Life stress and the long-term treatment course of recurrent depression: III. Nonsevere life events predict recurrence for medicated patients over 3 years

Financial strain and depression in the U.S.: a scoping review

While the association between assets and depression has been established, less is known about the link between financial strain and depression. Given rising financial strain and economic inequity due to the COVID-19 pandemic, understanding the role that financial strain plays in shaping population depression in the United States is particularly salient. We conducted a scoping review of the peer-reviewed literature on financial strain and depression published from inception through January 19, 2023, in Embase, Medline via PubMed, and PsycINFO, PsycArticles, SocINDEX, and EconLit via Ebsco. We searched, reviewed, and synthesized the literature on longitudinal studies on financial strain and depression conducted in the United States. Four thousand and four unique citations were screened for eligibility. Fifty-eight longitudinal, quantitative articles on adults in the United States were included in the review. Eighty-three percent of articles (n = 48) reported a significant, positive association between financial strain and depression. Eight articles reported mixed results, featuring non-significant associations for some sub-groups and significant associations for others, one article was unclear, and one article reported no significant association between financial strain and depression. Five articles featured interventions to reduce depressive symptoms. Effective interventions included coping mechanisms to improve one's financial situation (e.g., mechanisms to assist in finding employment), to modify cognitive behavior (e.g., reframing mindset), and to engage support (e.g., engaging social and community support). Successful interventions were tailored to participants, were group-based (e.g., they included family members or other job seekers), and occurred over multiple sessions. While depression was defined consistently, financial strain was defined variably. Gaps in the literature included studies featuring Asian populations in the United States and interventions to reduce financial strain. There is a consistent, positive association between financial strain and depression in the United States. More research is needed to identify and test interventions that mitigate the ill effects of financial strain on population's mental health.

Is it worth turning a trigger into a joke? Humor as an emotion regulation strategy in remitted depression

AIM

Humor has long been considered as an effective emotion regulation strategy for people vulnerable to depression, but empirical evidence in this area is scarce. To address this issue, we investigated the emotional consequences of humor in remitted depressed patients and compared them with the effects of positive reappraisal and spontaneous emotion regulation.

METHODS

Fifty-five patients with remitted major depression took part in a laboratory computer experiment in which they were shown negative pictures twice. First, the patients simply viewed the pictures and rated their reactions. Second, they viewed each of the pictures according to instructions, which are to (a) use humor, (b) use positive reappraisal, or (c) simply view the pictures, and then, they again rated their reactions.

RESULTS

Humor was found to decrease negative emotions, increase positive emotions, and enhance the distance from adversity; it was more effective than spontaneous emotion regulation and similarly as effective as positive reappraisal. Humor was the most effortful form of emotion regulation. Patients were able to successfully produce humorous comments, and their failure to do so did not lead to worse emotional outcomes than regulating emotions spontaneously. The analyses also indicated that distancing mediates between using humor and the intensity of positive and negative emotions.

CONCLUSIONS

Our findings provide preliminary empirical support for the idea that for individuals vulnerable to depression, humor can be an adaptive tool in dealing with negative responses to aversive events, and, thus, it may impair their potential of these events to trigger depressive episodes. Further studies in this area are warranted to determine the most adaptive forms of humor and analyze their effects in various depressogenic contexts.

Association between acute critical life events and the speed of onset of depressive episodes in male and female depressed patients

BACKGROUND

A series of studies indicate that a fast onset of a depressive episode (within 7 days) is a clinical variable useful for indicating bipolarity even when no manic episode has occurred to date. The role of acute critical life events as an external trigger for a fast onset of the depression is unclear so far. Therefore, aim of this investigation was to analyse the effects of acute critical life events on the speed of onset of depressive episodes.

METHODS

Speed of onset of depression was assessed using the patient interview "Onset of Depression Inventory". Acute critical life events occurring within the last 6 months before the onset of first depressive symptoms were assessed using the Munich Interview for the Assessment of Life Events and Conditions.

RESULTS

96 of 100 (96.0%) patients had at least one acute critical life event within six months prior to first symptoms of a depressive episode. 22 patients (22.0%) had a fast onset of depression (≤ 7 days). Faster onset of the current depressive episode was significantly associated with a higher number of acute minor life events (β = - 0.23; p = 0.02), but overall fast onset of a depressive episode was not significantly associated with more acute critical life events in the six months before the onset of the depression. The association between the number of acute critical life events in the half-year period preceding the onset of unipolar depressive disorders and speed of onset for the current depressive episode was neither dependent from gender nor the presence of prior depressive episodes.

CONCLUSIONS

Speed of onset of depression is not strongly influenced by external trigger e.g. acute critical life events.

Do Life Events and Social Support Vary across Depressive Disorders?

BACKGROUND

Social support and life events moderate the expression of depression though studies have shown contradictory results. The objective was to study the stressful life events and perceived social support in patients with adjustment disorder, first-episode depression, and recurrent depressive disorder (RDD).

SUBJECTS AND METHODS

One hundred and forty-six patients aged 18-60 years with adjustment disorder, first-episode depression, or RDD according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision were evaluated using the presumptive stressful life events scale and Multidimensional Scale of Perceived Social Support.

RESULTS

There was no difference in mean number of total life events and subgroups as well as perceived stress score in the past 1 year between the groups. There was no difference in the perceived social support scale total score, as well as from family and friends, across the three groups. However, the mean perceived social support from significant others in those with RDD was lower as compared to those with adjustment disorder.

CONCLUSION

Stressful life events do not differ in adjustment disorder, first-episode depression, and RDD. Furthermore, the perceived social support was similar across the three groups, except for perceived social support from significant others, which was less in those with RDD.

