Targeting depressive symptoms is unlikely to helpBMJ 2010; 341 doi: http://dx.doi.org/10.1136/bmj.c4697 (Published 07 September 2010) Cite this as: BMJ 2010;341:c4697
- James C Coyne, professor of psychology in psychiatry1
Ritchie and colleagues urge moving from observational epidemiology to public health interventions to reduce dementia and propose reducing depressive symptoms.1 This is a poor example except as an opportunity to reflect on the pitfalls of inferring modifiable risk from correlation.
Depressive symptoms are related to a host of antecedent and cross sectional correlates ranging from economic to psychological variables. They similarly correlate with physical health, physical role functioning, all cause mortality, and mortality associated with specific health conditions. Isolating an association between depressive symptoms and a specific health outcome risks making too much of a spurious association or positing a specific mechanism when others are just as plausible and more testable.
Most increases in depressive symptoms do not represent depressive disorders for which evidence based treatments exist. Moreover, most treatment for depression in the community is inadequate or inappropriate.2 Non-syndromal depressive symptoms are not appropriate targets for treatment with antidepressants, though initiating treatment in people with symptoms but who do not have major depression probably contributed to a twofold to fourfold increase in antidepressant use.3
The ENRICH-D4 trial was a multimillion dollar trial with negative results of enhanced care for depressive disorders among patients with recent myocardial infarction with the aim of preventing re-infarction and reducing mortality.4 A systematic review and meta-analysis concluded that, despite an association between depression and cardiovascular outcomes, routine screening for depression in patients with heart disease was not warranted.5 Perhaps we should consider the folly of jumping from correlation to large scale interventions not only for depressive symptoms and cardiovascular outcomes but also for depressive symptoms and dementia.
Cite this as: BMJ 2010;341:c4697
Competing interests: None declared.