Meta-review of depressive subtyping models

Depression is more than the sum score of its parts: individual DSM symptoms have different risk factors

BACKGROUND

For diagnostic purposes, the nine symptoms that compose the DSM-5 criteria for major depressive disorder (MDD) are assumed to be interchangeable indicators of one underlying disorder, implying that they should all have similar risk factors. The present study investigates this hypothesis, using a population cohort that shifts from low to elevated depression levels.

METHOD

We assessed the nine DSM-5 MDD criterion symptoms (using the Patient Health Questionnaire; PHQ-9) and seven depression risk factors (personal and family MDD history, sex, childhood stress, neuroticism, work hours, and stressful life events) in a longitudinal study of medical interns prior to and throughout internship (n = 1289). We tested whether risk factors varied across symptoms, and whether a latent disease model could account for heterogeneity between symptoms.

RESULTS

All MDD symptoms increased significantly during residency training. Four risk factors predicted increases in unique subsets of PHQ-9 symptoms over time (depression history, childhood stress, sex, and stressful life events), whereas neuroticism and work hours predicted increases in all symptoms, albeit to varying magnitudes. MDD family history did not predict increases in any symptom. The strong heterogeneity of associations persisted after controlling for a latent depression factor.

CONCLUSIONS

The influence of risk factors varies substantially across DSM depression criterion symptoms. As symptoms are etiologically heterogeneous, considering individual symptoms in addition to depression diagnosis might offer important insights obfuscated by symptom sum scores.

The predictive power of subgroups: an empirical approach to identify depressive symptom patterns that predict response to treatment

BACKGROUND

Depression research has been trying to improve the response rates to treatments by identifying a valid set of differential predictor variables. Potential candidates have been proposed, one of which were different subtypes of depression. However, the results on the predictive quality of subtypes on treatment are conflicting.

METHODS

The analyzed data consisted of Hamilton Depression Rating Scales (HAM-D17) of 879 depressive inpatients, which were recruited in a naturalistic multicenter study. Mean length of stay was 9.9 weeks. In a first step, a Latent Class Analysis (LCA) was conducted to classify the patients into smaller groups. In a second step, the class variable was included in a Linear Mixed Effects model to predict the same patients' response to treatment.

RESULTS

Five classes were obtained from LCA, showing substantially different symptom profiles. One of the classes, with a symptom profile similar to melancholic depression, showed substantially slower response to treatment (i.e., estimated time to remission; 11.3 weeks) than the remaining classes in the study (6.6-8.6 weeks).

LIMITATIONS

The applied measurement instrument, the HAM-D17, did not include items for two additional, frequently found subtypes of depression: psychotic and atypical depression. Thus, these subtypes could not emerge in the LCA. Furthermore, there was no systematic variation of treatment in the data. Thus, a differential effect of the classes on treatment could not be measured.

CONCLUSIONS

The classification of patients according to their symptom profiles seems to be a potent predictor for treatment response. However, the obtained symptom patterns are not completely congruent with the theoretically proposed subgroups. Against the background of the results, dividing melancholic depression in a rather cognitive and vegetative subtype may be promising.

Establishing the bidirectional relationship between depression and subclinical arteriosclerosis--rationale, design, and characteristics of the BiDirect Study

BACKGROUND

Depression and cardiovascular diseases due to arteriosclerosis are both frequent and impairing conditions. Depression and (subclinical) arteriosclerosis appear to be related in a bidirectional way, and it is plausible to assume a partly joint causal relationship. However, the biological mechanisms and the behavioral pathways that lead from depression to arteriosclerosis and vice versa remain to be exactly determined.

METHODS/DESIGN

This study protocol describes the rationale and design of the prospective BiDirect Study that aims at investigating the mutual relationship between depression and (subclinical) arteriosclerosis. BiDirect is scheduled to follow-up three distinct cohorts of individuals ((i) patients with acute depression (N = 999), (ii) patients after an acute cardiac event (N = 347), and (iii) reference subjects from the general population (N = 912)). Over the course of 12 years, four personal examinations are planned to be conducted. The core examination program, which will remain identical across follow-ups, comprises a personal interview (e.g. medical diagnoses, health care utilization, lifestyle and risk behavior), a battery of self-administered questionnaires (e.g. depressive symptoms, readiness to change health behavior, perceived health-related quality of life), sensory (e.g. olfaction, pain) and neuropsychological (e.g. memory, executive functions, emotional processing, manual dexterity) assessments, anthropometry, body impedance measurement, a clinical work-up regarding the vascular status (e.g. electrocardiogram, blood pressure, intima media thickness), the taking of blood samples (serum and plasma, DNA), and structural and functional resonance imaging of the brain (e.g. diffusion tensor imaging, resting-state, emotional faces processing). The present report includes BiDirect-Baseline, the first data collection wave.

