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Background and Objectives: Depression has been associated with alterations in social functioning. Decoding and understanding others' mental states and adaptive reasoning are important for social functioning. This study examined theory of mind (ToM) and socio-moral reasoning (SMR) in adolescent girls with and without depression. Within the depression group, we examined associations between relevant clinical features (depression severity, anxiety symptoms and borderline personality traits) and ToM and SMR.Methods: A cross-sectional study was conducted, whereby 43 adolescent girls (mean age = 16.19, SD = 1.24) meeting full or subthreshold criteria for depression and 40 adolescent girls (mean age = 15.44, SD = 1.24) with no psychiatric diagnosis were recruited. ToM was assessed using the Movie for the Assessment of Social Cognition; SMR was evaluated via the Socio-Moral Reasoning Aptitude Level task.Results: Analyses of covariance indicated that adolescents with depression did not differ from controls in ToM abilities but showed lower socio-maturity scores on the SMR task. This difference disappeared after controlling for the number of words used to justify responses. Amongst adolescents with depression, multiple linear regression analyses revealed that higher levels of borderline personality traits were associated with lower levels of mentalization (ToM task), and more severe depressive symptoms were associated with lower socio-moral maturity stages (SMR task) LIMITATIONS: Directional associations were not studied, and the sample included only girls.Conclusions: Findings may help to explain clinical heterogeneity in social cognitive functioning observed in individuals with depression. [ABSTRACT FROM AUTHOR]

The functioning of the hypothalamic-pituitary-adrenal (HPA) axis and serotonergic (5-HT) system are known to be intertwined with mood. Alterations in these systems are often associated with depression. However, neither are sufficient to cause depression in and of themselves. It is now becoming increasingly clear that the environment plays a crucial role, particularly, the perinatal environment. In this review, we posit that early environmental stress triggers a series of epigenetic mechanisms that adapt the genome and programme the HPA axis and 5-HT system for survival in a harsh environment. We focus on DNA methylation as it is the most stable epigenetic mark. Given that DNA methylation patterns are in large part set within the perinatal period, long-term gene expression programming by DNA methylation is especially vulnerable to environmental insults during this period. We discuss specific examples of genes in the 5-HT system (serotonin transporter) and HPA axis (glucocorticoid receptor and arginine vasopressin enhancer) whose DNA methylation state is associated with early life experience and may potentially lead to depression vulnerability. We conclude with a discussion on the relevance of studying epigenetic mechanisms in peripheral tissue as a proxy for those occurring in the human brain and suggest avenues for future research. [ABSTRACT FROM AUTHOR]

Negative affect in healthy populations regulates the appraisal of demanding situations, which tunes subsequent effort mobilization and adjustments in cognitive control. In the present study, we hypothesized that dysphoria in depressed individuals similarly modulates this adaptation, possibly through a neural mechanism involving serotonergic regulation. We tested the effect of dysphoria induced by acute tryptophan depletion (ATD) in remitted depressed patients on conflict adaptation in a Simon task. ATD temporarily lowers the availability of the serotonin precursor L-Tryptophan and is known to increase depressive symptoms in approximately half of remitted depressed participants. We found that depressive symptoms induced by ATD were associated with increased conflict adaptation. Our finding extends recent observations implying an important role of affect in regulating conflict-driven cognitive control. [ABSTRACT FROM AUTHOR]

Abstract: Acute tryptophan depletion (ATD) in currently depressed patients has no immediate effect on symptoms, but leads to transient symptom improvement or worsening the next day. In view of recent findings concerning the cognitive effects of serotonin manipulations, we used ATD in fourteen depressed patients to investigate whether cognitive effects following ATD predict symptom changes. We found that symptom improvement 24h after ATD was associated with an improved recall of positive words and with less attentional bias and recall of negative words, 5h after ATD. These results indicate that serotonergic alterations affect emotional processing which may subsequently lead to symptom changes. [Copyright &y& Elsevier]

