THE WASHINGTON TIMES The language of Valentine's Day cards and love songs — "crazy for you," "madly in love," et cetera — may reveal an important truth. Sometimes, love looks like a mental disorder, says British clinical psychologist Frank Tallis. "Love seems to have the power to destabilize people emotionally," says Mr. Tallis, who has lectured in psychology and neuroscience at the Institute of Psychiatry at King's College in London. "Particularly in vulnerable individuals, it can be very difficult to cope." The author of "Love Sick: Love as a Mental Illness," Mr. Tallis has a private practice in London, where...