DISCUSSION

Due to its prospective character, the integration of three distinct cohorts, the long follow-up time window, the diligent diagnosis of depression taking depression subtypes into account, the consideration of relevant comorbidities and risk factors, the assessment of indicators of (subclinical) arteriosclerosis in different vascular territories, and the structural and functional brain imaging that is performed for a large number of participants, the BiDirect Study represents an innovative approach that combines population-based cohorts with sophisticated clinical work-up methods and that holds the potential to overcome many of the drawbacks characterizing earlier investigations.

Norepinephrine transporter occupancy by nortriptyline in patients with depression: a positron emission tomography study with (S,S)-[¹⁸F]FMeNER-D₂

Norepinephrine transporter (NET) plays important roles in the treatment of various neuropsychiatric disorders, such as depression and attention deficit hyperactivity disorder (ADHD). Nortriptyline is a NET-selective tricyclic antidepressant (TCAs) that has been widely used for the treatment of depression. Previous positron emission tomography (PET) studies have reported over 80% serotonin transporter occupancy with clinical doses of selective serotonin reuptake inhibitors (SSRIs), but there has been no report of NET occupancy in patients treated with relatively NET-selective antidepressants. In the present study, we used PET and (S,S)-[18¹⁸F]FMeNER-D₂ to investigate NET occupancies in the thalamus in 10 patients with major depressive disorder taking various doses of nortriptyline, who were considered to be responders to the treatment. Reference data for the calculation of occupancy were derived from age-matched healthy controls. The result showed approximately 50-70% NET occupancies in the brain as a result of the administration of 75-200 mg/d of nortriptyline. The estimated effective dose (ED₅₀) and concentration (EC₅₀) required to induce 50% occupancy was 65.9 mg/d and 79.8 ng/ml, respectively. Furthermore, as the minimum therapeutic level of plasma nortriptyline for the treatment of depression has been reported to be 70 ng/ml, our data indicate that this plasma nortriptyline concentration corresponds to approximately 50% NET occupancy measured with PET, suggesting that more than 50% of central NET occupancy would be appropriate for the nortriptyline treatment of patients with depression.

Symptom-based subtypes of depression and their psychosocial correlates: a person-centered approach focusing on the influence of sex

BACKGROUND

Reducing the complexity of major depressive disorder by symptom-based subtypes constitutes the basis of more specific treatments. To date, few studies have empirically derived symptom subtypes separated by sex, although the impact of sex has been widely accepted in depression research.

METHODS

The community-based sample included 373 males and 443 females from the Zurich Program for Sustainable Development of Mental Health Services (ZInEP) manifesting depressive symptoms in the past 12 months. Latent Class Analysis (LCA) was performed separately by sex to extract sex-related depression subtypes. The subtypes were characterized by psychosocial characteristics.

RESULTS

Three similar subtypes were found in both sexes: a severe typical subtype (males: 22.8%; females: 35.7%), a severe atypical subtype (males: 17.4%; females: 22.6%), and a moderate subtype (males: 25.2%; females: 41.8%). In males, two additional subgroups were identified: a severe irritable/angry-rejection sensitive (IARS) subtype (30%) comprising the largest group, and a small psychomotor retarded subtype (4%). Males belonging to the severe typical subtype exhibited the lowest masculine gender role orientation, while females of the typical subtype showed more anxiety disorders. The severe atypical subtype was associated with eating disorders in both sexes and with alcohol/drug abuse/dependence in females. In contrast, alcohol/drug abuse/dependence was associated with the severe IARS subtype in males.

LIMITATIONS

The study had a cross-sectional design, allowing for no causal inferences.

CONCLUSIONS

This study contributes to a better understanding of sex-related depression subtypes, which can be well distinguished on the basis of symptom profiles. This provides the base for future research investigating the etiopathogenesis and effective treatment of the heterogeneous depression disorder.

The impact of individual depressive symptoms on impairment of psychosocial functioning

Previous studies have established that scores on Major Depressive Disorder scales are correlated with measures of impairment of psychosocial functioning. It remains unclear, however, whether individual depressive symptoms vary in their effect on impairment, and if so, what the magnitude of these differences might be. We analyzed data from 3,703 depressed outpatients in the first treatment stage of the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study. Participants reported on the severity of 14 depressive symptoms, and stated to what degree their depression impaired psychosocial functioning (in general, and in the five domains work, home management, social activities, private activities, and close relationships). We tested whether symptoms differed in their associations with impairment, estimated unique shared variances of each symptom with impairment to assess the degree of difference, and examined whether symptoms had variable impacts across impairment domains. Our results show that symptoms varied substantially in their associations with impairment, and contributed to the total explained variance in a range from 0.7% (hypersomnia) to 20.9% (sad mood). Furthermore, symptoms had significantly different impacts on the five impairment domains. Overall, sad mood and concentration problems had the highest unique associations with impairment and were among the most debilitating symptoms in all five domains. Our findings are in line with a growing chorus of voices suggesting that symptom sum-scores obfuscate relevant differences between depressed patients and that substantial rewards will come from close attention to individual depression symptoms.

