Depression: an inability to adapt to one's perceived life distress?

The relationship between the perception of major life events and depression: A systematic scoping review and meta-analysis

BACKGROUND

Major life events can lead to depression in adulthood. However, as predicted by several depression theories, not only the mere occurrence of major life events but also the way people perceive them determines the onset of a depression.

METHODS

Based on a systematic literature search, we identified 276 studies (Ntotal = 89,600) that examined the relationship between the perception of major life events and depression. We provide an overview of how this relationship has been examined. Furthermore, we meta-analytically integrated 420 effect sizes (172 studies) on the association between the perception of major life events and depression.

RESULTS

Most studies relied on college student samples, were cross-sectional, and were conducted in the United States. A more negative perception of events was significantly associated with higher levels of depressive symptoms (r = 0.28). This association was robust across several design and sample characteristics. Furthermore, the perception of major life events and depression were also longitudinally associated with each other (event perception predicting later depressive symptoms: r = 0.26; depressive symptoms predicting later event perception: r = 0.17).

LIMITATIONS

Longitudinal research on the relationship between depression and the perception of major life events was relatively rare impairing definite conclusions on whether the perception of life events can predict changes in depressive symptoms over time.

CONCLUSION

The perception of major life events is related to depression. However, further longitudinal research considering a range of different perceived event characteristics and using non-Western heterogeneous samples is needed to better understand their relationship.

Enhanced smoking cue salience associated with depression severity in nicotine-dependent individuals: a preliminary fMRI study

The association between cigarette smoking and depression has been well documented; however, little research has been done to elucidate the neurobiological substrates of this highly prevalent comorbidity. We used multiple linear regression analysis to evaluate the relationship between depression severity as assessed by the Hamilton Depression Rating Scale (HAMD) and blood oxygen level-dependent (BOLD) responses to visual smoking cues in drug-free nicotine-dependent smokers (n=18). Two functional magnetic resonance imaging (fMRI) scans were completed over a single study day, following overnight smoking abstinence (pre-smoking scan) and after cigarette reinstatement (post-smoking scan). During the pre-smoking scan positive correlations between BOLD activity and HAMD scores were observed in areas of the mesocorticolimbic dopaminergic system [inferior frontal gyrus, middle frontal gyrus (MFG), hippocampus (HC), anterior cingulate gyrus] and areas of the visuospatial attention circuit (medial occipital lobe, middle cingulate cortex, superior frontal gyrus, angular gyrus). During the post-smoking scan positive correlations were observed in areas of the brain implicated in drug expectancy (MFG), memory (HC), attentional motivation (posterior cingulate cortex), and visual processing and attention (precuneus). These preliminary findings demonstrate that smokers with higher depression severity attribute greater incentive salience to smoking-related cues and this is especially pronounced during periods of acute abstinence. Such enhanced salience of smoking cues, even after smoking a cigarette, may play a critical role both in the maintenance of smoking in depression and in greater levels of nicotine dependence seen in this patient population.

The neurobiology of depression and antidepressant action

We present a comprehensive overview of the neurobiology of unipolar major depression and antidepressant drug action, integrating data from affective neuroscience, neuro- and psychopharmacology, neuroendocrinology, neuroanatomy, and molecular biology. We suggest that the problem of depression comprises three sub-problems: first episodes in people with low vulnerability ('simple' depressions), which are strongly stress-dependent; an increase in vulnerability and autonomy from stress that develops over episodes of depression (kindling); and factors that confer vulnerability to a first episode (a depressive diathesis). We describe key processes in the onset of a 'simple' depression and show that kindling and depressive diatheses reproduce many of the neurobiological features of depression. We also review the neurobiological mechanisms of antidepressant drug action, and show that resistance to antidepressant treatment is associated with genetic and other factors that are largely similar to those implicated in vulnerability to depression. We discuss the implications of these conclusions for the understanding and treatment of depression, and make some strategic recommendations for future research.

