From the cutting edge of neurophysiology and neuropharmacology, science writer Stephen Braun (author of Buzz: The Science and Lore of Alcohol and Caffeine) brings us an accessible examination of science's attempts to give us a positive outlook on life, a sense of well-being and satisfaction. "Our desire for happiness is profoundly powerful. It is composed of braided desires, hopes, and dreams that, themselves, can be overpowering. Our emotional cravings to love and be loved, our physical drives for sex, food, and drink, our urgings for artistic and scientific expression, and our spiritual hunger for meaning and comfort in a confusing universe all mix and mingle to produce a global and irresistable desire to be happy.

"What, therefore, does it mean if this ultimate goal is the product not of our many vaunted efforts but of the architecture of our brains, the ebb and flow of our neurotransmitters, and the unique constellation of our genes? Are our choices in life, our efforts, and our experiences irrelevant to our happiness, or do they count for something? If so, what? If happiness is even only partially related to neurology, can we control our brains, adjust our neurotransmitters, and tinker with out wiring so that we might be happier than we are now?"

To put it succinctly, Braun is investigating "the nature of the biological underpinnings of happiness, and the degree to which happiness can, or cannot, be found in a pill." To do so, he proceeds in a logical manner to examine a string of related issues, using the experiences of individuals to humanize the more theoretical themes addressed by the scientists he interviews.

After an initial chapter that reveals that Eli Lilly, Merck, and other pharmaceutical companies are in a cut-throat race to develop the next generation of mood-elevating drugs, Braun looks at happiness itself, examining what it means and to what degree it's based on biology. ". . . [H]appiness arises from a continuous interaction between one's environment (relationships, work, physical health, upbringing) and one's temperament, the inborn tendency towards optimism or pessimism, cheerfulness or dourness, introversion or extroversion. Internal factors such as energy level, openness to new experiences, and emotional resilience can powerfully shape life events, including the quality and character of the relationships a person forms." Repeated studies have shown that factors traditionally thought to influence happiness, such as money, age, and marriage, really don't have much influence.

Every person has a "happiness set point", a baseline mood around which our emotions oscillate. It turns out that for most people, the happiness set point is slightly above neutral, that is, most people are moderately happy by default. The drugs of the future may be able to raise this set point, possibly to adjust it "with the precision of a thermostat."

Still, our happiness set points are fundamentally rooted to a large degree in our neural machinery. Braun looks at the amazing research that is pinpointing the exact biological mechanisms of mood. To say that physical factors in our brains are entirely responsible for our moods and emotions would be absurd, but they appear to be the underlying cause. "Eventually the machinery of mood, of depression, and of happiness will be completely laid bare. All the circuitry will be revealed." At that inevitable point, Braun believes, science will be able to engineer drugs that raise our happiness set point.

Because this is going to happen sooner or later, we have to examine how to use these drugs in a wise, effective way. Where is the ideal set point? Can we be too happy? Should we obliterate sadness, fear, and other negative emotions, even though they play crucial roles in our lives? These questions are mulled over in the chapter "Listening to Depression."

The potential pay-off of such mood-enhancing drugs is huge, and the risks to the drug companies are great. This is a perfect prescription for unethical behavior, and in "Selling Happiness" Braun examines five instances where drug companies have show their true colors. "Pressure can be exerted on individual authors and entire institutions to block publications of studies unfavorable to a drug company's interests. Public 'educational' materials can distort the reality of mental illness, promulgate outright falsehoods, and unjustifiably tout the efficacy of drug therapy. Marketing efforts can blatantly attempt to redefine an illness to broaden the pool of potential 'patients.' And occasionally drugs can be marketed and sold despite evidence that the drugs in question could be harmful or even fatal under certain circumstances."

Braun ends by questioning what effects we will want to achieve with these drugs. What is the optimal mood (or moods, as the case may be)? How large of a role will expectations play, and how will the ways in which the drugs work affect our use of them?