Trajectories of relapse in randomised, placebo-controlled trials of treatment discontinuation in major depressive disorder: an individual patient-level data meta-analysis

BACKGROUND

Understanding patterns of relapse in patients who respond to antidepressant treatment can inform strategies for prevention of relapse. We aimed to identify distinct trajectories of depression severity, assess whether similar or different trajectory classes exist for patients who continued or discontinued active treatment, and test whether clinical predictors of trajectory class membership exist using pooled data from clinical trials.

METHODS

We analysed individual patient data from four double-blind discontinuation clinical trials of duloxetine or fluoxetine versus placebo in major depression from before 2012 (n=1462). We modelled trajectories of relapse up to 26 weeks during double-blind treatment. Trajectories of depression severity, as measured by the Hamilton Depression Rating Scale score, were identified in the entire sample, and separately in groups in which antidepressants had been continued or discontinued, using growth mixture models. Predictors of trajectory class membership were assessed with weighted logistic regression.

FINDINGS

We identified similar relapse trajectories and two trajectories of stable depression scores in the normal range on active medication and on placebo. Active treatment significantly lowered the odds of membership in the relapse trajectory (odds ratio 0·47, 95% CI 0·37-0·61), whereas female sex (1·56, 1·23-2·06), shorter length of time with clinical response by 1 week (1·10, 1·06-1·15), and higher Clinical Global Impression score at baseline (1·28, 1·01-1·62) increased the odds. Overall, the protective effect of antidepressant medication relative to placebo on the risk of being classified as a relapser was about 13% (33% vs 46%).

INTERPRETATION

The existence of similar relapse trajectories on active medication and on placebo suggests that there is no specific relapse signature associated with antidepressant discontinuation. Furthermore, continued treatment offers only modest protection against relapse. These data highlight the need to incorporate treatment strategies that prevent relapse as part of the treatment of depression.

FUNDING

National Institutes of Health, the US Department of Veterans Affairs Alcohol Research Center, and National Center for Post-Traumatic Stress Disorder.

Relationships among Stress, Experiential Avoidance and Depression in Psychiatric Patients

This study investigated the specific association of stressful life events (SLE) and experiential avoidance (EA) with depression in patients with mental disorders. It also analyzed the possible mediating role of depression in the relation of EA to well-being and life satisfaction. A total of 147 patients (mean age = 40.16 years) diagnosed with anxiety, mood or adjustment disorder were recruited from a mental health centre. They completed measures of SLE, EA, depression, well-being and life satisfaction. Regression analyses showed that SLE and EA were positively related to depression (R 2 = .45), although the contribution made by EA was higher (β = .61, p < .001) than the one made by SLE (β = .19, p < .01). Bootstrap mediation analyses revealed that there was an indirect effect from EA to physical well-being (B = -4.52, SE = .70, p < .001, 95% CI [-6.03, -3.20]) and satisfaction (B = -.14, SE = .02, p < .001, 95%, CI [-.19 -.09]) through depression. This indirect effect was less consistently supported with respect to emotional well-being (B = -3.33, SE = .48, p < .001, 95%, CI [-4.30, -2.41]). These findings give support to the hypothesis that EA could be an important factor contributing to depression in patients with mental disorders. The results also provide evidence that depression seems to play an important mediational role when considering the negative impact that EA exerts on patients´ well-being and satisfaction.

Influences of Chronic Mild Stress Exposure on Motor, Non-Motor Impairments and Neurochemical Variables in Specific Brain Areas of MPTP/Probenecid Induced Neurotoxicity in Mice

Parkinson's disease (PD) is regarded as a movement disorder mainly affecting the elderly population and occurs due to progressive loss of dopaminergic (DAergic) neurons in nigrostriatal pathway. Patients suffer from non-motor symptoms (NMS) such as depression, anxiety, fatigue and sleep disorders, which are not well focussed in PD research. Depression in PD is a predominant /complex symptom and its pathology lies exterior to the nigrostriatal system. The main aim of this study is to explore the causative or progressive effect of chronic mild stress (CMS), a paradigm developed as an animal model of depression in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (25 mg/kg. body wt.) with probenecid (250 mg/kg, s.c.) (MPTP/p) induced mice model of PD. After ten i.p. injections (once in 3.5 days for 5 weeks) of MPTP/p or exposure to CMS for 4 weeks, the behavioural (motor and non-motor) impairments, levels and expressions of dopamine (DA), serotonin (5-HT), DAergic markers such as tyrosine hydroxylase (TH), dopamine transporter (DAT), vesicular monoamine transporters-2 (VMAT 2) and α-synuclein in nigrostriatal (striatum (ST) and substantia nigra (SN)) and extra-nigrostriatal (hippocampus, cortex and cerebellum) tissues were analysed. Significantly decreased DA and 5-HT levels, TH, DAT and VMAT 2 expressions and increased motor deficits, anhedonia-like behaviour and α-synuclein expression were found in MPTP/p treated mice. Pre and/or post exposure of CMS to MPTP/p mice further enhanced the MPTP/p induced DA and 5-HT depletion, behaviour abnormalities and protein expressions. Our results could strongly confirm that the exposure of stress after MPTP/p injections worsens the symptoms and neurochemicals status of PD.

