Nocebos often cause a physical effect, but it's not a physically produced effect. What's the cause? In many cases, it's an unanswered question.

The doctor-patient relationship is critical to the placebo effect.

There seem to be many causes of depression. One cause is profound loss, grief. Economic hardship we know is linked to depression. We don't have a full picture.

Depression is a serious problem, but drugs are not the answer. In the long run, psychotherapy is both cheaper and more effective, even for very serious levels of depression. Physical exercise and self-help books based on CBT can also be useful, either alone or in combination with therapy. Reducing social and economic inequality would also reduce the incidence of depression.

I do a lot of research on the placebo effect, not just in depression but in irritable bowel syndrome, pain, arthritis of the knee, migraine, asthma.

Perhaps anti-depressants should be best reserved for the very extreme cases and, more importantly, for those who do not respond to alternative forms of interventions.