Diagnostic criteria are not always useful to discriminate major depression with anxious distress (ADS-D; Diagnostic and Statistical Manual for Mental Disorders, version-5 [DSM-5] criteria) from mixed depression (Koukopoulos’ criteria; KMX-D). So, clinicians need alternative tools to improve their diagnostic ability and to choose the most appropriate treatment. The aim of the present study is to identify socio-demographic and clinical features that discriminate patients with ADS-D from those with KMX-D.

Two hundred and forty-one consecutive outpatients with unipolar (51%) and bipolar (49%) disorder, fulfilling DSM-5 criteria for a current major depressive episode (MDE) and with a 21-item Hamilton Depression Rating Scale score ≥ 14, were recruited and treated in a prospective observational study.

Ten percent of patients met criteria for KMX-D, 22% ADS-D, and 37% for both. Irritable premorbid temperament, mixed depression polarity at onset, mixed depression recurrence, and a high number of mania symptoms at intake were typical features of patients with KMX-D. Depressive polarity at onset, a low number of mania symptoms at intake, and generalized anxiety disorder comorbidity were typical features of patients with ADS-D. Multinomial logistic regression confirmed that higher rate of irritable temperament and higher Young Mania Rating Scale total score differentiated patients with KMX-D from patients with pure MDE.

Our findings suggest some clinical features that could help differentiate between ADS-D and KMX-D in patients meeting both conditions and to select the appropriate treatment. However, the small sample size may have limited the power to detect differences between the groups. Further research is needed to confirm the results of present study.

Most people with major depressive episodes meet the criteria for the anxious distress (AD) specifier defined by DSM-5 as the presence of symptoms such as feelings of tension, restlessness, difficulty concentrating, and fear that something awful may happen. This cross-sectional study was aimed at identifying clinical correlates of AD in people with unipolar or bipolar depression.

Inpatients with a current major depressive episode were included. Data on socio-demographic and clinical variables were collected. The SCID-5 was used to diagnose depressive episodes and relevant specifiers. The Montgomery–Åsberg Depression Rating Scale (MADRS) and Young Mania Rating Scale (YMRS) were used to assess the severity of depressive and manic (mixed) symptoms, respectively. Multiple logistic regression analyses were carried out to identify clinical correlates of AD.

We included 206 people (mean age: 48.4 ± 18.6 yrs.; males: 38.8%) admitted for a major depressive episode (155 with major depressive disorder and 51 with bipolar disorder). Around two-thirds of the sample (N = 137; 66.5%) had AD. Multiple logistic regression models showed that AD was associated with mixed features, higher YMRS scores, psychotic features, and a diagnosis of major depressive disorder (p < 0.05).

Despite some limitations, including the cross-sectional design and the inpatient setting, our study shows that AD is likely to be associated with mixed and psychotic features, as well as with unipolar depression. The identification of these clinical domains may help clinicians to better contextualize AD in the context of major depressive episodes.

Major depression is associated with changes in plasma L-carnitine and acetyl-L-carnitine. But its association with acylcarnitines remains unclear. The aim of this study was to assess metabolomic profiles of 38 acylcarnitines in patients with major depression before and after treatment compared to healthy controls (HCs).

Metabolomic profiles of 38 plasma short-, medium-, and long-chain acylcarnitines were performed by liquid chromatography-mass spectrometry in 893 HCs from the VARIETE cohort and 460 depressed patients from the METADAP cohort before and after 6 months of antidepressant treatment.

As compared to HCs, depressed patients had lower levels of medium- and long-chain acylcarnitines. After 6 months of treatment, increased levels of medium- and long-chain acyl-carnitines were observed that no longer differed from those of controls. Accordingly, several medium- and long-chain acylcarnitines were negatively correlated with depression severity.

These medium- and long-chain acylcarnitine dysregulations argue for mitochondrial dysfunction through fatty acid β-oxidation impairment during major depression.

There is growing interest in using composite individualized treatment rules (ITRs) to guide depression treatment selection, but best approaches for doing this are not widely known. We develop an ITR for depression remission based on secondary analysis of a recently published trial for second-line antidepression medication selection using a cutting-edge ensemble machine learning method.

