Tanya Marie Luhrmann explains how our understanding of schizophrenia has shifted over the years:
[S]chizophrenia now appears to be a complex outcome of many unrelated causes—the genes you inherit, but also whether your mother fell ill during her pregnancy, whether you got beaten up as a child or were stressed as an adolescent, even how much sun your skin has seen. It’s not just about the brain. It’s not just about genes. In fact, schizophrenia looks more and more like diabetes. A messy array of risk factors predisposes someone to develop diabetes: smoking, being overweight, collecting fat around the middle rather than on the hips, high blood pressure, and yes, family history. These risk factors are not intrinsically linked. Some of them have something to do with genes, but most do not. They hang together so loosely that physicians now speak of a metabolic “syndrome,” something far looser and vaguer than an “illness,” let alone a “disease.” Psychiatric researchers increasingly think about schizophrenia in similar terms.