The 5-HT deficiency theory of depression: perspectives from a naturalistic 5-HT deficiency model, the tryptophan hydroxylase 2Arg439His knockin mouse

A decreased level of brain 5-hydroxytryptamine (5-HT) has been theorized to be a core pathogenic factor in depression for half a century. The theory arose from clinical observations that drugs enhancing extracellular levels of 5-HT (5-HT(Ext)) have antidepressant effects in many patients. However, whether such drugs indeed correct a primary deficit remains unresolved. Still, a number of anomalies in putative biomarkers of central 5-HT function have been repeatedly reported in depression patients over the past 40 years, collectively indicating that 5-HT deficiency could be present in depression, particularly in severely ill and/or suicidal patients. This body of literature on putative 5-HT biomarker anomalies and depression has recently been corroborated by data demonstrating that such anomalies indeed occur consequent to severely reduced 5-HT(Ext) levels in a mouse model of naturalistic 5-HT deficiency, the tryptophan hydroxylase 2 His(439) knockin (Tph2KI) mouse. In this review, we will critically assess the evidence for 5-HT deficiency in depression and the possible role of polymorphisms in the Tph2 gene as a causal factor in 5-HT deficiency, the latter investigated from a clinical as well as preclinical angle.

A nosological review of depressive disorders based on observations in clinical practice, part 1: Terminology and phenomenology

OBJECTIVE

The purpose of this paper is to describe the problems with the contemporary nosology of 'depression' and to discuss the key linguistic and phenomenological aspects that are essential prerequisites for a clinically meaningful typology of depressive disorders. The paper comprises observations and reflections drawn from clinical work.

CONCLUSIONS

First, the use of the unqualified, stock term 'depression' is counterproductive, as are the diagnostic non-entities of 'major depression' and 'dysthymia'. Second, the core psychopathology in melancholic depression is a loss of self-confidence, which helps explain the frequent co-occurrence of 'anxiety' with 'depression'. Third, descriptive, non-technical terms such as 'demoralisation' and 'grief' are most helpful in formulating non-melancholic forms of depression and thus useful in differential diagnosis.

Meta-review of depressive subtyping models

BACKGROUND

Increasing dissatisfaction with the non-specificity of major depression has led many to propose more specific depressive subtyping models. The present meta-review seeks to map dominant depressive subtype models, and highlight definitions and overlaps.

METHODS

A database search in Medline and EMBASE of proposed depressive subtypes, and limited to reviews published between 2000 and 2011, was undertaken. Of the more than four thousand reviews, 754 were judged as potentially relevant and provided the base for the present selective meta-review.

RESULTS

Fifteen subtype models were identified. The subtypes could be divided into five molar categories of (1) symptom-based subtypes, such as melancholia, psychotic depression, atypical depression and anxious depression, (2) aetiologically-based subtypes, exemplified by adjustment disorders, early trauma depression, reproductive depression, perinatal depression, organic depression and drug-induced depression, (3) time of onset-based subtypes, as illustrated by early and late onset depression, as well as seasonal affective disorder, (4) gender-based (e.g. female) depression, and (5) treatment resistant depression. An overview considering definition, bio-psycho-social correlates and the evidence base of treatment options for each subtype is provided.

LIMITATIONS

Despite the large data base, this meta-review is nevertheless narrative focused.

CONCLUSIONS

Subtyping depression is a promising attempt to overcome the non-specificity of many diagnostic constructs such as major depression, both in relation to their intrinsic non-specificity and failure to provide treatment-specific information. If a subtyping model is to be advanced it would need, however, to demonstrate differential impacts of causes and treatments.

Demographic and clinical features and prescribing patterns of psychotropic medications in patients with the melancholic subtype of major depressive disorder in China

Background

Little has been known about the demographic and clinical features of the melancholic subtype of major depressive disorder (MDD) in Chinese patients. This study examined the frequency of melancholia in Chinese MDD patients and explored its demographic and clinical correlates and prescribing patterns of psychotropic drugs.

Methods

A consecutively collected sample of 1,178 patients with MDD were examined in 13 psychiatric hospitals or psychiatric units of general hospitals in China nationwide. The cross-sectional data of patients’ demographic and clinical characteristics and prescriptions of psychotropic drugs were recorded using a standardized protocol and data collection procedure. The diagnosis of the melancholic subtype was established using the Mini International Neuropsychiatric Interview (MINI). Medications ascertained included antidepressants, mood stabilizers, antipsychotics and benzodiazepines.

Results

Six hundred and twenty nine (53.4%) of the 1,178 patients fulfilled criteria for melancholia. In multiple logistic regression analyses, compared to non-melancholic counterparts, melancholic MDD patients were more likely to be male and receive benzodiazepines, had more frequent suicide ideations and attempts and seasonal depressive episodes, while they were less likely to be employed and receive antidepressants and had less family history of psychiatric disorders and lifetime depressive episodes.

Conclusions

The demographic and clinical features of melancholic MDD in Chinese patients were not entirely consistent with those found in Western populations. Compared to non-melancholic MDD patients, melancholic patients presented with different demographic and clinical features, which have implications for treatment decisions.