Depressive disorders are associated with various cognitive impairments. Studies on whether or not these impairments persist into the euthymic phase have shown conflicting results, due to differences in test versions and in study samples. In this paper, we aimed to compare the cognitive performance of remitted depressed patients with that of age- and gender-matched healthy volunteers across a wide range of cognitive domains. In two studies, we found few differences on neutral as well as emotional information processing tests. The findings indicate that remitted depressed patients who use antidepressant medication still show an increased recognition of facial expression of fear compared to healthy controls. Patients also performed worse on a test of recognition of abstract visual information from long-term memory. No other residual cognitive impairments were found. These results indicate that most of the cognitive impairments associated with depression resolve with recovery through medication, even when recovery is incomplete. Considering the finding that remitted depressed patients have higher levels of cognitive reactivity, future studies may investigate the possibility that these cognitive impairments have not resolved but have become latent, and may therefore easily be triggered by small changes in mood state. Depression and Anxiety 0:1–10, 2007. © 2007 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Background: Depression is a major risk factor for cardiovascular disease. An important risk factor for cardiovascular disease, low heart rate variability, often has been found in depressed patients and has been associated with impulsivity. The present study investigated whether experimental lowering of serotonin would decrease heart rate variability and increase impulsivity in remitted depressed patients, in particular in those patients with disturbed impulse control. Methods: Nineteen patients in remission from depression received high-dose and low-dose acute tryptophan depletion in a randomized, counterbalanced, double-blind crossover design. Heart rate variability and impulsivity were assessed during each acute tryptophan depletion session and during a baseline session. Suicidal ideation during past depression was used as an index for individual differences in impulse control. Results: High-dose acute tryptophan depletion led to a larger increase in depressive symptoms than did low-dose acute tryptophan depletion. High-dose acute tryptophan depletion decreased heart rate variability and increased impulsivity and anxiety, but only in patients with a history of suicidal ideation. Symptom effects of high-dose acute tryptophan depletion correlated with low heart rate variability at baseline. Conclusions: Depressed patients who have problems with controlling impulsivity might be more at risk for developing cardiovascular disease, possibly related to increased vulnerability to impaired 5-hydroxytryptamine function. [Copyright &y& Elsevier]

Depression is associated with reduced brain serotonin (5-hydroxytryptamine; 5-HT) function and with cognitive dysfunctions. A diet rich in α-lactalbumin protein has been found to increase the ratio tryptophan/large neutral amino acids (Trp/∑LNAA), and to improve cognitive functioning in individuals with high neuroticism scores. Since cognitive dysfunctions sometimes persist after remission of depression, the present study investigated the effects of α-lactalbumin-enriched diet on cognition in recovered depressed patients. Twenty-three recovered depressed patients and 20 healthy matched controls without a history of depression consumed meals rich in α-lactalbumin or casein protein in a double-blind crossover design. Mood, cognitive function and plasma amino acids were assessed at both sessions before and after dietary intake. Alpha-lactalbumin protein had no effect on mood, but improved abstract visual memory and impaired simple motor performance. These effects were independent of history of depression. Supplements of α-lactalbumin may be useful for nutrition research in relation to age- or disease-related memory decline. The present findings should be further examined in different (e.g. medicated) samples. The long-term effects of α-lactalbumin should also be investigated. [ABSTRACT FROM AUTHOR]

Abstract: Background: It has frequently been demonstrated that experimental lowering of serotonin (5-HT) neurotransmission by acute tryptophan depletion (ATD) induces a transient depressed mood in 50–60% of patients treated with a selective serotonin reuptake inhibitor (SSRI) who are in remission from depression. In unmedicated depressed patients, ATD has no immediate effect on symptoms. The effects in currently depressed medicated patients have not been investigated. Methods: Fourteen currently depressed patients (seven patients treated with a selective serotonin–noradrenalin reuptake inhibitor (SSNRI); seven other treatment, non-SSNRI) received ATD in a double-blind, crossover design. Different strengths of the ATD mixture (aimed at 50% and 90% reduction of tryptophan) were used on separate days. Psychiatric symptoms were assessed at both sessions prior to, at +6.5 h, and at +24 h after ATD. Results: The ATD mixtures induced the expected reductions of plasma tryptophan levels. Full but not partial depletion improved mood and other psychiatric symptoms at +24 h in patients who received SSNRI treatment, as indicated by clinical ratings and self-report. Subjective sleep quality also improved. Conclusions: The effects of ATD on psychiatric symptoms in currently depressed patients are remarkably different from the results in recently remitted SSRI-treated patients. ATD in currently depressed patients treated with serotonergic antidepressants possibly provides important information about the mechanism of action of SSRIs. [Copyright &y& Elsevier]