Physical activity in the process of psychiatric rehabilitation: theoretical and methodological issues

Physical activity can potentially perform a valuable role within the context of psychiatric rehabilitation in terms of physical and mental health benefits. Theoretical and applied considerations have driven the search for the causal mechanism(s) that underpin mental health change through physical activity. To date, no single mechanism has been found to consistently explain changes. A key reason for this is that the occurrence of, and recovery from, mental health problems is influenced by many diverse factors. Both theoretical and methodological issues affect our ability to identify and understand these factors and, subsequently, our ability to promote psychiatric rehabilitation through physical activity. Alternative theoretical and methodological approaches are discussed here with the aim of encouraging a broad-based research agenda which will most effectively serve the needs of mental health service users. These approaches differ widely in scope but all share one thing in common: a personalized understanding of the process of mental health change in psychiatric rehabilitation.

Exposure of mice to a predator odor increases acoustic startle but does not disrupt the rewarding properties of VTA intracranial self-stimulation

The present investigation assessed the propensity of an acute psychogenic stressor exposure to induce behavioral change in paradigms assessing fear/anxiety (acoustic startle) and motivation/anhedonia (intracranial self-stimulation) in CD-1 mice. In the acoustic startle paradigm, a 10-min exposure of 2-4 month old mice (young adult mice) to fox odor (2,5-dihydro-2,4,5-trimethylthiazoline; TMT) was associated with decreased acoustic startle relative to mice exposed to the control odor, butyric acid (BA), immediately and relative to both saline and BA exposure 24 h following odor exposure in the home cage. In contrast, a 2-min exposure of young adult mice to TMT was associated with an increase in startle relative to saline and BA during the immediate post-odor test session only. In young adult mice a 2-min and a 10-min exposure to BA resulted in a startle profile of mice reminiscent of saline-treated mice. In comparison to young adult mice, a 2-min exposure of mature adult mice (5-7 months old) to TMT enhanced startle for up to 48 h relative to both saline and BA, while a 10-min exposure of mature adult mice to TMT enhanced startle for 168 h post-odor exposure relative to saline-exposed mice only. However, the greatest increase in startle amplitude (i.e. 48 h) was acquired following the 2-min exposure of mature mice to TMT. Among mature adult mice, a 10-min exposure to BA in the home cage eventuated in enhanced startle relative to saline-exposed animals 168 h following odor exposure. In comparison, exposure of mice to 10 min of TMT depressed responding for VTA brain stimulation at the initial 80 Hz frequency, but was ineffective in elevating reward thresholds relative to mice merely exposed to saline. Mice assessed in the ICSS paradigm were approximately 2-4 months old at the time of surgery and 5-7 months old at the completion of testing. These data suggest that acute odor exposure may induce a fear gradient dependent upon the perceived stressor severity and that the resultant anxiety-like effects are dependent on the duration of odor exposure, age of the animals and the temporal interval between odor presentation and behavioral testing. Moreover, the anxiogenic properties of psychogenic stressors can be separated from their anhedonic effects. The implications of these data for clinical psychopathology are discussed.

Distinct biopsychosocial profiles emerge among nonpatients

OBJECTIVES

The cross-sectional study comprised 30- to 55-year-old permanent employees (N=1784) of the Finnish Broadcasting Company (YLE).

METHODS

The participants (N=1339, response rate 75%) completed standardised questionnaires covering demographic items, physical health, work performance, stress symptoms, pain and musculoskeletal symptoms, and overall biopsychosocial health.

RESULTS

Physical symptoms (present often or continually) were reported by 15%, psychosomatic by 19% and psychosocial by 14%. The intercorrelations between 73 biopsychosocial variables revealed nine factors explaining 54.5% of variance for intrapersonal profiles and four factors explaining 59.2% of variance for interpersonal profiles. The Cronbach alphas for reliability ranged from.76 to.83. Three distinct biopsychosocial cluster profiles were found: Cluster 1 (n=290, 27%) loaded positively with the somatic and psychosocial variables, Cluster 2 (n=558, 51%) loaded negatively with the various biopsychosocial symptoms, and Cluster 3 (n=235, 22%) loaded positively with anxiety.