A comparison of melancholic and nonmelancholic recurrent major depression in Han Chinese women

BACKGROUND

Although the diagnosis of melancholia has had a long history, the validity of the current DSM-IV definition remains contentious. We report here the first detailed comparison of melancholic and nonmelancholic major depression (MD) in a Chinese population examining in particular whether these two forms of MD differ quantitatively or qualitatively.

METHODS

DSM-IV criteria for melancholia were applied to 1,970 Han Chinese women with recurrent MD recruited from 53 provincial mental health centers and psychiatric departments of general medical hospitals in 41 cities. Statistical analyses, utilizing Student's t-tests and Pearson's χ(2) , were calculated using SPSS 13.0.

RESULTS

Melancholic patients with MD were distinguished from nonmelancholic by being older, having a later age at onset, more episodes of illness and meeting more A criteria. They also had higher levels of neuroticism and rates of lifetime generalized anxiety disorder, panic disorder, and social and agoraphobia. They had significantly lower rates of childhood sexual abuse but did not differ on other stressful life events or rates of MD in their families.

DISCUSSION

Consistent with most prior findings in European and US populations, we find that melancholia is a more clinically severe syndrome than nonmelancholic depression with higher rates of comorbidity. The evidence that it is a more "biological" or qualitatively distinct syndrome, however, is mixed.

Do Different Depression Phenotypes Have Different Risks for Recurrent Coronary Heart Disease?

Although research has consistently established that depression and elevated depressive symptoms are associated with an increased risk of acute coronary syndrome (ACS) recurrence and mortality, clinical trials have failed to show that conventional depression interventions offset this risk. As depression is a complex and heterogeneous syndrome, we believe that using simpler, or intermediary, phenotypes rather than one complex phenotype may allow better identification of those at particular risk of ACS recurrence and mortality and may contribute to the development of specific depression treatments that would improve medical outcomes. Although there are many possible intermediary phenotypes, specifiers, and dimensions of depression, we will focus on only two when considering the relation between depression and risk of ACS recurrence and mortality: Inflammation-Induced Incident Depression and Anhedonic Depression. Future research on intermediary phenotypes of depression is needed to clarify which are associated with the greatest risk for ACS recurrence and mortality and which, if any, are benign. Theoretical advances in depression phenotyping may also help elucidate the behavioral and biological mechanisms underlying the increased risk of ACS among patients with specific depression phenotypes. Finally, tests of depression interventions may be guided by this new theoretical approach.

Sad benefit in face working memory: an emotional bias of melancholic depression

Emotion biases feature prominently in cognitive theories of depression and are a focus of psychological interventions. However, there is presently no stable neurocognitive marker of altered emotion-cognition interactions in depression. One reason may be the heterogeneity of major depressive disorder. Our aim in the present study was to find an emotional bias that differentiates patients with melancholic depression from controls, and patients with melancholic from those with non-melancholic depression. We used a working memory paradigm for emotional faces, where two faces with angry, happy, neutral, sad or fearful expression had to be retained over one second. Twenty patients with melancholic depression, 20 age-, education- and gender-matched control participants and 20 patients with non-melancholic depression participated in the study. We analysed performance on the working memory task using signal detection measures. We found an interaction between group and emotion on working memory performance that was driven by the higher performance for sad faces compared to other categories in the melancholic group. We computed a measure of "sad benefit", which distinguished melancholic and non-melancholic patients with good sensitivity and specificity. However, replication studies and formal discriminant analysis will be needed in order to assess whether emotion bias in working memory may become a useful diagnostic tool to distinguish these two syndromes.

Melancholia in Latin American studies: a distinct mood disorder for the ICD-11

OBJECTIVE

Melancholic depression is a lifetime diagnosis, typically with recurrent episodes. Melancholia, a syndrome with a long history and distinctive psychopathological features, is differentiated from major depression by the DSM-IV specifiers and partly described in the International Classification of Diseases - 10th edition. Within the present classification, it is frequently seen in severely ill patients with major depression and bipolar disorder. Nevertheless, it has a distinctive psychopathology and biological homogeneity in clinical experience and laboratory test markers, and it is differentially responsive to specific treatment interventions according to international studies. The objective of this study is to review the literature published by Latin American authors about Melancholia.

METHOD

We conducted a systematic search to identify scientific literature published by Latin American authors gathering information relevant to the revision of the classification of mental and behavioral disorders in patients with melancholic depression of the International Classification of Diseases - 10th edition. The review was specifically focused on literature from Brazil and Latin America in order to examine the specific Latin American contribution for the study of melancholia as a distinct entity.

RESULTS AND CONCLUSION

Melancholia can be identified as a separate mood disorder with unique psychopathology and psychoneuroendocrinology, worthy of separate attention in the classification systems. We therefore suggest that melancholia be positioned as a distinct, identifiable mood disorder that requires specific treatment.