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.

Racial and ethnic differences in depressive subtypes and access to mental health care in the United States

OBJECTIVES

Racial and ethnic minorities in the U.S. underutilize mental health service for mood disorders. This study sought to identify depressive subtypes associated with low use of mental health services across racial and ethnic groups based on a large, nationally representative sample of adults in the U.S.

METHODS

Based on latent class analysis, we identified the latent profile of depressive symptoms among those who endorsed lifetime depressed mood or anhedonia in the 2001-2002 National Epidemiological Survey on Alcohol and Related Condition (302 Asian Americans; 8602 Whites; 2266 Blacks; 2254 Hispanics). Proportions and types of lifetime mental health service use across depressive symptom subtypes were assessed and compared across the racial and ethnic categories.

RESULTS

A four class model of depressive subtypes was examined across race and ethnicity ("mild," "cognitive," "psychosomatic," and "severe"). Asian Americans, blacks, and Hispanics with "severe" subtype of depression had significantly lower odds of mental health service use compared to whites with "severe" subtype of depression. While Asian Americans did not have higher proportion of "psychosomatic" subtype than other race and ethnic groups, Asian Americans with "cognitive" subtype of depression significantly underused mental health services compared to Asian Americans with "psychosomatic" subtype of depression (Odds ratio:0.34, 95% Confidence interval:0.13,0.91).

LIMITATION

We were unable to account for heterogeneity of the subethnic group compositions based on country of origin and other socio-demographic factors.

CONCLUSIONS

A targeted outreach intervention to raise awareness among Asian Americans, blacks, and Hispanics with "severe" subtype and Asian Americans with "cognitive" subtype of depression may reduce disparity in mental health service utilization across racial and ethnic groups.

Mood disturbance after infection

OBJECTIVE

An aetiological link between acute infection and major depression has long been hypothesized, and is increasingly gaining recognition within contemporary literature. This review aims to examine the evidence for such a link, specifically between acute, self-limiting infection and major depression, and to summarize the current understanding of pathophysiological mechanisms underlying this link.

METHODS

Relevant articles were sourced via an online search of published literature from Embase, MEDLINE, PsycINFO and PubMed using a variety of search terms including mood disorder, depression, infection and inflammation. Additionally, a search for articles from the bibliographies of retrieved papers was conducted.

RESULTS

Findings from retrospective studies suggest an association between infection and subsequent mood disturbance, including major depression. This association has been confirmed by studies employing prospective observational or experimental challenge designs. The available evidence supports a multifactorial basis of vulnerability towards major depression in the context of acute infection. Genetic, neuroendocrine, autonomic and psychosocial factors may interact to potentiate the likelihood of a severe and prolonged depressive response to an immunological stressor in some individuals.

CONCLUSION

Mood disturbance is likely to have a host-protective role in the context of an acute sickness response to infection. However, this usually adaptive and reversible response may progress in some vulnerable individuals into a more sustained and severe pattern of behavioural and physiological changes of major depression. Further research is needed to delineate the factors that predispose, precipitate and perpetuate depression in the context of acute infective illness. Such insights will inform effective prevention and treatment strategies.

Are variations in whole blood BDNF level associated with the BDNF Val66Met polymorphism in patients with first episode depression?

Brain derived neurotrophic factor (BDNF) seems to play an important role in the pathophysiology of affective disorders. The current study investigated whether blood level BDNF is correlated with the severity of depressive symptoms and recent (six months prior to onset of depression) experience of stressful life events (SLE) in a cohort of patients with a first depressive episode. 262 patients with first episode depression (females 174, males 88, age range 18-70, mean age 41) participated and control sample of 84 participants was included (females 52, males 32, age range 22-70, mean age 42). Symptomatology was rated using Hamilton Rating Scale for Depression (HAMD-17) and Becks Depression Inventory (BDI 21). No differences in whole blood BDNF was seen in relation to the BDNF Val66Met polymorphism and no significant correlations between whole blood BDNF and HAMD-17 or BDI 21 scores were found. No significant associations between the experiences of SLE before onset of depression and BDNF level were observed. Finally, peripheral BDNF differentiated between patients and healthy control persons. In the current sample of first episode depressed patients, the Val66Met polymorphism was not associated with whole blood BDNF and whole blood BNDF level was not associated with the experience of recent SLE.

