In the West a few centuries ago, mental illness was considered the result of personal or spiritual failure. Those who suffered were often considered punished by God, and incarcerated or otherwise treated cruelly (think of Bertha Antoinetta Mason locked away in Thornfield Manor.) In France in the early 1800s, Phillipe Pinel and Jean Etienne Esquirol introduced the idea of the traitement morale, that is, using empathy and compassion as treatments, and they began to develop basic diagnostic categories. A few years later, in Germany, Kahlbaum and Kraepelin, who worked in mental asylums, began documenting and describing psychotic and cycling mood illness. Some of their descriptions are still used as diagnostic criteria in the DSMIV today.
It's important to note that these doctors felt psychiatric illness was biological, that is part of an organic disorder of the brain, much like a stroke or epilepsy. Some of the disorders, such as hebrephrenia (a giddy type of schizophrenia found more often in young people) were extremely common back then, but incredibly rare now. Catatonia (a type of movement disorder associated with schizophrenia - either frozen movement or frenzied, uncontrolled movement) was also much, much more common in Kraepelin and Kahlbaum's catalogs than today.
Towards the end of the 19th century and the beginning of the 20th century, there was a large-scale increase in the number of psychiatric inpatients. Thousands upon thousands of people ended up in psychiatric hospitals. There was speculation at the time that the human race was "degenerating" as a result of some unknown natural selection process. Kraepelin traveled to Java and noted that mental illness was rare there, and felt the "domestication" of the human race was to blame. Unfortunately, he ignored the effects of poverty, poor hygiene, poor nutrition, and lack of education as possible causes of mental illness. His ideas were very influential, and since there was no pharmacological treatment at the time, many countries began measures such as sterilizing anyone with mental illness to stop the decline of the human race. Psychiatric authorities saw themselves as advocates of the mental health of the population (and some advocates of racial purity), rather than as medical doctors who treated individuals. (It is toward the end of this time that Weston Price made his famous journeys, and thus the name of his book, Nutrition and Physical Degeneration, and his preoccupation with the decline of physical, moral, and mental fiber, as it were, in the 1930s.)
We know what happened next. In Germany, the eugenics movement became the systematic extermination of millions of people, all for the sake of a non-existent and meaningless racial purity. Among those murdered were the mentally ill.
One who fled Nazi persecution was Sigmund Freud, and his ideas as to the cause of psychiatric illness were almost entirely different than the psychiatrists of the 18th and 19th centuries. He theorized that mental illness was caused by unconscious and repressed desires, and exacerbated by family situations (particularly problems with mothering) and coping patterns. The treatment, therefore, was therapy (back then, psychoanalysis). A large group of psychiatrists and psychologists were influenced by his ideas, and London and New York became centers of psychoanalytic thinking in the 1950s and 60s. In the next decades, psychotherapy advanced by leaps and bounds, and today there are 10 or 20 different kinds (in my opinion, the best book about the history of psychotherapy is Freud and Beyond). By the 1980s, it became clear that mental illness had both biological and psychological underpinnings. However, even to this day, there remains a false dichotomy - that all psychiatric illness can be cured if one works hard enough and has a good enough therapist, and that psychiatrists don't care about psychology or therapy and only want to stuff you full of pills. Truth be told, social, biological, and psychological underpinnings are all extremely important, and all must be kept in mind when recommending appropriate treatment.
I believe that all psychiatric illness is biologic, meaning rooted in neurotransmitters and membrane potentials, but that genetics, environment, nutrition, and psychotherapy impact how the brain works. The brain is better understood now than ever, which is to say it is still poorly understood in many respects. The vast complexity is nearly unfathomable. In my mind, the study of nutritional and evolutionary paradigms which may predispose us to psychiatric illness have been neglected in favor of psychology and the psychiatric medications. In the next post, I'll focus more on the changes in major depressive disorder over the last century, and speculate as to some nutritional causes.