Chronic and episodic interpersonal stress as statistically unique predictors of depression in two samples of emerging adults

Few studies comprehensively evaluate which types of life stress are most strongly associated with depressive episode onsets, over and above other forms of stress, and comparisons between acute and chronic stress are particularly lacking. Past research implicates major (moderate to severe) stressful life events (SLEs), and to a lesser extent, interpersonal forms of stress; research conflicts on whether dependent or independent SLEs are more potent, but theory favors dependent SLEs. The present study used 5 years of annual diagnostic and life stress interviews of chronic stress and SLEs from 2 separate samples (Sample 1 N = 432; Sample 2 N = 146) transitioning into emerging adulthood; 1 sample also collected early adversity interviews. Multivariate analyses simultaneously examined multiple forms of life stress to test hypotheses that all major SLEs, then particularly interpersonal forms of stress, and then dependent SLEs would contribute unique variance to major depressive episode (MDE) onsets. Person-month survival analysis consistently implicated chronic interpersonal stress and major interpersonal SLEs as statistically unique predictors of risk for MDE onset. In addition, follow-up analyses demonstrated temporal precedence for chronic stress; tested differences by gender; showed that recent chronic stress mediates the relationship between adolescent adversity and later MDE onsets; and revealed interactions of several forms of stress with socioeconomic status (SES). Specifically, as SES declined, there was an increasing role for noninterpersonal chronic stress and noninterpersonal major SLEs, coupled with a decreasing role for interpersonal chronic stress. Implications for future etiological research were discussed.

Dopamine Receptor D2 and Associated microRNAs Are Involved in Stress Susceptibility and Resistance to Escitalopram Treatment

BACKGROUND

Early life stress has been demonstrated to increase the risk of developing depression in adulthood. However, the roles and associated molecular mechanisms of stresses in the onset and relapse of depression have yet to be fully elucidated.

METHODS

Depression-like behaviors were induced in rats by maternal deprivation and chronic unpredictable stress. Depression- and anxiety-like behaviors of rats, dopamine receptor D2 level, and microRNAs expression in rats' brain tissues were measured.

RESULTS

Chronic unpredictable stress alone induced depression-like behaviors in rats, but maternal deprivation enhanced the effect of chronic unpredictable stress. Escitalopram significantly decreased depression-like behaviors in chronic unpredictable stress rats but was less effective in maternal deprivation with chronic unpredictable stress rats. Maternal deprivation increased dopamine receptor D2 messenger RNA expression and decreased microRNA-9 expression in the striatum. Chronic unpredictable stress increased dopamine receptor D2 mRNA and protein levels and decreased microRNA-9 expression in the nucleus accumbens. Furthermore, maternal deprivation enhanced the effect of chronic unpredictable stress on dopamine receptor D2 gene and microRNA-9 expression. Chronic unpredictable stress increased the expression of microRNA-326 in the nucleus accumbens but decreased it in the striatum, whereas maternal deprivation elevated microRNA-326 expression in the striatum. Escitalopram normalized microRNA-326 expression but had no effect on the expression of microRNA-9, dopamine receptor D2 mRNA, and dopamine receptor D2 protein in both the nucleus accumbens and striatum. The in vitro study showed that only microRNA-9 directly targeted the 3' untranslated region of dopamine receptor D2 mRNA and inhibited dopamine receptor D2 protein expression.

CONCLUSION

Early life stress enhanced the susceptibility to late life stress and resistance to escitalopram treatment through decreasing microRNA-9 expression and subsequently upregulating dopamine receptor D2 expression in the nucleus accumbens. microRNA-326 may be a novel target of escitalopram.

A two-factor model of relapse/recurrence vulnerability in unipolar depression

The substantial health burden associated with major depressive disorder (MDD) is a product of both its high prevalence and the significant risk of relapse, recurrence, and chronicity. Establishing recurrence vulnerability factors (VFs) could improve the long-term management of MDD by identifying the need for further intervention in seemingly recovered patients. We present a model of sensitization in depression vulnerability, with an emphasis on the integration of behavioral and neural systems accounts. Evidence suggests that VFs fall into 2 categories: dysphoric attention and dysphoric elaboration. Dysphoric attention is driven by fixation on negative life events, and is characterized behaviorally by reduced executive control, and neurally by elevated activity in the brain's salience network. Dysphoric elaboration is driven by rumination that promotes overgeneral self- and contextual appraisals, and is characterized behaviorally by dysfunctional attitudes, and neurally by elevated connectivity within normally distinct prefrontal brain networks. Although few prospective VF studies exist from which to catalogue a definitive neurobehavioral account, extant data support the value of the proposed 2-factor model. Measuring the continued presence of these 2 VFs during recovery may more accurately identify remitted patients who would benefit from targeted prophylactic intervention.

The scars of childhood adversity: minor stress sensitivity and depressive symptoms in remitted recurrently depressed adult patients

Background

Childhood adversity may lead to depressive relapse through its long-lasting influence on stress sensitivity. In line with the stress sensitization hypothesis, minor (daily) stress is associated with depressive relapse. Therefore, we examine the impact of childhood adversity on daily stress and its predictive value on prospectively assessed depressive symptoms in recurrently depressed patients.

Method

Daily stress was assessed in recurrently depressed adult patients, enrolled into two randomized trials while remitted. The reported intensity and frequency of dependent and independent daily stress was assessed at baseline. Independent stress is externally generated, for example an accident happening to a friend, while dependent stress is internally generated, for example getting into a fight with a neighbor. Hierarchical regression analyses were performed with childhood adversity, independent and dependent daily stress as predictor variables of prospectively measured depressive symptoms after three months of follow-up (n = 138).