Meta-analytic evidence for neuroimaging models of depression: state or trait?

BACKGROUND

Major Depressive Disorder (MDD) is a leading cause of disease burden worldwide. With the rapid growth of neuroimaging research on relatively small samples, meta-analytic techniques are becoming increasingly important. Here, we aim to clarify the support in fMRI literature for three leading neurobiological models of MDD: limbic-cortical, cortico-striatal and the default mode network.

METHODS

Searches of PubMed and Web of Knowledge, and manual searches, were undertaken in early 2011. Data from 34 case-control comparisons (n=1165) and 6 treatment studies (n=105) were analysed separately with two meta-analytic methods for imaging data: Activation Likelihood Estimation and Gaussian-Process Regression.

RESULTS

There was broad support for limbic-cortical and cortico-striatal models in the case-control data. Evidence for the role of the default mode network was weaker. Treatment-sensitive regions were primarily in lateral frontal areas.

LIMITATIONS

In any meta-analysis, the increase in the statistical power of the inference comes with the risk of aggregating heterogeneous study pools. While we believe that this wide range of paradigms allows identification of key regions of dysfunction in MDD (regardless of task), we attempted to minimise such risks by employing GPR, which models such heterogeneity.

CONCLUSIONS

The focus of treatment effects in frontal areas indicates that dysregulation here may represent a biomarker of treatment response. Since the dysregulation in many subcortical regions in the case-control comparisons appeared insensitive to treatment, we propose that these act as trait vulnerability markers, or perhaps treatment insensitivity. Our findings allow these models of MDD to be applied to fMRI literature with some confidence.

Validation of a new prototypic measure of melancholia

Multiple approaches have been adopted in an attempt to effectively identify and discriminate melancholic and non-melancholic depressive subtypes. We recently developed the Sydney Melancholia Prototype Index (SMPI) which incorporates antecedent and illness course variables as well as symptoms, with clinician-rated and self-rated SMPI versions, and with the former having been shown to have superior sensitivity and specificity in discriminating melancholic from non-melancholic depression. The aim of this study was to further evaluate the capacity of the SMPI to identify melancholia in comparison to DSM-based and clinician-judged assignments. The sample comprised 214 patients diagnosed with melancholic or non-melancholic depression according to a detailed clinical assessment and by the Mini International Neuropsychiatric Structured Interview (MINI) assessing formal DSM-IV melancholia criteria. DSM-IV assignment to melancholic versus non-melancholic depression was contrasted with clinician-judged allocation, the combination of these two strategies ("concordant diagnoses"), and to the SMPI (CR or clinician-rated and SR or self-report versions), with the likely validity of each approach examined against historical ascriptions for melancholia. DSM-IV criteria assigned the highest percentage of the sample with a melancholic diagnosis (64%), whereas the SMPI-SR assigned the smallest percentage with a melancholic diagnosis (37%). DSM-IV assignment was associated with the fewest number of validating variables, whilst SMPI-CR and independent clinician diagnosis were associated with the greatest number of differentiating variables including negative childhood experiences, past and recent stressors, satisfaction with life and perceived social support. These comparative analyses provide further support for the SMPI-CR in identifying and discriminating melancholic depression from non-melancholic depression. Replication of these findings in other samples with independent raters is recommended.

Antepartum depression severity is increased during seasonally longer nights: relationship to melatonin and cortisol timing and quantity

Current research suggests that mood varies from season to season in some individuals, in conjunction with light-modulated alterations in chronobiologic indices such as melatonin and cortisol. The primary aim of this study was to evaluate the effects of seasonal variations in darkness on mood in depressed antepartum women, and to determine the relationship of seasonal mood variations to contemporaneous blood melatonin and cortisol measures; a secondary aim was to evaluate the influence of seasonal factors on measures of melancholic versus atypical depressive symptoms. We obtained measures of mood and overnight concentrations of plasma melatonin and serum cortisol in 19 depressed patients (DP) and 12 healthy control (HC) antepartum women, during on-going seasonal variations in daylight/darkness, in a cross-sectional design. Analyses of variance showed that in DP, but not HC, Hamilton Depression Rating Scale (HRSD) scores were significantly higher in women tested during seasonally longer versus shorter nights. This exacerbation of depressive symptoms occurred when the dim light melatonin onset, the melatonin synthesis offset, and the time of maximum cortisol secretion (acrophase) were phase-advanced (temporally shifted earlier), and melatonin quantity was reduced, in DP but not HC. Serum cortisol increased across gestational weeks in both the HC and DP groups, which did not differ significantly in cortisol concentration. Nevertheless, serum cortisol concentration correlated positively with HRSD score in DP but not HC; notably, HC showed neither significant mood changes nor altered melatonin and cortisol timing or quantity in association with seasonal variations. These findings suggest that depression severity during pregnancy may become elevated in association with seasonally related phase advances in melatonin and cortisol timing and reduced melatonin quantity that occur in DP, but not HC. Thus, women who experience antepartum depression may be more susceptible than their nondepressed counterparts to phase alterations in melatonin and cortisol timing during seasonally longer nights. Interventions that phase delay melatonin and/or cortisol timing-for example, increased exposure to bright evening light-might serve as an effective intervention for antepartum depressions whose severity is increased during seasonally longer nights.

