Tijdschrift voor Psychiatrie 50 (2008) 8, 519 - 528
Subclinical depression: a clinically relevant condition?
background Subclinical depression is a condition in which a person has depressive symptoms but does not meet the criteria for a depressive disorder.
aim To give insight in the clinical relevance of subclinical depression. method A review of a series of studies that the authors co-authored on the subject of subclinical depression.
results These studies showed that subthreshold depression has serious consequences for the quality of life, but not as serious as in the case of a depressive disorder. It was also found that subthreshold (minor) depression can have considerable economic consequences for the individual concerned, although again less severe than if the individual had a depressive disorder. Because minor depression was more prevalent, the total costs of minor depression in the Netherlands (€ 1.5 billion per year) appeared to be comparable to those of major depression (€ 1.8 billion). It was also clear that subjects with subthreshold depression have an increased risk of developing a major depression. The degree of risk depended on a number of factors, including the definition of subthreshold depression. meta-analysis of seven studies examining the effects of psychological treatments of subthreshold depression showed that these treatments are effective (Cohen's d = 0.42; 95% ci: 0.23-0.60) and that they may well prevent the onset of major depression (incidence rate ratio: 0.70; 95% ci: 0.47-1.03; p < 0.1).
conclusion Subthreshold depression has serious consequences for the quality of life, but not as serious as in the case of a depressive disorder. Psychological treatment is effective.