The effect of pre- vs. post-reward attainment on EEG asymmetry in melancholic depression

Clinical investigators have long theorized about the role of reward processing and positive affect in depression. One theory posits that compared to nonmelancholic depressives, melancholic depressives experience less consummatory (i.e., post-reward), but comparably low anticipatory (prior to reward), positive affect. We tested whether frontal EEG asymmetry, a putative marker of the anticipatory reward system, is present only before an individual receives a reward or also after receiving a reward (i.e., during consummatory reward processing). We also examined whether melancholic depression, a condition characterized by a deficit in consummatory reward processing, is associated with abnormal EEG asymmetries in alpha band power. Effects in other frequency bands (delta, theta, or beta) were also explored. EEG was recorded in 34 controls, 48 nonmelancholic depressives, and 17 melancholic depressives during a slot machine task designed to elicit anticipatory and consummatory reward processing. Results indicated that, for alpha, the frontal EEG asymmetry of greater relative left activity was specific to anticipatory reward processing. During the consummatory phase, individuals with melancholic depression exhibited different posterior EEG asymmetries than individuals with nonmelancholic depression (and controls at a trend level). This second finding was largely due to melancholics exhibiting relatively lower right posterior activity and nonmelancholics exhibiting relatively lower left activity. These results suggest that a posterior asymmetry may be a marker for melancholic depression and aberrant consummatory reward processing.

Melancholic versus non-melancholic depression: differences on cognitive function. A longitudinal study protocol

BACKGROUND

Cognitive dysfunction is common among depressed patients. However, the pattern and magnitude of impairment during episodes of major depressive disorder (MDD) through to clinical remission remains unclear. Heterogeneity of depressive patients and the lack of longitudinal studies may account for contradictory results in previous research.

METHODS/DESIGN

This longitudinal study will analyze cognitive differences between CORE-defined melancholic depressed patients (n = 60) and non-melancholic depressed patients (n = 60). A comprehensive clinical and cognitive assessment will be performed at admission and after 6 months. Cognitive dysfunction in both groups will be longitudinally compared, and the persistence of cognitive impairment after clinical remission will be determined.

DISCUSSION

The study of neuropsychological dysfunction and the cognitive changes through the different phases of depression arise a wide variety of difficulties. Several confounding variables must be controlled to determine if the presence of depression could be considered the only factor accounting for group differences.

Impaired implicit learning and reduced pre-supplementary motor cortex size in early-onset major depression with melancholic features

BACKGROUND

Major depression is a heterogeneous disorder. Biological markers and cognitive tasks have been employed to distinguish clinical subtypes but results have been inconclusive.

METHODS

The current study assessed implicit learning with the Serial Reaction Time Task (SRTT) known to be sensitive to frontostriatal dysfunctions and regional brain volumes of the anterior supplementary motor area (pre-SMA) in participants with early-onset major depression (MD) of either melancholic (n=26) or non-melancholic (n=9) subtype, and 26 matched controls.

RESULTS

Depressive subjects with melancholic features but not those with non-melancholic depression showed implicit learning deficits. This deficit could not be explained in terms of more severe depression or psychomotor retardation. Regional volumes of the right pre-SMA were reduced in depressive subjects with melancholic features.

LIMITATIONS

Medication effects in depressive subjects and the small size of the non-melancholic sample should be taken into consideration when reviewing the implications of these results.

CONCLUSIONS

Deficits in implicit motor sequence learning seem to be an additional characteristic of the melancholic subtype of depression. It might be linked to dysfunction within structural or functionally altered frontostriatal circuits. Use of implicit sequence learning tasks could offer useful diagnostic and aetiological cues for future research.

Basic concepts of depression

This paper reviews concepts of depression, including history and classification. The original broad concept of melancholia included all forms of quiet insanity. The term depression began to appear in the nineteenth century as did the modern concept of affective disorders, with the core disturbance now viewed as one of mood. The 1930s saw the introduction of defined criteria into official diagnostic schemes. The modern separation into unipolar and bipolar disorder was introduced following empirical research by Angst and Perris in the 1960s. The partially overlapping distinctions between psychotic and neurotic depression, and between endogenous and reactive depression, started to generate debate in the 1920s, with considerable multivariate research in the 1960s. The symptom element in endogenous depression currently survives in melancholia or somatic syndrome. Life stress is common in various depressive pictures. Dysthymia, a valuable diagnosis, represents a form of what was regarded earlier as neurotic depression. Other subtypes are also discussed.

Improving the prediction of treatment response in depression: integration of clinical, cognitive, psychophysiological, neuroimaging, and genetic measures

Antidepressants are important in the treatment of depression, and selective serotonin reuptake inhibitors are first-line pharmacologic options. However, only 50% to 70% of patients respond to first treatment and <40% remit. Since depression is associated with substantial morbidity, mortality, and family burden, it is unfortunate and demanding on health resources that patients must remain on their prescribed medications for at least 4 weeks without knowing whether the particular antidepressant will be effective. Studies have suggested a number of predictors of treatment response, including clinical, psychophysiological, neuroimaging, and genetics, each with varying degrees of success and nearly all with poor prognostic sensitivity and specificity. Studies are yet to be conducted that use multiple measures from these different domains to determine whether sensitivity and specificity can be improved to predict individual treatment response. It is proposed that a focus on standardized testing methodologies across multiple testing modalities and their integration will be crucial for translation of research findings into clinical practice.