It has frequently been demonstrated that acute tryptophan depletion (ATD) induces a transient depressed mood in some patients who are in remission from depression. However, the effects of ATD on cognitive processes in remitted depressed patients have not been investigated. The aim of the present study was to investigate the effects of different extents of depletion on mood and cognitive tasks involving neutral and emotional stimuli. Twenty patients in remission or in partial remission from depression received ATD in a double-blind, crossover design. Mood was assessed at both sessions before, at +6.5 h and +24 h after depletion. Cognitive assessment in both sessions started at +4.75 h, and also before and after the whore procedure. The ATD mixtures induced the expected reductions of plasma tryptophan levels. High-dose ATD induced a depressive response in a subsample of patients and impaired the processing of positive information independent of mood change. Attention for neutral stimuli (Stroop interference) improved in a dose-dependent manner. ATD may affect mood and cognition via different pathways: one implicated in mood regulation and the processing of emotional information, and one for the processing of neutral information. The first pathway may be more important for discriminating vulnerability to impaired serotonin function. The comparison of the effects of high-dose and low-dose ATD is useful for those studies aiming to investigate the relationships among 5-HT, mood and cognition. [ABSTRACT FROM AUTHOR]

Acute tryptophan depletion (ATD) induces depressive symptoms in 50-60% of selective serotonin reuptake inhibitor (SSRI) treated, recovered depressed patients. However, no reliable predictors of mood response to ATD have been established. In the present study, individual subject data of six ATD studies were pooled (‘mega-analysis’) in order to investigate the mediating role of clinical, demographic and biochemical characteristics in the mood response to ATD. A procedure was developed to make different versions of the Hamilton scale comparable. Recurrent depressive episodes, female gender, prior exposure to SSRI antidepressant treatment and previous serious suicidal thoughts/attempts all appear to be independent predictors of mood response to ATD. Chronicity of illness is the most powerful predictor. Residual symptoms of depression were not found to predict response to ATD. ATD may be useful to study the mechanism of action of SSRI antidepressants and individual biological vulnerability of the serotonin system. Whether the effects of ATD represent a reversal of the action of SSRI antidepressants or individual vulnerability probably depends upon the timing of the procedure in the course of remission of a depressive episode. [Copyright &y& Elsevier]

• Adolescents with depression were marginally faster than those in the comparison group to recognise sadness, although this trend disappeared once covarying for age and use of antidepressant medication. • Within the depression group, severity of depression symptoms and borderline personality features were associated with poorer emotional facial expression recognition (EFER) performance. • Discrepancies between group and within-group differences may explain some of the clinical heterogeneity observed in studies of EFER amongst adolescents with depression. • Studying clinical features in relation to EFER in adolescents with depression allows for a more nuanced understanding of social difficulties that may be experienced in depression. Studies have reported that emotional facial expression recognition (EFER) may be altered in individuals with depression. This study examined EFER in adolescent girls with and without depression and further examined associations between relevant clinical features of depression and EFER. Fifty adolescent girls aged 12 to 19 years old meeting criteria for depression or subthreshold levels of symptomatology and 55 adolescent girls with no psychiatric diagnosis completed EFER tasks. Reaction time and accuracy for recognising expressions at high and low intensities, and sensitivity in recognising happiness, sadness, anger and fear were assessed. Data were analysed using linear mixed models. Adolescents with depression were marginally faster than those in the comparison group to recognize sadness, although this trend disappeared once covarying for age and antidepressant use. Amongst adolescents with depression, clinical features were associated with poorer EFER performance. In contrast, anxiety symptoms were linked to better accuracy and heightened sensitivity towards happiness. A better understanding of EFER in adolescent girls with and without depression, and how clinical features might be associated with altered patterns of EFER could help to explain clinical heterogeneity observed in such studies of adolescents with depression. Knowledge of socio-cognitive alterations associated with depression will help to better develop and tailor interventions. [ABSTRACT FROM AUTHOR]

Background: Acute tryptophan depletion (ATD) induces depressive symptoms in remitted depressed patients treated with serotonergic medications, but not in patients treated with noradrenergic medications or electroconvulsive therapy. A recent study suggests that cognitive therapy (CT) protects against the effects of ATD, but the evidence is questionable. The present study compared the effect of ATD in patients who were treated with antidepressant medication and CT (n = 17) versus antidepressant medication alone (n = 23) during their latest episode. Methods: Forty remitted depressed patients underwent high-dose and low-dose ATD in a randomized double-blind crossover design. Results: There were no differences in response to ATD between treatment groups. This applied to groups defined by lifetime and by recent CT experience. Conclusions: Cognitive therapy does not protect against the effects of rapidly lowered plasma tryptophan levels in remitted depressed patients who are also treated with antidepressant medication. [Copyright &y& Elsevier]

