In the 1950s the tranquilizers, such as reserpine and Thorazine, were introduced. Lithium for the treatment of bipolar disorder as well as for clinical depression gradually became popular in the early 1970s. These elevate serotonin, one of the main chemicals used in the brain to signal from one nerve cell to another. For reasons that are poorly under- stood, higher serotonin levels tend to remove depression and to reduce the impulse toward violence in most people. The new chemical approach to mental illness has had profound effects on society.
Fewer people are in mental hospitals and most who are there stay only for a short time.
In many cases, however, the former patients do not go back to the hospital but find themselves homeless as a result of their illness. People also became addicted to tranquilizers, adding yet another drug to Western society in which drugs were already perceived as a leading problem.