“I believe there is a reason such as autism, severe manic-depression, and schizophrenia remain in our gene pool even though there is much suffering as a result.”

“What would happen if the autism gene was eliminated from the gene pool?You would have a bunch of people standing around in a cave, chatting and socializing and not getting anything done.”

“You're manic-depressive and you're manic-depressive too and you, you're definitely manic-depressive, girl. And you over there in the corner, you're just plain fucking depressive.”

“Even a manically depressed robot is better to talk to than nobody.”

“But money spent while manic doesn't fit into the Internal Revenue Service concept of medical expense or business loss. So after mania, when most depressed, you're given excellent reason to be even more so.”

“Nesse’s research focuses on the evolutionary origins of depression. Why does depression exist at all? If it’s stayed in our gene pool for so long, he argues, there must be some evolutionary benefit. Nesse believes that depression may be an adaptive mechanism meant to prevent us from falling victim to blind optimism—and squandering resources on the wrong goals.11 It’s to our evolutionary advantage not to waste time and energy on goals we can’t realistically achieve. And so when we have no clear way to make productive progress, our neurological systems default to a state of low energy...”