Background: Disrupted sleep quality is one of the proposed mechanisms through which chronic stress may lead to depression. However, there exist significant individual differences in sleep reactivity, which is the extent to which one experiences sleep disturbances in response to stress.Purpose: The aim of the current study was to investigate whether low high-frequency heart rate variability (HRV), as a psychophysiological marker of poor emotional and physiological arousal regulation, predicts stress-related sleep disturbances associated with greater risk of depression symptoms.Methods: Using a chronic caregiving stress model, 125 mothers of adolescents with developmental disorders and 97 mothers of typically developing adolescents had their resting HRV and HRV reactivity recorded and completed a measure of depressive symptoms, as well as a 7 day sleep diary to assess their sleep quality. A moderated mediation model tested whether sleep quality mediated the association between chronic stress exposure and depressive symptoms and whether HRV moderated this mediation.Results: After controlling for participant age, body mass index, ethnicity, socioeconomic status, and employment status, poor sleep quality mediated the association between chronic stress and depressive symptoms. Resting HRV moderated this indirect effect such that individuals with lower HRV were more likely to report poorer sleep quality in the context of chronic stressor exposure, which, in turn, was related to greater depressive symptoms.Conclusions: Lower HRV, a potential biomarker of increased sleep reactivity to stress, is associated with greater vulnerability to stress-related sleep disturbances, which, in turn, increases the risk for elevated depressive symptoms in response to chronic stress. [ABSTRACT FROM AUTHOR]

Objectives: Accurate and complete study reporting allows evidence users to critically appraise studies, evaluate possible bias, and assess generalizability and applicability. We evaluated the extent to which recent studies on depression screening accuracy were reported consistent with Standards for Reporting of Diagnostic Accuracy Studies (STARD) statement requirements. Methods: MEDLINE was searched from January 1, 2018 through May 21, 2021 for depression screening accuracy studies. Results: 106 studies were included. Of 34 STARD items or sub‐items, the number of adequately reported items per study ranged from 7 to 18 (mean = 11.5, standard deviation [SD] = 2.5; median = 11.5), and the number inadequately reported ranged from 3 to 17 (mean = 10.1, SD = 2.5; median = 10.0). There were eight items adequately reported, seven partially reported, 11 inadequately reported, and four not applicable in ≥50% of studies; the remaining four items had mixed reporting. Items inadequately reported in ≥70% of studies related to the rationale for index test cut‐offs examined, missing data management, analyses of variability in accuracy results, sample size determination, participant flow, study registration, and study protocol. Conclusion: Recently published depression screening accuracy studies are not optimally reported. Journals should endorse and implement STARD adherence. [ABSTRACT FROM AUTHOR]

Objectives: Depression screening tool accuracy studies should be conducted with large enough sample sizes to generate precise accuracy estimates. We assessed the proportion of recently published depression screening tool diagnostic accuracy studies that reported sample size calculations; the proportion that provided confidence intervals (CIs); and precision, based on the width and lower bounds of 95% CIs for sensitivity and specificity. In addition, we assessed whether these results have improved since a previous review of studies published in 2013–2015. Methods: MEDLINE was searched from January 1, 2018, through May 21, 2021. Results: Twelve of 106 primary studies (11%) described a viable sample size calculation, which represented an improvement of 8% since the last review. Thirty‐six studies (34%) provided reasonably accurate CIs. Of 103 studies where 95% CIs were provided or could be calculated, seven (7%) had sensitivity CI widths of ≤10%, whereas 58 (56%) had widths of ≥21%. Eighty‐four studies (82%) had lower bounds of CIs <80% for sensitivity and 77 studies (75%) for specificity. These results were similar to those reported previously. Conclusion: Few studies reported sample size calculations, and the number of included individuals in most studies was too small to generate reasonably precise accuracy estimates. [ABSTRACT FROM AUTHOR]