Results

We found that childhood adversity was not significantly associated with a higher frequency and intensity of daily stress. The intensity of both independent and dependent daily stress was predictive of depressive symptom levels at follow-up (unadjusted models respectively: B = 0.47, t = 2.05, p = 0.041, 95% CI = 0.02–0.92; B = 0.29, t = 2.20, p = 0.028, 95% CI = 0.03–0.55). No associations were found between childhood adversity and depressive symptoms at follow-up.

Conclusion

No evidence was found supporting stress sensitization due to the experience of childhood adversity in this recurrently depressed but remitted patient group. Nevertheless, our research indicates that daily stress might be a target for preventive treatment.

Trial Registration

Trial A: Nederlands Trial Register NTR1907 Trial B: Nederlands Trial Register NTR2503

Influence of genetic polymorphisms involved in the hypothalamic-pituitary-adrenal axis and their interactions with environmental factors on antidepressant response

AIMS

To investigate the role of genetic polymorphisms in candidate genes associated with the HPA axis and their interactions with environmental stressors in antidepressant response.

METHODS

The remission of depressive symptoms after 8 weeks of antidepressant treatment was tested against 21 single nucleotide polymorphisms (SNPs) in five candidate genes associated with the HPA axis in a Chinese Han sample suffering from unipolar depression (n = 273). Any history of childhood trauma and recent negative life events were measured using the Childhood Trauma Questionnaire-Short Form (CTQ-SF) (n = 206) and the Life Event Scale (48 item, LES) (n = 207), respectively. Reporter gene assays were used to evaluate the possible effects of the most significant SNP on gene expression.

RESULTS

A functional polymorphism at 3'UTR of the corticotropin-releasing hormone receptor 1 (CRHR1) gene (rs28364032) and three haplotypes containing it showed significant relationships with antidepressant remission. Further laboratory-based genomic studies showed that the G-to-A change of rs28364032 resulted in a 10-12% decrease in the intensity of luciferase activity. However, we failed to find association of environments and their interaction with HPA system-related genes with antidepressant remission.

CONCLUSIONS

Our results support a definite role for CRHR1 in the pharmacogenetics of antidepressant drugs. This may contribute to interpatient differences in their responses to antidepressant drugs.

Acute and chronic stress exposure predicts 1-year recurrence in adult outpatients with residual depression symptoms following response to treatment

BACKGROUND

One of the strongest predictors of depression recurrence in those who respond to treatment is the presence of residual depressive symptoms. Our goal was to examine stressful life event exposure as a mechanism of recurrence in previously depressed patients with residual depression symptoms. That is, we predicted that higher levels of residual symptoms will significantly predict exposure to acute life events that will then heighten prospective recurrence risk.

METHODS

Participants included 68 adult outpatients with major depression (42 women; age 18-60) who completed a 12-month naturalistic follow-up after achieving remission in a 20-week randomized, open label trial of interpersonal psychotherapy, cognitive-behavioral therapy, or antidepressant medication. Depression recurrence was defined as the reemergence of an episode of major depression as determined by structured interview. Acute life events and chronic stressors were assessed at the end of follow-up using a contextual interview.

RESULTS

Posttreatment depression scores significantly prospectively predicted an increased risk for recurrence, and acute life events in the follow-up period. Cox regression survival analyses modeling life events as time-dependent covariates showed that life event exposure mediated the relation of residual symptoms to recurrence even controlling for chronic stress.

CONCLUSIONS

Our findings implicate residual symptoms in heightening depression recurrence risk through exposure to stressful life events. Depression recurrence adds significantly to the burden of the disorder. Therefore, rigorous follow-up of patients targeting the stressful context has the potential to prevent a lifelong pattern of illness.

Stressful life events severity in patients with first and recurrent depressive episodes

BACKGROUND

Stressful life events are associated with depression and their role in first onset and recurrences is a promising but controversial perspective of research. The objective is to analyze the role of number of previous episodes and life events exposure in a large sample of primary care depressive patients taking into account life events severity.

METHOD

10,257 patients with DSM-IV criteria for a current single or recurrent major depressive episode were recruited by 2,056 general practitioners in a cross-sectional epidemiological study. Patients answered the Montgomery-Asberg Depression Rating Scale, the Patient Health Questionnaire and the Social Readjustment Rating Scale (SRRS). Stressful life events were categorized into three levels of severity (severe, moderate and mild). All relevant confounding variables were analyzed: age, gender, depression severity, somatic symptoms severity and length of episode.

RESULTS

We found a significant positive correlation with number of episodes and depression severity. There was no significant correlation of SRRS scores with age, gender and length of episode. ANOVA exploring life events severity with regard to number of episodes showed statistically differences in SRRS total score, moderate life events and mild life events (F = 15.14, p < 0.001) but not for severe life events.

CONCLUSIONS

Prevention and treatment strategies for recurrent depression need to manage life stressful events during mild and long-term periods and not just in the initial recurrences of the disease.

Social vs. environmental stress models of depression from a behavioural and neurochemical approach

Major depression is a mental disorder often preceded by exposure to chronic stress or stressful life events. Recently, animal models based on social conflict such as chronic social defeat stress (CSDS) are proposed to be more relevant to stress-induced human psychopathology compared to environmental models like the chronic mild stress (CMS). However, while CMS reproduces specifically core depressive symptoms such as anhedonia and helplessness, CSDS studies rely on the analysis of stress-induced social avoidance, addressing different neuropsychiatric disorders. Here, we study comparatively the two models from a behavioural and neurochemical approach and their possible relevance to human depression. Mice (C57BL/6) were exposed to CMS or CSDS for six weeks and ten days. Anhedonia was periodically evaluated. A battery of test applied during the fourth week after the stress procedure included motor activity, memory, anxiety, social interaction and helplessness. Subsequently, we examined glutamate, GABA, 5-HT and dopamine levels in the prefrontal cortex, hippocampus and brainstem. CMS induced a clear depressive-like profile including anhedonia, helplessness and memory impairment. CSDS induced anhedonia, hyperactivity, anxiety and social avoidance, signs also common to anxiety and posttraumatic stress disorders. While both models disrupted the excitatory inhibitory balance in the prefrontal cortex, CMS altered importantly this balance in the brainstem. Moreover, CSDS decreased dopamine in the prefrontal cortex and brainstem. We suggests that while depressive-like behaviours might be associated to altered aminoacid neurotransmission in cortical and brain stem areas, CSDS induced anxiety behaviours might be linked to specific alteration of dopaminergic pathways involved in rewarding processes.

