The beginning of the piece seems fairly devastating: One guy, Robert Spitzer, had a lot to do with writing the Diagnostic and Statistical Manual of Mental Disorders (DSM) that has been in increasingly widespread use.
The manual’s flashy exactitude, however exaggerated, dovetailed profitably with the interests of drug companies, which were further revolutionizing psychiatry with psychoactive drugs, starting with the tranquillizer Thorazine in 1954 and by no means peaking with Prozac in 1987. It all helped popularize the theory that mental illness is caused by chemical imbalances in the brain.
Brown hedges a bit as to whether the drugs are more or less harmless, like a placebo, or positively harmful, especially in the medium to long term. And towards the end he lets mainstream psychiatrists speak, saying they base their work more and more on objective evidence, and their science is at an early stage compared to other branches of medicine. There is little elaboration of the possibility that somewhat eccentric people are going to be branded as somehow not normal, and encouraged to take dangerous drugs; nor that psychiatry is causing or worsening an epidemic of serious mental illness.