Screening is done to improve health outcomes by identifying and effectively treating individuals with unrecognized conditions. Depression screening has been proposed to identify previously unrecognized depression cases. Including individuals already diagnosed or treated for depression in screening test accuracy studies could exaggerate accuracy and the yield of new cases from screening. The present study investigated (1) the proportion of depression screening tool accuracy primary studies published in 2018–2021 that excluded individuals with a confirmed depression diagnosis or who were already undergoing treatment; and (2) whether this has improved since the last review of studies published in 2013–2015, which found that five of 89 (5.6%) primary studies appropriately excluded such individuals. MEDLINE was searched from January 1, 2018 through May 21, 2021 for primary studies on depression screening tool accuracy. Eighteen of 106 (17.0%; 95% Confidence Interval [CI], 11.0% to 25.3%) primary studies excluded currently diagnosed or treated individuals. This was 11.4% (95% CI, 2.8% to 20.0%) greater than in similar studies published in 2013–2015. There has been an improvement since 2015, but the proportion of studies that exclude individuals already known to have depression remains low. This may bias research findings intended to inform clinical practice. [ABSTRACT FROM AUTHOR]

Tryptophan hydroxylase 2 (TPH2) is the rate-limiting enzyme in brain serotonin synthesis. The TPH2 gene has frequently been investigated in relation to psychiatric morbidity. The aim of the present review is to integrate results from association studies between TPH2 single nucleotide polymorphisms (SNPs) and various psychiatric disorders, which we furthermore quantified with meta-analysis. We reviewed 166 studies investigating 69 TPH2 SNPs in a broad range of psychiatric disorders, including over 30,000 patients. According to our meta-analysis, TPH2 polymorphisms show strongest associations with mood disorders, suicide (attempt) and schizophrenia. Despite small effect sizes, we conclude that TPH2 SNPs in the coding and non-coding areas (rs4570625, rs11178997, rs11178998, rs10748185, rs1843809, rs4290270, rs17110747) are each associated with one or more psychopathological conditions. Our findings highlight the possible common serotonergic mechanisms of the investigated psychiatric disorders. Yet, the functional relevance of most TPH2 polymorphisms is unclear. Characterizing how exactly the different TPH2 variants influence the serotonergic neurotransmission is a next necessary step in understanding the psychiatric disorders where serotonin is implicated. [ABSTRACT FROM AUTHOR]

Depression is associated with alterations in hypothalamic–pituitary–adrenal (HPA) axis activity. A proposed mechanism to explain these alterations are changes in DNA methylation levels, secondary to early life adversity (ELA), at stress-related genes. Two gene regions that have been implicated in the literature, the glucocorticoid receptor gene ( NR3C1 ) exon 1F and the FKBP5 gene intron 7 were examined in 67 individuals (33 depressed patients and 34 controls). We investigated whether cortisol concentrations, evaluated in 25 depressed patients and 20 controls, and measures of ELA were associated with the degree of methylation at these candidate gene regions. Mean NR3C1 exon 1F DNA methylation levels were significantly increased in the depressed cohort and the degree of methylation was found to be positively associated with morning cortisol concentrations. DNA methylation levels at specific CG sites within the NR3C1 exon 1F were related to childhood emotional abuse severity. DNA methylation at CG38 was related to both HPA axis and childhood emotional abuse measures in the depressed group. No FKBP5 differences were revealed. Our findings suggest that hypermethylation at the NR3C1 exon 1F may occur in depression. This locus-specific epigenetic change is associated with higher basal HPA axis activity, possibly reflecting acquired glucocorticoid receptor resistance. [ABSTRACT FROM AUTHOR]

Background: Difficult temperament in infancy is a risk factor for forms of later internalizing and externalizing psychopathology, including depression and anxiety. A better understanding of the roots of difficult temperament requires assessment of its early development with a genetically informative design. The goal of this study was to estimate genetic and environmental contributions to individual differences in infant negative emotionality, their persistence over time and their influences on stability between 5 and 18 months of age. Method: Participants were 244 monozygotic and 394 dizygotic twin pairs (49.7% male) recruited from birth. Mothers rated their twins for negative emotionality at 5 and 18 months. Longitudinal analysis of stability and innovation between the two time points was performed in Mplus. Results: There were substantial and similar heritability (approximately 31%) and shared environmental (57.3%) contributions to negative emotionality at both 5 and 18 months. The trait’s interindividual stability across time was both genetically- and environmentally- mediated. Evidence of innovative effects (i.e., variance at 18 months independent from variance at 5 months) indicated that negative emotionality is developmentally dynamic and affected by persistent and new genetic and environmental factors at 18 months. Conclusions: In the first two years of life, ongoing genetic and environmental influences support temperamental negative emotionality but new genetic and environmental factors also indicate dynamic change of those factors across time. A better understanding of the source and timing of factors on temperament in early development, and role of sex, could improve efforts to prevent related psychopathology. [ABSTRACT FROM AUTHOR]