Psychosocial stressors and the prognosis of major depression: a test of Axis IV

BACKGROUND

Axis IV is for reporting 'psychosocial and environmental problems that may affect the diagnosis, treatment and prognosis of mental disorders'. No studies have examined the prognostic value of Axis IV in DSM-IV.

METHOD

We analyzed data from 2497 participants in the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) with major depressive episode (MDE). We hypothesized that psychosocial stressors predict a poor prognosis of MDE. Secondarily, we hypothesized that psychosocial stressors predict a poor prognosis of anxiety and substance use disorders. Stressors were defined according to DSM-IV's taxonomy, and empirically using latent class analysis (LCA).

RESULTS

Primary support group problems, occupational problems and childhood adversity increased the risks of depressive episodes and suicidal ideation by 20-30%. Associations of the empirically derived classes of stressors with depression were larger in magnitude. Economic stressors conferred a 1.5-fold increase in risk for a depressive episode [95% confidence interval (CI) 1.2-1.9]; financial and interpersonal instability conferred a 1.3-fold increased risk of recurrent depression (95% CI 1.1-1.6). These two classes of stressors also predicted the recurrence of anxiety and substance use disorders. Stressors were not related to suicidal ideation independent from depression severity.

CONCLUSIONS

Psychosocial and environmental problems are associated with the prognosis of MDE and other Axis I disorders. Although DSM-IV's taxonomy of stressors stands to be improved, these results provide empirical support for the prognostic value of Axis IV. Future work is needed to determine the reliability of Axis IV assessments in clinical practice, and the usefulness of this information to improving the clinical course of mental disorders.

Cortisol responses to psychosocial stress predict depression trajectories: social-evaluative threat and prior depressive episodes as moderators

BACKGROUND

Alterations of hypothalamic-pituitary-adrenal (HPA) function are well-established in adults with current depression. HPA alterations may persist into remission and confer increased risk for recurrence.

METHODS

A modified version of the Trier Social Stress Test (TSST) was administered at baseline to 32 young adults with remitted major depressive disorder and 36 never-depressed controls. Participants were randomly assigned to either a 'high-stress' condition involving social evaluation or a 'low-stress' control condition. Cortisol concentrations were measured in saliva samples throughout the TSST. Participants were assessed again after 6 months for the occurrence of stressful life events and depressive symptoms/disorders during the follow-up period.

RESULTS

Participants who exhibited enhanced cortisol reactivity in the low-stress condition showed increases in depressive symptoms over follow-up, after controlling for stressful life events during the follow-up period. Anticipatory stress cortisol and cortisol reactivity each interacted with history of depressive episodes to predict depression trajectories.

LIMITATIONS

The single TSST administration limits conclusions about whether alterations of cortisol reactivity represent trait-like vulnerability factors or consequences ("scars') of past depression.

CONCLUSIONS

These results extend previous findings on stress sensitivity in depression and suggest that altered HPA function during remission could reflect an endophenotype for vulnerability to depression recurrence. Findings support interactive models of risk for depression recurrence implicating HPA function, depression history, and sensitivity to minor stressors. Results may have implications for interventions that match treatment approaches to profiles of HPA function.

Chronic social defeat stress model: behavioral features, antidepressant action, and interaction with biological risk factors

RATIONALE

Chronic social defeat stress (CSDS) has been proposed as a model of depression. However, most CSDS studies rely only on the analysis of stress-induced social avoidance. Moreover, the predictive validity of the model has been poorly analyzed, let alone its interaction with biological risk factors.

OBJECTIVES

Here, we explore the validity of CSDS as a depression model. Further, the effect of decreased vesicular glutamate transporter 1 (VGLUT1), as a potential factor enhancing a depressive-like phenotype, was studied.

METHODS

Mice were exposed to CSDS (10 days) followed by saline, venlafaxine, fluoxetine, or tianeptine treatment (30 days). The battery of behaviors included motor activity, memory, anxiety, social interaction, helplessness, and anhedonic-like behavior. Moreover, the behavioral effect of CSDS in VGLUT1 heterozygous (VGLUT1+/-) mice was studied, as well as the regulation of VGLUT1 mRNA.

RESULTS

CSDS induced anhedonia, helplessness, hyperactivity, anxiety, social avoidance, and freezing, as well as downregulation of VGLUT1 mRNA in the amygdala. Repeated venlafaxine showed antidepressant-like activity and both venlafaxine and tianeptine behaved as effective anxiolytics. CSDS-induced social avoidance was reverted by tianeptine. Fluoxetine failed to revert most of the behavioral alterations. VGLUT1+/- mice showed an enhanced vulnerability to stress-induced social avoidance.

