It is practically an article of faith among psychotherapists that an intimate human relationship is good for you. None other than Freud himself once famously said that health requires success in work and in love.

I’m not so sure. It seems that for some people, love and intimacy might not just be undesirable but downright toxic.

Not long ago, a man consulted me about his 35-year-old son, who had made a suicide attempt.

“I was shocked, because he never seemed depressed or unhappy in his life,” the man said of his son. “He always preferred his own company, so we were relieved when he started to date.”

He went on to tell me that he and his wife had strongly encouraged their son to become engaged to a woman he was dating. “She was perfect for him,” he recalled. “Warm, intelligent and affectionate.”