Age-dependent symptomatology of depression in hospitalized patients and its implications for DSM-5

BACKGROUND

We investigated effects of current age and age at onset on symptomatology of depression with reference to proposed revisions in DSM-5.

METHODS

The study entailed medical records of 326 inpatients diagnosed with major depressive disorder, including 520 depressive episodes, with 113 first episodes lifetime. Subjects were divided into three groups: young-adults, middle-aged adults and older adults.

RESULTS

In young-adults, active suicidal ideation, lifetime suicidal attempts, irritability, anhedonia and persistent depressive symptoms between the episodes were more frequent than in the other groups. Among older adults, depression was associated with insomnia, hypochondriasis, somatization, decreased appetite, weight loss, memory impairment and decreased activity. The older age was not associated with higher number of previous episodes of depression, bigger severity or duration of a single episode or a different degree of remission. Early-onset depression was associated with more suicidal attempts.

LIMITATIONS

The study was retrospective and the sample may be treated only as representative for hospitalized depressed patients.

CONCLUSIONS

Age and age at onset are important factors influencing the course and symptomatology of a depressive episode. Depressive episodes with anxiety and with suicide risk severity are important specifiers that vary with the age at onset and/or age of the patient and should be considered for inclusion in the DSM-5 revision.

Irritable mood as a symptom of depression in youth: prevalence, developmental, and clinical correlates in the Great Smoky Mountains Study

OBJECTIVE

DSM-IV grants episodic irritability an equal status to low mood as a cardinal criterion for the diagnosis of depression in youth, yet not in adults; however, evidence for irritability as a major criterion of depression in youth is lacking. This article examines the prevalence, developmental characteristics, associations with psychopathology, and longitudinal stability of irritable mood in childhood and adolescent depression.

METHOD

Data from the prospective population-based Great Smoky Mountains Study (N = 1,420) were used. We divided observations on 9- to 16-year-olds who met criteria for a diagnosis of depression into 3 groups: those with depressed mood and no irritability, those with irritability and no depressed mood, and those with both depressed and irritable mood. We compared these groups using robust regression models on adolescent characteristics and early adult (ages 19-21 years) depression outcomes.

RESULTS

Depressed mood was the most common cardinal mood in youth meeting criteria for depression (58.7%), followed by the co-occurrence of depressed and irritable mood (35.6%); irritable mood alone was rare (5.7%). Youth with depressed and irritable mood were similar in age and developmental stage to those with depression, but had significantly higher rates of disruptive disorders. The co-occurrence of depressed and irritable mood was associated with higher risk for comorbid conduct disorder in girls (gender-by-group interaction, F1,132 = 4.66, p = .03).

CONCLUSIONS

Our study findings do not support the use of irritability as a cardinal mood criterion for depression. However, the occurrence of irritability in youth depression is associated with increased risk of disruptive behaviors, especially in girls.

The subjective experience and phenomenology of depression following first episode psychosis: a qualitative study using photo-elicitation

BACKGROUND

Depression following first episode psychosis (FEP) is a frequent occurrence, with profound impact on recovery and outcome. Whilst many theories exist about the causes of depression here, research to date has been based on nosology imported wholesale from affective disorder, with little primary research on the subjective experience. This study aimed to explore the subjective experience and phenomenological features of post-psychotic depression in FEP.

METHOD

A qualitative methodology, photo-elicitation, together with unstructured interviews, was used to characterise aspects of depression following FEP and analysed using contemporary framework analysis.

RESULTS

Depression was reported by participants as linked to the experience of and recovery from psychosis. The psychotic episode was a traumatic event followed by subjective doubt, shame and embarrassment. Loss and social isolation were central. Core biological symptoms did not feature.

LIMITATIONS

Despite the relatively small sample size, this study was able to generate in-depth data that provides useful and novel insight. Whilst generalisability is incompatible with qualitative methodology, further research using the same methodology would generate a wider range of experiences and perspectives.