CONCLUSION

We suggest that CSDS is not a pure model of depression. Indeed, it addresses relevant aspects of anxiety-related disorders. Firstly, CSDS-induced anhedonia and social avoidance are not associated in this model. Moreover, CSDS might be affecting brain areas mainly involved in the processing of social behavior, such as the amygdala, where the glutamatergic mechanism could play a key role.

Homeopathic Individualized Q-Potencies versus Fluoxetine for Moderate to Severe Depression: Double-Blind, Randomized Non-Inferiority Trial

Homeopathy is a complementary and integrative medicine used in depression, The aim of this study is to investigate the non-inferiority and tolerability of individualized homeopathic medicines [Quinquagintamillesmial (Q-potencies)] in acute depression, using fluoxetine as active control. Ninety-one outpatients with moderate to severe depression were assigned to receive an individualized homeopathic medicine or fluoxetine 20 mg day(-1) (up to 40 mg day(-1)) in a prospective, randomized, double-blind double-dummy 8-week, single-center trial. Primary efficacy measure was the analysis of the mean change in the Montgomery & Åsberg Depression Rating Scale (MADRS) depression scores, using a non-inferiority test with margin of 1.45. Secondary efficacy outcomes were response and remission rates. Tolerability was assessed with the side effect rating scale of the Scandinavian Society of Psychopharmacology. Mean MADRS scores differences were not significant at the 4th (P = .654) and 8th weeks (P = .965) of treatment. Non-inferiority of homeopathy was indicated because the upper limit of the confidence interval (CI) for mean difference in MADRS change was less than the non-inferiority margin: mean differences (homeopathy-fluoxetine) were -3.04 (95% CI -6.95, 0.86) and -2.4 (95% CI -6.05, 0.77) at 4th and 8th week, respectively. There were no significant differences between the percentages of response or remission rates in both groups. Tolerability: there were no significant differences between the side effects rates, although a higher percentage of patients treated with fluoxetine reported troublesome side effects and there was a trend toward greater treatment interruption for adverse effects in the fluoxetine group. This study illustrates the feasibility of randomized controlled double-blind trials of homeopathy in depression and indicates the non-inferiority of individualized homeopathic Q-potencies as compared to fluoxetine in acute treatment of outpatients with moderate to severe depression.

Stressful life events and social health factors in women using anxiolytics and antidepressants: an Italian observational study in community pharmacies

BACKGROUND

In Italy, as in all of Europe, women differ from men in that they are somewhat more sensitive to the depressogenic effects of stressful life events related to their social networks and emotional sphere. Women are more likely than men to have experienced poverty, gender discrimination, and physical and sexual abuse.

OBJECTIVE

The purpose of this study was to expand the knowledge about the occurrence of stressful life events in women exposed and not exposed to anxiolytics and antidepressants in a community pharmacy setting.

METHODS

Women attending 100 community pharmacies in the Italian Veneto region were surveyed by pharmacists with regard to a number of general features of their current pharmacologic treatment. Women independently completed a written self-assessment questionnaire that focused on stressful life events. Unconditional logistic regression analysis was performed to investigate the association between anxiolytics and antidepressants use and potential factors, including stressful life events.

RESULTS

The study population comprised 11,357 women. One or more stressful life events occurred in 90% of the women treated with anxiolytics and/or antidepressants (users [n = 3848]) and in 74% of the women not treated with these drugs (nonusers [n = 7509]) (odds ratio = 3.19; 95% CI, 2.83-3.60). On average, the life events occurred during the previous 6 months and the women considered the influence of these events on their well-being to be severe. After the unconditional logistic regression analysis, the association between anxiolytics and/or antidepressants use remained positive for most of the stressful life events studied as well as for other factors: separation/divorce, living alone or with others (family or friends), unemployment, whether currently being seen by a psychologist/psychiatrist, and treatment with drugs for the alimentary tract and metabolism, cardiovascular system, or nervous system.

CONCLUSIONS

A significant association between stressful life events and anxiolytics and/or antidepressants use was observed. Further efforts are needed to increase our knowledge of the use of anxiolytics or antidepressants in relation to the occurrence of life events.

Chronic stress and impaired glutamate function elicit a depressive-like phenotype and common changes in gene expression in the mouse frontal cortex

Major depression might originate from both environmental and genetic risk factors. The environmental chronic mild stress (CMS) model mimics some environmental factors contributing to human depression and induces anhedonia and helplessness. Mice heterozygous for the synaptic vesicle protein (SVP) vesicular glutamate transporter 1 (VGLUT1) have been proposed as a genetic model of deficient glutamate function linked to depressive-like behaviour. Here, we aimed to identify, in these two experimental models, gene expression changes in the frontal cortex, common to stress and impaired glutamate function. Both VGLUT1(+/-) and CMS mice showed helpless and anhedonic-like behavior. Microarray studies in VGLUT1(+/-) mice revealed regulation of genes involved in apoptosis, neurogenesis, synaptic transmission, protein metabolic process or learning and memory. In addition, RT-PCR studies confirmed gene expression changes in several glutamate, GABA, dopamine and serotonin neurotransmitter receptors. On the other hand, CMS affected the regulation of 147 transcripts, some of them involved in response to stress and oxidoreductase activity. Interestingly, 52 genes were similarly regulated in both models. Specifically, a dowregulation in genes that promote cell proliferation (Anapc7), cell growth (CsnK1g1), cell survival (Hdac3), and inhibition of apoptosis (Dido1) was observed. Genes linked to cytoskeleton (Hspg2, Invs), psychiatric disorders (Grin1, MapK12) or an antioxidant enzyme (Gpx2) were also downregulated. Moreover, genes that inhibit the MAPK pathways (Dusp14), stimulate oxidative metabolism (Eif4a2) and enhance glutamate transmission (Rab8b) were upregulated. We suggest that these genes could form part of the altered "molecular context" underlying depressive-like behaviour in animal models. The clinical relevance of these findings is discussed.

