The statistical power to detect cG×E effects is another important consideration. Unless cG×E effects are many times larger than typical genetic main effects, most cG×E studies conducted to date have been underpowered. This has several implications. The most obvious is that true G×E effects may often go undetected. However, low power also increases the rate of false discoveries across a field. Given the potentially low prior probability of true cG×E hypotheses, stemming from the difficulty of identifying the correct genetic and environmental variables, the false discovery rate in cG×E research in psychiatry could be very high; the possibility that most or even all positive cG×E findings in psychiatry discovered to date represent type I errors cannot be discounted.
