Common Mental Disorders Depression - New Zealand Doctor

1.4 Etiology of common mental disorders
The etiology of common mental disorders is multifactorial and complex. It involves
the interaction of differing susceptibilities, environmental exposures and stressful life
events, 65,66 and encompasses a range of genetic, 67 developmental, 68 biochemical, 69
endocrine, 70 nutritional 71 and psychosocial 72 factors. Moreover most risk factors,
whether genetic or environmental, involve probabilistic rather than deterministic
effects. 67 This complexity explains the heterogeneity of presentations and may account
for differential responses to treatment. There is strong research interest in genetic 53,67
and biochemical vulnerabilities 73-76 and their influence on mental health, including the
potential for biochemical prevention and/or treatment of depression. 77,78
There is widespread acceptance that mental disorders can be triggered by the
interaction of individual risk factors with stressful situations. 66,79 However, this sequence
of events does not invariably apply; further, there are factors that appear to protect
against depression following a stressful life event. 65 For a first episode of depression,
the commonly encountered risk factors are detailed in Table 1.3, along with a short list
of protective/resilience factors.
Table 1.3
Risk factors and resilience factors for depression
Common risk factors
(which could lead to vulnerability)
Resilience factors
(protective in the presence of risk factors)
Parental history of depression Good parenting §
Difficult temperament as a child* Easy temperament as a child †
Attachment difficulties/parental neglect
Family discord ‡
Previous depression/anxiety in adulthood
Ruminating over negative circumstances
Good peer relationships
Stability in love relationships
Has coped with past difficulties well
* Displays behaviour such as impulsiveness, shyness, difficulty in concentrating, easily upset,
poor task persistence, irritability.
†
Displays behaviour such as adaptability in novel situations, sociability; has a low intensity of
reactions.
‡
Tension between parental figures, arguments or fighting (often preceded by financial problems).
§
Research indicates that good parenting includes emotional warmth and cognitive stimulation
(Kim-Cohen 2004). 82
Sources:
Bruder-Costello B, et al. Psychiatry Res 2007;153(2):145–51. 80
Brown GW, et al. J Affect Disord 2007;103;(1-3):225–3. 81
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Identification of Common Mental Disorders and Management of Depression in Primary Care