CONCLUSIONS

Understanding this dimension of psychosis in and of itself has the potential to improve and aid development of more effective and appropriately targeted interventions and associated outcomes.

Evidence for a differential role of HPA-axis function, inflammation and metabolic syndrome in melancholic versus atypical depression

The hypothalamic-pituitary-adrenal (HPA) axis and the inflammatory response system have been suggested as pathophysiological mechanisms implicated in the etiology of major depressive disorder (MDD). Although meta-analyses do confirm associations between depression and these biological systems, effect sizes vary greatly among individual studies. A potentially important factor explaining variability is heterogeneity of MDD. Aim of this study was to evaluate the association between depressive subtypes (based on latent class analysis) and biological measures. Data from 776 persons from the Netherlands Study of Depression and Anxiety, including 111 chronic depressed persons with melancholic depression, 122 with atypical depression and 543 controls were analyzed. Inflammatory markers (C-reactive protein, interleukin-6, tumor necrosis factor-α), metabolic syndrome components, body mass index (BMI), saliva cortisol awakening curves (area under the curve with respect to the ground (AUCg) and with respect to the increase (AUCi)), and diurnal cortisol slope were compared among groups. Persons with melancholic depression had a higher AUCg and higher diurnal slope compared with persons with atypical depression and with controls. Persons with atypical depression had significantly higher levels of inflammatory markers, BMI, waist circumference and triglycerides, and lower high-density lipid cholesterol than persons with melancholic depression and controls. This study confirms that chronic forms of the two major subtypes of depression are associated with different biological correlates with inflammatory and metabolic dysregulation in atypical depression and HPA-axis hyperactivity in melancholic depression. The data provide further evidence that chronic forms of depressive subtypes differ not only in their symptom presentation, but also in their biological correlates. These findings have important implications for future research on pathophysiological pathways of depression and treatment.

Role of orexin in the pathophysiology of depression: potential for pharmacological intervention

Depression is a devastating mental disorder with an increasing impact throughout the world, whereas the efficacy of currently available pharmacological treatment is still limited. Growing evidence from preclinical and clinical studies suggests that orexins (neuropeptides that are also known as hypocretins) and their receptors are involved in the physiopathology of depression. Indeed, the orexinergic system regulates functions that are disturbed in depressive states such as sleep, reward system, feeding behavior, the stress response and monoaminergic neurotransmission. Nevertheless, the precise role of orexins in behavioral and neurophysiological impairments observed in depression is still unclear. Both hypoactivity and hyperactivity of orexin signaling pathways have been found to be associated with depression. These discrepancies in the literature prompted the necessity for additional investigations, as the orexinergic system appears to be a promising target to treat the symptoms of depression. This assumption is underlined by recent data suggesting that pharmacological blockade of orexin receptors induces a robust antidepressant-like effect in an animal model of depression. Further preclinical and clinical studies are needed to progress the overall understanding of the orexinergic alterations in depression, which will eventually translate preliminary observations into real therapeutic potential. The aim of this paper is to provide an overview of human and animal research dedicated to the study of the specific involvement of orexins in depression, and to propose a framework in which disturbances of the orexinergic system are regarded as an integral component of the etiology of depression.

Does early-onset chronic or recurrent major depression impact outcomes with antidepressant medications? A CO-MED trial report

BACKGROUND

Prior studies have suggested that major depressive disorder (MDD) with pre-adult onset represents a distinct subtype with greater symptom severity and higher rates of suicidal ideation. Whether these patients have poorer response to various types of antidepressant treatment than those with adult-onset MDD is unclear. Method A total of 665 psychiatric and primary care out-patients (aged 18-75 years) with non-psychotic chronic or recurrent MDD participated in a single-blind, randomized trial that compared the efficacy of escitalopram plus placebo, bupropion sustained-release plus escitalopram, or venlafaxine extended-release plus mirtazapine. We compared participants who self-reported MDD onset (before age 18) to those with a later onset (adult onset) with respect to baseline characteristics and treatment/outcome variables at 12 and 28 weeks.

RESULTS

Early-onset chronic/recurrent MDD was associated with a distinct set of sociodemographic (female, younger age) and clinical correlates (longer duration of illness, greater number of prior episodes, greater likelihood of atypical features, higher rates of suicidality and psychiatric co-morbidity, fewer medical problems, poorer quality of life, greater history of child abuse/neglect). However, results from unadjusted and adjusted analyses showed no significant differences in response, remission, tolerability of medications, quality of life, or retention at 12 or 28 weeks.

CONCLUSIONS

Although early-onset chronic/recurrent MDD is associated with a more severe clinical picture, it does not seem to be useful for predicting differential treatment response to antidepressant medication. Clinicians should remain alert to an increased risk of suicidality in this population.

