I'm a big fan of evolutionary medicine and Randy Nesse in particular. I think looking at medical situations from an evolutionary perspective is enlightening, sometimes revolutionary, and this approach can be extended into psychiatry. I think many times medicine and psychiatry have labeled some things as malfunctions when they're actually nature's solution to a deeper, hidden problem the brain or body is silently struggling to resolve. For example, fever, vomiting, diarrhea, sneezing, coughing, pain, fatigue, fear, guilt, shame, anger, are all things that evolved to protect us from some sort of harm. Nothing in medicine makes sense except in the light of evolution.