Data come from the SUN(^_^)D trial, an open-label, assessor blinded pragmatic trial of previously-untreated patients with major depressive disorder from 48 clinics in Japan. Initial clinic-level randomization assigned patients to 50 or 100 mg/day sertraline. We focus on the 1549 patients who failed to remit within 3 weeks and were then rerandomized at the individual-level to continuation with sertraline, switching to mirtazapine, or combining mirtazapine with sertraline. The outcome was remission 9 weeks post-baseline. Predictors included socio-demographics, clinical characteristics, baseline symptoms, changes in symptoms between baseline and week 3, and week 3 side effects.

Optimized treatment was associated with significantly increased cross-validated week 9 remission rates in both samples [5.3% (2.4%), p = 0.016 50 mg/day sample; 5.1% (2.7%), p = 0.031 100 mg/day sample] compared to randomization (30.1–30.8%). Optimization was also associated with significantly increased remission in both samples compared to continuation [24.7% in both: 11.2% (3.8%), p = 0.002 50 mg/day sample; 11.7% (3.9%), p = 0.001 100 mg/day sample]. Non-significant gains were found for optimization compared to switching or combining.

An ITR can be developed to improve second-line antidepressant selection, but replication in a larger study with more comprehensive baseline predictors might produce stronger and more stable results.

Nitric oxide synthase (NOS) activity, an enzyme potentially involved in the major depressive episodes (MDE), could be indirectly measured by the L-Citrulline/L-Arginine ratio (L-Cit/L-Arg). The aim of this study was: (1) to compare the NOS activity of patients with a MDE to that of healthy controls (HC); (2) to assess its change after antidepressant treatment.

A total of 460 patients with a current MDE in a context of major depressive disorder (MDD) were compared to 895 HC for NOS activity (L-Cit/L-Arg plasma ratio). L-Arg and L-Cit plasma levels were measured using a MS-based liquid chromatography method. Depressed patients were assessed at baseline, and after 3 and 6 months of antidepressant treatment for depression severity and clinical response.

Depressed patients had a lower NOS activity than HC at baseline [0.31 ± 0.09 v. 0.38 ± 0.12; 95% confidence interval (CI) −0.084 to −0.062, p < 0.0001]. Lower NOS activity at baseline predicted a higher response rate [odds ratio (OR) = 29.20; 95% CI 1.58–536.37; p = 0.023]. NOS activity in depressed patients increased significantly up to 0.34 ± 0.08 after antidepressant treatment (Est = 0.0034; 95% CI 0.0002–0.0067; p = 0.03).

Depressed patients have a decreased NOS activity that improves after antidepressant treatment and predicts drug response. NOS activity may be a promising biomarker for MDE in a context of MDD.

Structural neuroimaging studies have revealed a consistent pattern of volumetric reductions in both the hippocampus and the anterior cingulate cortex (ACC) of individuals with a major depressive episode (MDE). This study investigated hippocampal and ACC volume differences in the elderly comparing currently depressed individuals and individuals with a past lifetime history of MDE versus healthy controls.

We studied non-demented individuals from a cohort of community-dwelling people aged 65 and over (ESPRIT study). T1-weighted magnetic resonance images were used to acquire anatomical scans from 150 currently depressed individuals, 79 individuals with at least one past MDE, and 310 healthy controls. We derived quantitative regional estimates of subcortical volume of hippocampus and ACC using FreeSurfer Software (automated method). Concerning hippocampus, we also used a manual method of measurement. General Linear Model was used to study brain volumes in current and past depression adjusting for gender, age, education level, total brain volume, and anxiety disorder comorbidity.

After adjustment, current depression was associated with a lower left posterior hippocampal volume (F = 10.38, P = 0.001) using manual estimation of volume. No other significant differences were observed. A positive correlation was found between time since the last MDE and left posterior hippocampal volume.

The finding of left posterior hippocampal volume reduction in currently depressed individuals but not in those with a past MDE compared to healthy controls could be related to brain neuroplasticity. Additionally, our results suggest manual measures to be more sensitive than automated methods.

The authors have not supplied their declaration of competing interest.

Epidemiological, clinical, and treatment response characteristics of major depression with anxious distress (ADS) are quite similar to those of mixed depression, but no study investigated the symptom interplay of these conditions.

To analyze the correlations among symptom criteria for major depression with ADS and for mixed depression using a network analysis.

Two hundred and forty-one outpatients with major depression were consecutively recruited. DSM-5 criteria for major depression with ADS or with mixed features (MF) and Koukopoulos’ criteria for mixed depression (MXD) were assessed using a structured clinical interview.