Psychological and pharmacological interventions for depression in patients with diabetes mellitus and depression

BACKGROUND

Depression occurs frequently in patients with diabetes mellitus and is associated with a poor prognosis.

OBJECTIVES

To determine the effects of psychological and pharmacological interventions for depression in patients with diabetes and depression.

SEARCH METHODS

Electronic databases were searched for records to December 2011. We searched CENTRAL in The Cochrane Library, MEDLINE, EMBASE, PsycINFO, ISRCTN Register and clinicaltrials.gov. We examined reference lists of included RCTs and contacted authors.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) investigating psychological and pharmacological interventions for depression in adults with diabetes and depression. Primary outcomes were depression and glycaemic control. Secondary outcomes were adherence to diabetic treatment regimens, diabetes complications, death from any cause, healthcare costs and health-related quality of life (HRQoL).

DATA COLLECTION AND ANALYSIS

Two review authors independently examined the identified publications for inclusion and extracted data from included studies. Random-effects model meta-analyses were performed to compute overall estimates of treatment outcomes.

MAIN RESULTS

The database search identified 3963 references. Nineteen trials with 1592 participants were included. Psychological intervention studies (eight trials, 1122 participants, duration of therapy three weeks to 12 months, follow-up after treatment zero to six months) showed beneficial effects on short (i.e. end of treatment), medium (i.e. one to six months after treatment) and long-term (i.e. more than six months after treatment) depression severity (range of standardised mean differences (SMD) -1.47 to -0.14; eight trials). However, between-study heterogeneity was substantial and meta-analyses were not conducted. Short-term depression remission rates (OR 2.88; 95% confidence intervals (CI) 1.58 to 5.25; P = 0.0006; 647 participants; four trials) and medium-term depression remission rates (OR 2.49; 95% CI 1.44 to 4.32; P = 0.001; 296 participants; two trials) were increased in psychological interventions compared to usual care. Evidence regarding glycaemic control in psychological intervention trials was heterogeneous and inconclusive. QoL did not improve significantly based on the results of three psychological intervention trials compared to usual care. Healthcare costs and adherence to diabetes and depression medication were examined in only one study and reliable conclusions cannot be drawn. Diabetes complications and death from any cause have not been investigated in the included psychological intervention trials.With regards to the comparison of pharmacological interventions versus placebo (eight trials; 377 participants; duration of intervention three weeks to six months, no follow-up after treatment) there was a moderate beneficial effect of antidepressant medication on short-term depression severity (all studies: SMD -0.61; 95% CI -0.94 to -0.27; P = 0.0004; 306 participants; seven trials; selective serotonin reuptake inhibitors (SSRI): SMD -0.39; 95% CI -0.64 to -0.13; P = 0.003; 241 participants; five trials). Short-term depression remission was increased in antidepressant trials (OR 2.50; 95% CI 1.21 to 5.15; P = 0.01; 136 participants; three trials). Glycaemic control improved in the short term (mean difference (MD) for glycosylated haemoglobin A1c (HbA1c) -0.4%; 95% CI -0.6 to -0.1; P = 0.002; 238 participants; five trials). HRQoL and adherence were investigated in only one trial each showing no statistically significant differences. Medium- and long-term depression and glycaemic control outcomes as well as healthcare costs, diabetes complications and mortality have not been examined in pharmacological intervention trials. The comparison of pharmacological interventions versus other pharmacological interventions (three trials, 93 participants, duration of intervention 12 weeks, no follow-up after treatment) did not result in significant differences between the examined pharmacological agents, except for a significantly ameliorated glycaemic control in fluoxetine-treated patients (MD for HbA1c -1.0%; 95% CI -1.9 to -0.2; 40 participants) compared to citalopram in one trial.

AUTHORS' CONCLUSIONS

Psychological and pharmacological interventions have a moderate and clinically significant effect on depression outcomes in diabetes patients. Glycaemic control improved moderately in pharmacological trials, while the evidence is inconclusive for psychological interventions. Adherence to diabetic treatment regimens, diabetes complications, death from any cause, health economics and QoL have not been investigated sufficiently. Overall, the evidence is sparse and inconclusive due to several low-quality trials with substantial risk of bias and the heterogeneity of examined populations and interventions.

Clinical patterns and treatment outcome in patients with melancholic, atypical and non-melancholic depressions

OBJECTIVE

To assess sociodemographic, clinical and treatment factors as well as depression outcome in a large representative clinical sample of psychiatric depressive outpatients and to determine if melancholic and atypical depression can be differentiated from residual non-melancholic depressive conditions.

