I guess you'd have to sustain the argument for group selection in general first. On the individual level, it wouldn't surprise me if the more 'seasonal' variati

I guess you'd have to sustain the argument for group selection in general first. On the individual level, it wouldn't surprise me if the more 'seasonal' variations of depression are an evolved resource conservation strategy (now maladaptive), in a season (winter) when 'pickings are slim'. I always have to remind myself that evolution doesn't optimise for happiness.