Jessica Leigh Johnston in National Post:
Have you ever heard of the Rosenhan experiment? Psychologist David Rosenhan, in 1973, feigned mental illness in order to be institutionalized. Seven of his associates did the same. But after their internment, they acted completely normal. They even took notes, openly, about the experiment they were conducting. The asylum staff took this behaviour to be further evidence of their madness. Rosenhan and his associates were only released after claiming to have taken their antipsychotic meds, which they had covertly flushed down the toilets. Once judged insane — on limited evidence — the system was incapable of viewing their behaviour normally. The experiment had a second part, which was even more disturbing than the first. When Rosenhan published the results of his first experiment, uproar occurred. During the controversy, one hospital claimed to be impervious to such errors. Rosenhan said, OK, let’s see about that. He told them he’d send them a number of pseudo-patients like the ones in his previous experiment. A few months later, they triumphantly responded that they had caught some of his fakes. Rosenhan then confessed that he had, in fact, sent no fake patients. The hospital had been turning away people with real symptoms.
So: psychiatry is fairly fallible. Mental institutions make errors about their patients. Once you’ve admitted someone, it actually becomes more difficult, in some ways, to figure out how sane they are: you’re sticking them in an extraordinary environment where it may be to their advantage to feign unusual behaviours.