A prospective study of stress autonomy versus stress sensitization in adolescents at varied risk for depression

This longitudinal study investigated the stress autonomy, stress sensitization, and depression vulnerability hypotheses in adolescents across 6 years (i.e., Grades 6 through 12). Participants were 240 children (Time 1 mean age = 11.86, SD = 0.57) who varied in risk for depression on the basis of their mother's history of mood disorders. All analyses were conducted as multilevel models to account for nesting in the data. Results were consistent with the stress sensitization hypothesis. The within-subject relation of stress levels to depressive symptoms strengthened with increasing numbers of prior depressive episodes. In addition, evidence consistent with the vulnerability hypothesis was found. The relation of stress levels to depressive symptoms was stronger for adolescents who were at risk for depression on the basis of maternal depression history and for those who had experienced more depressive episodes through Grade 12. These findings suggest that onsets of depression in adolescents may be predicted by both relatively stable and dynamic transactions between stressful life events and vulnerabilities such as maternal depression and youths' own history of depressive episodes.

Understanding depressive rumination from a cognitive science perspective: the impaired disengagement hypothesis

Persisting negative thoughts are considered a hallmark of depression. Recent information-processing approaches have begun to uncover underlying mechanisms of depressive rumination. Despite marked advances in this area, there is a lack of integration between psychopathology and cognitive (neuro) science research. We propose the 'impaired disengagement' hypothesis as a unifying framework between both approaches. The core tenet of our model is that prolonged processing of self-referent material is due to impaired attentional disengagement from negative self-referent information. We discuss empirical evidence for this framework and outline future ways in which the causal predictions of this model can be tested. The proposed framework can account for effectiveness of various treatments for depression and may aid in devising new interventions to target depressive cognition.

[Severe depression: recurrence and chronicity]

This review paper deals with the question of the relationships between clinical severity of depression, recurrence risk and chronicity risk. About 60% of the subjects with a first episode of major depression will present a second episode lifetime. The risk of recurrence increases slightly with the severity of the index episode. Conversely, depression severity tends to be slightly higher in recurrent episodes as compared with first episodes. This is supported by a few studies of consecutive episodes within the same patients but it could also result from a selection effect. The risk that a depressive episode is still meeting the criteria of a major depressive episode two years after onset is between 10 and 20%. Neither the severity of the index episode nor its recurrent character clearly increases the risk of its chronic evolution. Finally, minor depression (as a dysthymic disorder or residual symptoms) increases the risk of a new major depressive episode. We may conclude that there are only moderate interactions between the clinical severity of depression and the risks of chronicity and recurrence. Worsening of one of these three variables will not result into a dramatic worsening of the two others. In fact, chronicity and recurrence do not specifically contribute to the severity of the next episode, they only contribute to the long-term severity of depressive disorders, which is already by itself a major issue.

Stressful life events and depressive symptoms: influences of gender, event severity, and depression history

Informed by Post's (1992) kindling hypothesis, the study examined the association between depressive symptoms and varying levels of perceived life events as determined by respondents, as well as the moderating role of depression history and gender. Severe life events were significantly associated with current depressive symptoms among never depressed women but not among women with depression history. Such a moderating role of depression history was not observed among men where severe life events were associated with current depressive symptoms in men regardless of depression history. No moderating effects of gender and depression history were obtained for mild and moderate life events, but these events were significantly associated with current depressive symptoms. These results support Post's kindling hypothesis for severe life events but not for mild or moderate life events, and further only in women.

The cumulative impact of nonsevere life events predicts depression recurrence during maintenance treatment with interpersonal psychotherapy

Although much research has focused on the role of severe life events as risk factors for depression onset, less is known about the relationship between nonsevere life events and depression recurrence. The current study examined the cumulative effects of nonsevere and positive life events on depression recurrence in an outpatient sample of recurrently depressed women treated to remission with interpersonal psychotherapy (IPT). A Cox proportional hazards model was used to test this relationship in 124 adult women who entered into the maintenance phase of IPT treatment and completed at least 1 Life Events and Difficulties Schedule interview. The cumulative experience of nonsevere life events that were subject- or joint-focused and nonindependent was significantly related to depression recurrence during the maintenance treatment phase. None of the other event categories were significantly related to depression recurrence. These findings may help to clarify the mechanisms by which life events contribute to depression recurrence and to guide the development of more efficacious maintenance treatments.

Transient forebrain over-expression of CRF induces plasma corticosterone and mild behavioural changes in adult conditional CRF transgenic mice

BACKGROUND

Converging findings support a role for extra-hypothalamic CRF in the mediation of the stress response. The influence of CRF in the amygdala is well established, while less is known of its role in other areas of the forebrain where CRF and CRF(1) receptors are also expressed. In the present study CRF was genetically induced to allow forebrain-restricted expression in a temporally-defined manner at any time during the mouse lifespan. This mouse model may offer the possibility to establish a model of the pathogenesis of recurrent episodes of depression.

METHODS

Mice were engineered to carry both the rtTA transcription factor driven by the CamKII alpha promoter and the doxycycline-regulated operator (tetO) upstream of the CRF coding sequence. Molecular, biochemical and behavioural characterisation of this mouse is described.

