Lost Connections

Biology, environment or a combination of both can cause mental depression, which is more complicated than having bad brain chemistry.

Prescription antidepressants became mainstream in the 1990s, but their use started as early as 1952 when doctors noticed that a tuberculosis drug made patients suddenly feel euphoric. By the 1970s, doctors thought low levels of serotonin might cause depression, a theory that persists. The mainstream scientific community identified two kinds of depression: “endogenous” and “reactive.” Some type of malfunction of the brain or body causes endogenous depression. A person’s environment or personal experience can cause “reactive depression.”

In the 1970s, anthropologist George Brown and therapist and researcher Tirril Harris interviewed women in Camberwell, a working-class area of South London. While 114 of these women had a diagnosis of depression, 344 women from the same area didn’t. Brown and Harris studied both groups for a year. They interviewed the women multiple times, asking if they had experienced severe losses or negative events in the year before they became depressed. The researchers labeled negative events as “difficulties” and...