The Lobotomist: A Maverick Medical Genius and His Tragic Quest to Rid the World of Mental Illness
by Jack El-Hai
362pp, Wiley, £19.99

There are various ways to carry out a lobotomy, but one of the first methods, invented by the Portuguese neurologist Egas Moniz, involves drilling two holes in the forehead, one above each eye. You then insert a special instrument called a leucotome through each hole, one after the other, so that it penetrates the frontal lobes of the brain. Pressing a button at the top of the instrument causes a wire loop to extend from the other end, which is then rotated to slice through a section of neural fibres. You then withdraw the loop back into the leucotome, pull the instrument out by a centimetre, and make another cut. Repeat once more, and then reinsert the leucotome through the same hole at another angle, and make three more cuts, to make a total of six cuts on each of the two frontal lobes.

If this sounds like a stab in the dark, that's because it is. The brain contains about 10bn neurons, each of which is connected with up to 1,000 other neurons, forming a network of such baffling complexity that we are still only beginning to understand it. Yet 70 years ago, when our knowledge of the brain was even more primitive than it is today, an American surgeon called Walter Freeman threw caution to the wind and inaugurated one of the most notorious chapters in the history of psychiatry. Between 1936 and his death in 1972, Freeman performed more than 3,000 lobotomies, mainly on patients with certain extreme forms of agitation and depression who had previously been regarded as incurable. By 1950, about 5,000 lobotomies per year were being performed in America, and more than 1,000 a year in Britain.

The amazing thing, given the crude nature of the operation, was its high success rate, with between 40% and 50% of patients showing significant improvement. Many schizophrenic patients, who would otherwise have remained in hospital for the rest of their lives, were able to go home and lead relatively normal lives. Adverse reactions were rare, with only 5% or 6% of those who had lobotomies getting worse or dying. In fact, it was only the development of new drugs to treat schizophrenia and depression in the mid-50s that led to the lobotomy gradually going out of favour.

In 1936, of course, when Freeman began conducting lobotomies, he had no statistics on which to base his practice - just blind faith. If you want to know what kind of man takes such a huge gamble with other people's brains, Jack El-Hai's new biography of Freeman offers an answer.

When he began work on the book, El-Hai confesses he was prepared to condemn Freeman as cruel and unprincipled, but as he discovered more about him he came to see him in a more favourable light. There is nothing particularly unusual about this: you can probably develop some affection for almost anyone if you spend several years delving into the most intimate details of their life story. The real test is whether the subject of a biography arouses the same affection in its readers.

I'm afraid Freeman fails this test. I did not come away from El-Hai's book feeling Freeman was an evil man, but I did not develop much affection for him. He was obsessed with his career, desperate for recognition, and completely lacking in glamour or flair. As a schoolboy, he was shy and unathletic. He found girls "bothersome", and didn't go on a date until he was in medical school. In short, he was a bit of a dork.

These characteristics may not make Freeman a very interesting subject for a biography, but they did make him an ideal candidate for a scientific career. And so we follow him as he plods along the shabby treadmill of scientific preferment. Above all, the impression one gets is of a man who was more interested in making a name for himself than in alleviating the suffering of his patients.

For those with an interest in the history of psychiatry, this book offers a well-researched account of psychosurgery in the mid-20th century. But for the general reader, the man who emerges from these pages is not likely to prove inspiring or engaging.

• Dylan Evans is the author of Placebo: Mind Over Matter in Modern Medicine (HarperCollins)