Peter Kramer's book, "Listening to Prozac" first drew society's attention to the potential of psychopharmacology for enhancing the lives of healthy people. Several of his patients who had stopped taking Prozac asked to go back on. It was not because they were slipping back into depression. They were free of depression; in common parlance they were well. But on the drug they had been "better than well."

Little is known about the effects of SSRIs on normal people. Although they are not happy pills, shifting depressed people to normalcy and normal people to bliss, they do seem to attenuate negative emotion —for example, reducing the subjectively experienced "hassle" factor of life. They also seem to have a subtle but positive influence on the quality of people's social interactions.

Vegetative functions such as sleep, eating, and sexuality are often disrupted by mood disorders and, like mood, are aspects of life that the healthy may wish to enhance pharmacologically. For example, the wakefulness-promoting agent modafinil, approved in the US for treatment of certain sleep disorders, is prescribed off label for a panoply of other conditions and is said to be favored by some ambitious professionals as a way of packing more work into a day. It may also have a subtle enhancing effect on cognition. Although a safe and effective appetite suppressant is at present just a goal, such a drug will undoubtedly find a huge market when it comes along. Even after it became clear that the Phen-Fen combination could be fatal and it was pulled from the market, there was a constituency of consumers that fought for continued access to it. Finally, although currently popular medications for erectile dysfunction do not achieve their effects by altering brain function, newer neurally active drugs are in development, aimed at improving both male and female libido. If society's experience with sildenafil (Viagra) is any indication, many people without sexual dysfunction will seek these drugs to enhance their sex lives.

As with cognitive enhancement, enhancement of affective and vegetative functions raises three types of ethical issues. Safety, particularly with long-term use of drugs by healthy people, is a concern. The likely social effects of enhancing affective and vegetative functions are also similar to those mentioned in connection with cognitive enhancement. For example, the ability to dispense with sleep for long periods would undoubtedly give some workers a competitive edge, whereas other workers might find themselves pressured to enhance mood by a boss who prefers a cheery workplace. Treatments or enhancements that influence mood or motivation could also conceivably be used for social control.

Mood enhancement also raises philosophical issues. As with enhancement of cognition, some are bothered by the effortlessness of lifting mood with a pill, rather than earning one's happiness. Perhaps even more than with cognitive enhancement, mood enhancement raises questions about personal identity and authenticity. If we fall in love with someone who is on Prozac and then find she is difficult and temperamental off the drug, do we conclude we don't love her after all? Then who was it we loved?

Martha J. Farah