A total of 58.9% of patients met DSM-5 criteria for major depression with ADS, 48.5% for MXD, and 2.5% for major depression with MF, so that the symptoms of this specifier were excluded from the network analysis. The most frequent symptoms were difficulty concentrating due to worries (57.7%), feeling keyed up or on edge (51%) (major depression with ADS), and psychic agitation or inner tension (51%) (MXD). Psychic agitation or inner tension had a central position in the network and bridged MXD to major depression with ADS through feeling keyed up or on edge.

Criteria for major depression with ADS and for MXD are partially overlapping, with psychic agitation or inner tension and feeling keyed up or on edge that feature in both conditions and are difficult to distinguish in clinical practice. The clarification of the relationship between these two psychopathological conditions could bring important implications for diagnosis, prognosis, and treatment of depressive episodes.

The brain-derived neurotrophic factor (BDNF) Val66Met polymorphism is associated with response to antidepressant drugs in depressed patients and with metabolic side effects after antipsychotic treatment. This study aims to assess the association between this polymorphism and insulin resistance after antidepressant treatment in depressed patients.

One hundred forty-eight Caucasian patients with a current unipolar major depressive episode (DSM IV-TR) were genotyped for the BDNF Val66Met polymorphism and assessed at baseline and after 3 and 6 months of antidepressant treatment for the ‘Homoeostasis model assessment of insulin resistance’ (HOMA-IR) index, a valid measure of insulin resistance based on fasting plasma insulinaemia and glycaemia. Because validity assumptions were fulfilled, data were analysed using analysis of variance for repeated measures.

The 52 (35%) Met carriers and 96 (65%) Val/Val patients were not different at baseline for clinical characteristics and HOMA-IR. A significant Val66Met × time interaction (p = 0.02), a significant time effect (p = 0.03) and a significant Val66Met effect (p = 0.0497) were shown for HOMA-IR. A significant Val66Met × time interaction (p = 0.01) and a significant time effect (p = 0.003) were shown for fasting glycaemia. HOMA-IR and fasting glycaemia changes after antidepressant treatment were significantly higher in Met carrier than in Val/Val patients (HOMA-IR changes: Met: 0.71 ± 3.29 v. Val/Val: −0.16 ± 1.34, t = 2.3, df = 146, p = 0.02, glycaemia changes: Met: 0.09 ± 0.30 v. Val/Val: 0.02 ± 0.16, t = −2.0, df = 146, p = 0.045).

The Met allele of the Val66Met BDNF polymorphism confers to depressed patients a higher risk of insulin-resistance after antidepressant treatment. These patients could benefit from specific monitoring of metabolism and preventive measures.

The stress sensitization theory hypothesizes that individuals exposed to childhood adversity will be more vulnerable to mental disorders from proximal stressors. We aimed to test this theory with respect to risk of 30-day major depressive episode (MDE) and generalized anxiety disorder (GAD) among new US Army soldiers.

The sample consisted of 30 436 new soldier recruits in the Army Study to Assess Risk and Resilience (Army STARRS). Generalized linear models were constructed, and additive interactions between childhood maltreatment profiles and level of 12-month stressful experiences on the risk of 30-day MDE and GAD were analyzed.

Stress sensitization was observed in models of past 30-day MDE (χ2 8 = 17.6, p = 0.025) and GAD (χ2 8 = 26.8, p = 0.001). This sensitization only occurred at high (3+) levels of reported 12-month stressful experiences. In pairwise comparisons for the risk of 30-day MDE, the risk difference between 3+ stressful experiences and no stressful experiences was significantly greater for all maltreatment profiles relative to No Maltreatment. Similar results were found with the risk for 30-day GAD with the exception of the risk difference for Episodic Emotional and Sexual Abuse, which did not differ statistically from No Maltreatment.

New soldiers are at an increased risk of 30-day MDE or GAD following recent stressful experiences if they were exposed to childhood maltreatment. Particularly in the military with an abundance of unique stressors, attempts to identify this population and improve stress management may be useful in the effort to reduce the risk of mental disorders.

