Evolution theory: an overview of its applications in psychiatry

Were there evolutionary advantages to premenstrual syndrome?

Premenstrual syndrome (PMS) affects up to 80% of women, often leading to significant personal, social and economic costs. When apparently maladaptive states are widespread, they sometimes confer a hidden advantage, or did so in our evolutionary past. We suggest that PMS had a selective advantage because it increased the chance that infertile pair bonds would dissolve, thus improving the reproductive outcomes of women in such partnerships. We confirm predictions arising from the hypothesis: PMS has high heritability; gene variants associated with PMS can be identified; animosity exhibited during PMS is preferentially directed at current partners; and behaviours exhibited during PMS may increase the chance of finding a new partner. Under this view, the prevalence of PMS might result from genes and behaviours that are adaptive in some societies, but are potentially less appropriate in modern cultures. Understanding this evolutionary mismatch might help depathologize PMS, and suggests solutions, including the choice to use cycle-stopping contraception.

Evolutionary psychiatry and depression: testing two hypotheses

In the last few decades, there has been a genuine 'adaptive turn' in psychiatry, resulting in evolutionary accounts for an increasing number of psychopathologies. In this paper, I explore the advantages and problems with the two main evolutionary approaches to depression, namely the mismatch and persistence accounts. I will argue that while both evolutionary theories of depression might provide some helpful perspectives, the accounts also harbor significant flaws that might question their authority and usefulness as explanations.