SUBJECTS/MATERIALS AND METHOD

A prospective, naturalistic, multicentre, nationwide epidemiological study of 1455 depressive outpatients was undertaken. Severity of depressive symptoms was assessed by the Hamilton Depression Rating Scale (HDRS) and the Self Rated Inventory of Depressive Symptomatology (IDS-SR(30)). IDS-SR(30) defines melancholic and atypical depression according to DSM-IV criteria. Assessments were carried out after 6-8 weeks of antidepressant treatment and after 14-20 weeks of continuation treatment.

RESULTS

Melancholic patients (16.2%) were more severely depressed, had more depressive episodes and shorter episode duration than atypical (24.7%) and non-melancholic patients. Atypical depressive patients showed higher rates of co-morbid anxiety disorders and substance abuse. Melancholic patients showed lower rates of remission.

CONCLUSION

Our study supports a different clinical pattern and treatment outcome for melancholic and atypical depression subtypes.

Structure of major depressive disorder in adolescents and adults in the US general population

BACKGROUND

Although techniques such as latent class analysis have been used to derive empirically based subtypes of depression in adult samples, there is limited information on subtypes of depression in youth.

AIMS

To identify empirically based subtypes of depression in a nationally representative sample of US adolescents, and to test the comparability of subtypes of depression in adolescents with those derived from a nationally representative sample of adults.

METHOD

Respondents included 912 adolescents and 805 adults with a 12-month major depressive disorder, selected from the National Comorbidity Survey Adolescent Supplement and the National Comorbidity Survey Replication samples respectively. Latent class analysis was used to identify subtypes of depression across samples. Sociodemographic and clinical correlates of derived subtypes were also examined to establish their validity.

RESULTS

Three subtypes of depression were identified among adolescents, whereas four subtypes were identified among adults. Two of these subtypes displayed similar diagnostic profiles across adolescent and adult samples (P = 0.43); these subtypes were labelled 'severe typical' (adults 45%, adolescents 35%) and 'atypical' (adults 16%, adolescents 26%). The latter subtype was characterised by increased appetite and weight gain.

CONCLUSIONS

The structure of depression observed in adolescents is highly similar to the structure observed in adults. Longitudinal research is necessary to evaluate the stability of these subtypes of depression across development.

Efficacy of light therapy for perinatal depression: a review

Perinatal depression is an important public health problem affecting 10% to 20% of childbearing women. Perinatal depression is associated with significant morbidity, and has enormous consequences for the wellbeing of the mother and child. During the perinatal period, treatment of depression, which could affect the mother and child during pregnancy and lactation, poses a complex problem for both mother and clinician. Bright light therapy may be an attractive treatment for perinatal depression because it is low cost, home-based, and has a much lower side effect profile than pharmacotherapy. The antidepressant effects of bright light are well established, and there are several rationales for expecting that bright light might also be efficacious for perinatal depression. This review describes these rationales, summarizes the available evidence on the efficacy of bright light therapy for perinatal depression, and discusses future directions for investigation of bright light therapy as a treatment for perinatal depression.

Seasonality in depressive and anxiety symptoms among primary care patients and in patients with depressive and anxiety disorders; results from the Netherlands Study of Depression and Anxiety

BACKGROUND

Little is known about seasonality of specific depressive symptoms and anxiety symptoms in different patient populations. This study aims to assess seasonal variation of depressive and anxiety symptoms in a primary care population and across participants who were classified in diagnostic groups 1) healthy controls 2) patients with a major depressive disorder, 3) patients with any anxiety disorder and 4) patients with a major depression and any anxiety disorder.

METHODS

Data were used from the Netherlands Study of Depression and Anxiety (NESDA). First, in 5549 patients from the NESDA primary care recruitment population the Kessler-10 screening questionnaire was used and data were analyzed across season in a multilevel linear model. Second, in 1090 subjects classified into four groups according to psychiatric status according to the Composite International Diagnostic Interview, overall depressive symptoms and atypical versus melancholic features were assessed with the Inventory of Depressive Symptoms. Anxiety and fear were assessed with the Beck Anxiety Inventory and the Fear questionnaire. Symptom levels across season were analyzed in a linear regression model.

RESULTS

In the primary care population the severity of depressive and anxiety symptoms did not show a seasonal pattern. In the diagnostic groups healthy controls and patients with any anxiety disorder, but not patients with a major depressive disorder, showed a small rise in depressive symptoms in winter. Atypical and melancholic symptoms were both elevated in winter. No seasonal pattern for anxiety symptoms was found. There was a small gender related seasonal effect for fear symptoms.

CONCLUSIONS

Seasonal differences in severity or type of depressive and anxiety symptoms, as measured with a general screening instrument and symptom questionnaires, were absent or small in effect size in a primary care population and in patient populations with a major depressive disorder and anxiety disorders.