The purpose of this paper is to describe variation, over the months of the year, in major depressive episode (MDE) prevalence. This is an important aspect of the epidemiological description of MDE, and one that has received surprisingly little attention in the literature. Evidence of seasonal variation in MDE prevalence has been weak and contradictory. Most studies have sought to estimate the prevalence of seasonal affective disorder using cut-points applied to scales assessing mood seasonality rather than MDE. This approach does not align with modern classification in which seasonal depression is a diagnostic subtype of major depression rather than a distinct category. Also, some studies may have lacked power to detect seasonal differences. We addressed these limitations by examining the month-specific occurrence of conventionally defined MDE and by pooling data from large epidemiological surveys to enhance precision in the analysis.

Data from two national survey programmes (the National Population Health Survey and the Canadian Community Health Survey) were used, providing ten datasets collected between 1996 and 2013, together including over 500,000. These studies assessed MDE using a short form version of the Composite International Diagnostic Interview (CIDI) for major depression, with one exception being a 2012 survey that used a non-abbreviated version of the CIDI. The proportion of episodes occurring in each month was evaluated using items from the diagnostic modules and statistical methods addressing complex design features of these trials. Overall month-specific pooled estimates and associated confidence intervals were estimated using random effects meta-analysis and a gradient was assessed using a meta-regression model that included a quadratic term.

There was considerable sampling variability when the month-specific proportions were estimated from individual survey datasets. However, across the various datasets, there was sufficient homogeneity to justify the pooling of these estimated proportions, producing large gains in precision. Seasonal variation was clearly evident in the pooled data. The highest proportion of episodes occurred in December, January and February and the lowest proportions occurred in June, July and August. The proportion of respondents reporting MDE in January was 70% higher than August, suggesting an association with implications for health policy. The pattern persisted with stratification for age group, sex and latitude.

Seasonal effects in MDE may have been obscured by small sample sizes in prior studies. In Canada, MDE has clear seasonal variation, yet this is not addressed in the planning of services. These results suggest that availability of depression treatment should be higher in the winter than the summer months.

Large community-based epidemiological surveys have consistently identified high co-morbidity between major depressive episode (MDE) and generalized anxiety disorder (GAD). Some have suggested that this co-morbidity may be artificial and the product of the current diagnostic system. Because of the added direct and indirect costs associated with co-morbidity, it is important to investigate whether methods of diagnostic classification are artificially increasing the level of observed co-morbidity.

The item response theory (IRT) log-likelihood ratio procedure was used to test for differential item functioning (DIF) of MDE symptoms between respondents with and without a diagnosis of GAD in the 2001–2002 National Epidemiological Survey on Alcohol and Related Conditions (NESARC).

The presence of GAD significantly increased the chances of reporting any symptom of MDE, with odds ratios ranging from 2.54 to 5.36. However, there was no indication of significant DIF of MDE symptoms in respondents with and without GAD.

The lack of any significant DIF indicates that cases with GAD do not present with a distinct MDE symptom profile, one that is consistent with the endorsement of symptoms that are conceptually similar in nature between the two disorders, compared to cases without GAD. This does not support the hypothesis that co-morbidity between MDE and GAD is artificially inflated because of the similar symptom criteria required by the current diagnostic system. Instead, MDE and GAD may be thought of as two distinct diagnostic entities that frequently co-occur because of a shared underlying trait.

Although generalized anxiety disorder (GAD) and major depressive episode (MDE) are known to be highly co-morbid, little prospective research has examined whether these two disorders predict the subsequent first onset or persistence of the other or the extent to which other predictors explain the time-lagged associations between GAD and MDE.

Data were analyzed from the nationally representative two-wave panel sample of 5001 respondents who participated in the 1990–1992 National Comorbidity Survey (NCS) and the 2001–2003 NCS follow-up survey. Both surveys assessed GAD and MDE. The baseline NCS also assessed three sets of risk factors that are considered here: childhood adversities, parental history of mental-substance disorders, and respondent personality.

Baseline MDE significantly predicted subsequent GAD onset but not persistence. Baseline GAD significantly predicted subsequent MDE onset and persistence. The associations of each disorder with the subsequent onset of the other attenuated with time since onset of the temporally primary disorder, but remained significant for over a decade after this onset. The risk factors predicted onset more than persistence. Meaningful variation was found in the strength and consistency of associations between risk factors and the two disorders. Controls for risk factors did not substantially reduce the net cross-lagged associations of the disorders with each other.

The existence of differences in risk factors for GAD and MDE argues against the view that the two disorders are merely different manifestations of a single underlying internalizing syndrome or that GAD is merely a prodrome, residual, or severity marker of MDE.