RESULTS

Following a three-week period of transcriptional induction, double transgenic mice showed approximately 2-fold increased expression of CRF mRNA in the hippocampus and cortex, but not hypothalamus. These changes were associated with 2-fold increase in morning corticosterone levels, although responses to the dexamethasone suppression test or acute stress were unaffected. In contrast, induced mice displayed modestly altered behaviour in the Light and Dark test and Forced Swim test.

CONCLUSIONS

Transient induction of CRF expression in mouse forebrain was associated with endocrine and mild anxiety-like behavioural changes consistent with enhanced central CRF neurotransmission. This mouse allows the implementation of regimens with longer or repeated periods of induction which may model the initial stages of the pathology underlying recurrent depressive disorders.

Long-lasting behavioral effects and recognition memory deficit induced by chronic mild stress in mice: effect of antidepressant treatment

RATIONALE

Many studies support the validity of the chronic mild stress (CMS) model of depression in rodents. However, most of them focus on analysis of reactivity to rewards during the CMS and/or depressive-like behavior shortly after stress. In this study, we investigate acute and long-term effects of CMS and antidepressant treatment on depressive, anxiety-like behavior and learning.

MATERIALS AND METHODS

Mice (C57BL/6) were exposed to CMS for 6 weeks and anhedonia was evaluated by weekly monitoring of sucrose intake. Paroxetine (10 mg kg(-1)day(-1) i.p.) or saline were administered the last 3 weeks of CMS and continued for 2 weeks thereafter. Behavioral tests were performed over the last week of CMS (acute effects) and 1 month later (long-term effects).

RESULTS

Mice exposed to CMS displayed both acute and long-term decreased sucrose intake, increased immobility in the forced swimming test (FST) and impaired memory in the novel object recognition test. It is interesting to note that a correlation was found between the cognitive deficits and the helpless behavior in the FST induced by CMS. During the CMS procedure, paroxetine treatment reverted partially recognition memory impairment but failed to prevent the increased immobility in the FST. Moreover, it decreased on its own sucrose intake. Importantly, the long-term effects of CMS were partially prevented by chronic paroxetine.

CONCLUSIONS

CMS leads to a long-term altered behavioral profile that could be partially reverted by chronic antidepressant treatment. This study brings novel features regarding the long-term effects of CMS and on the predictive validity of this depression animal model.

Prevention of depression: the state of the science at the beginning of the 21st Century

Major depression is one of the most prevalent mental disorders and the number one cause of disability worldwide. Once a person experiences a major depressive episode (MDE), the likelihood of recurrence is very high. The prevention of first onset, as well as the protection against recurrence after recovery, are therefore essential goals for the mental health field. By the end of the 20th century, however, most depression research efforts had focused on either acute or prophylactic treatment. In this article, we review USA and international studies that have attempted to reduce incidence of MDE, either 1) to prevent onset in populations of children and adults (including women during the postpartum period) not currently meeting diagnostic criteria for depression, or 2) to prevent a new episode in individuals who have recovered after treatment through protective, but not prophylactic interventions. We identified twelve randomized controlled trials focused on preventing the onset of major depression (both MDE and postpartum depression (PPD)), five randomized controlled trials focusing on preventing relapse, and no randomized controlled trials focused exclusively on preventing recurrent episodes through protective interventions. The review is limited in scope given that depression prevention trials focused on infants, young children, and older adults were not included in the review. The research to date suggests that the prevention of major depression is a feasible goal for the 21st century. If depression prevention interventions become a standard part of mental health services, unnecessary suffering due to depression will be greatly reduced. This review concludes with suggestions for the future direction of depression prevention research.

Psychiatric epidemiology: challenges and opportunities

This paper discusses challenges and prospects for increasing the clinical relevance of psychiatric epidemiological research. The discussion begins with a review of the structural determinants of the fact that current psychiatric epidemiological research has less clinical relevance than epidemiological research in other areas of medicine. The discussion then turns to ways in which the focus of psychiatric epidemiological research might be changed to increase its clinical relevance. A review is then presented of recent innovations in community psychiatric epidemiological research that were designed to increase clinical relevance. An argument is then made that the full clinical value of psychiatric epidemiology will only be realized when community epidemiology becomes better integrated with clinical epidemiology and the latter takes on a more prominent role than it currently has in psychiatric research. Existing initiatives to realize an integration of community psychiatric epidemiology with clinical epidemiology are then reviewed. Finally, an agenda is proposed for an expansion of clinical psychiatric epidemiology to include a focus on both naturalistic and quasi-experimental studies of illness course and treatment response in diverse clinical samples.

Severe life events predict specific patterns of change in cognitive biases in major depression

BACKGROUND

A long-standing debate concerns whether dysfunctional cognitive processes and content play a causal role in the etiology of depression or more simply represent correlates of the disorder. There has been insufficient appreciation in this debate of specific predictions afforded by cognitive theory in relation to major life stress and changes in cognition over time. In this paper we present a novel perspective for investigating the etiological relevance of cognitive factors in depression. We hypothesize that individuals who experienced a severe life event prior to the onset of major depression will exhibit greater changes in dysfunctional attitudes over the course of the episode than will individuals without a severe life event.

METHOD

Fifty-three participants diagnosed with major depression were assessed longitudinally, approximately 1 year apart, with state-of-the-art measures of life stress and dysfunctional attitudes.

RESULTS

Depressed individuals with a severe life event prior to episode onset exhibited greater changes in cognitive biases over time than did depressed individuals without a prior severe event. These results were especially pronounced for individuals who no longer met diagnostic criteria for major depression at the second assessment.

CONCLUSIONS

Specific patterns of change in cognitive biases over the course of depression as a function of major life stress support the etiological relevance of cognition in major depression.