DNA is not the heart’s destiny; the genetic lottery may determine the cards in your deck, but experience deals the hand you can play. - Thomas Lewis

When people have trouble with their emotions – a bout of anxiety or depression, say, or seasonal gloominess - they often want science to pinpoint an offending neurotransmitter in the way that a witness picks the perp out of a lineup. Is it excessive norepinephrine, too little dopamine, errant estrogen? The answer is apt to dissatisfy: no single suspect can be fingered with confidence because the question itself attributes a fallacious simplicity to the brain.

When somebody loses his partner and says a part of him is gone, he is more right than he thinks. A portion of his neural activity depends on the presence of that other living brain. Without it, the electric interplay that makes up him has changed.

Will lectures on the evils of chemical dependency deter teenagers from a life of substance dependence? Don’t believe it. While their end is worthy, such talk targets the neocortical brain, not the limbic one. Pain is too potent a motivator for facts to undo. Pretending otherwise is a threadbare illusion convincing only to those who already feel basically well.