What Is Mental Illness?

Dave Munger weighs in on proposed changes to the Diagnostic and Statistical Manual of Mental Disorders:

One of the biggest changes in their proposed definition is the statement that a mental disorder “reflects an underlying psychobiological dysfunction.” They are, in essence, saying that there is nothing truly “mental” about these disordersthe disorders are a result of physical problems in the brain. This is a huge acknowledgment for a field that once thrived on such vacuous concepts as the “id” and the “superego.” ...

Doctors don’t define a broken leg as “unable to walk,” so why should psychiatrists define a mental disorder solely based on the behavioral symptoms?