REVIEW OF: Wu Q et al, J Affect Disord 2022;307:37–45

STUDY TYPE: Meta-analysis of placebo-controlled trials 

It’s difficult to evaluate risk factors for something as complex as depression. This umbrella review combed through systematic reviews and meta-analyses to identify risk and protective factors for depression in adults 60 years and older and to evaluate the quality of the evidence. Ideally, if we could identify modifiable risk factors early on, we could intervene to reduce an individual’s depression risk. 

The authors included 22 meta-analyses and three systematic reviews to look at 82 associations (risk and protective factors) in a total of 1,199,927 participants. They evaluated 48 associations quantitatively, with more than 60% indicating nominal statistical significance. Two factors, “high-dose” (500 mg) daily aspirin and age greater than 80 years, had the strongest evidence as risk factors for depression. Four additional risk factors were highly suggestive: sleep disturbances, hearing problems, vision problems, and cardiac disease. In terms of protective factors, the authors found an association between a healthy diet (odds ratio [OR] 0.85), omega-3 fatty acid intake (OR 0.74), and physical activity (OR 0.81).

There were a number of limitations with this study. Unfortunately, low-quality and even critically low-quality studies were included. Also, the authors did not evaluate studies focusing on subtypes of depression (eg, poststroke, dysthymia). 

Carlat Take

The evidence for risk factors for depression in older adults is surprisingly poor when subject to strict analysis. Keep a close eye on patients with a high medical burden and visual or hearing impairments. Encourage patients to eat well and keep moving. Unlike low-dose aspirin (75–150 mg), which is primarily used for the prevention of cardiovascular and thromboembolic events, high-dose aspirin is primarily used for pain relief and may be a marker for medical morbidity in these studies. Reassuringly, low-dose aspirin does not seem to increase ­depression.