CONCLUSION

Discriminant function analysis confirmed that this cluster solution correctly classified 95.2% of the subjects in a nonpatient multiprofessional population, which supports the biopsychosocial approach also in work life issues.

The moderating effects of coping strategies on major depression in the general population

OBJECTIVES

To evaluate the moderating effects of various coping strategies on the association between stressors and the prevalence of major depression in the general population.

METHODS

Subjects from the Alberta buy-in component of the 1994-1995 National Population Health Survey (NPHS) were included in the analysis (n = 1039). Each subject was asked 8 questions about coping strategies that dealt with unexpected stress from family problems and personal crises. Major depression was measured using the World Health Organization's (WHO) Composite International Diagnostic Interview-Short Form (CIDI-SF) for major depression. The impacts of coping strategies in relation to psychological stressors on the prevalence of major depression were determined by examining interactions between coping and life stress on major depression using logistic regression modelling.

RESULTS

No robust impact of coping strategies in relation to various categories of stress evaluated in the NPHS was observed. There was evidence that the use of "pray and seek religious help" and "talks to others about the situations" as coping strategies by women moderated the risk of major depression in the presence of financial stress and relationship stress (with a partner). Using emotional expression as a coping strategy by women might decrease the risk of major depression in the presence of 1 or more recent life events, personal stress, relationship stress (with a partner), and environmental stress.

CONCLUSION

Different coping strategies may have a differential impact on the prevalence of major depression in specific circumstances. These findings may be important both to prevent and to treat depressive disorders.

The relevance of hierarchies, territories, defeat for depression in humans: hypotheses and clinical predictions

BACKGROUND

Hierarchical and territorial behaviour are widespread in animals and humans. The consequences of defeat have been linked to depression in humans. However, hierarchical and territorial behaviours are not mentioned in ICD10 or DSM1V. I therefore investigated the coverage in relevant textbooks.

METHOD

I searched the indices of books on Animal Behaviour, General Psychology and General Psychiatry for entries on Hierarchy, Territory and Dominance.

RESULTS

A paradox is revealed. Hierarchical and territorial behaviour are widespread in both animals and humans but are neglected in textbooks of human behaviour and mental problems. Four hypotheses are put forward to explain this paradox and explore its implications. 1. That hierarchical and territorial behaviours evolved before human consciousness. They are available to consciousness but not in the forefront of awareness. 2. That human hierarchical and territorial behaviour are overlaid by a cultural veneer of manners, which conceal the true state of affairs. 3. That humans have internal, mental, hierarchical aims in addition to external physical hierarchical aims. 4. That failure to achieve internal hierarchical aims may produce diminution of well being and changes in behaviour by the same biological mechanisms that are active in external hierarchical defeat. Three testable predictions follow from these hypotheses. 1. That there are common genetic factors and similar patterns of brain activity in homologous structures during hierarchical and territorial behaviour in man, primates and lower vertebrates. 2. That brain structures involved in external hierarchical conflict, consciousness and imagery will be active during internal hierarchical conflict. 3. Defeat of internal hierarchical aims produce depressed mood and satisfying alternative hierarchical aims are protective. Case examples are given to illustrate the existence of, and the consequences of defeat on, internal hierarchies.

LIMITATIONS

These hypotheses and predictions are theoretical and require confirmation or refutation by neuroimaging and prospective studies.

CONCLUSIONS

A neglect of human hierarchical behaviour by clinicians is suggested and discussed. The concept of internal hierarchies, if confirmed, may throw light on human striving, the emotions of defeat and the therapy of depression.