1. Serious mental illness is defined by the National Institute of Mental Health to be “mental, behavioral or emotional disorder… resulting in serious functional impairment, which substantially interferes with or limits one or more major life activities.”

1. Syphilis rates are rising across the country. In 2000, there were only 6,000 cases; in 2017, there were 30,644.

2. Schizophrenia remains one of the most misused medical terms. Enter “schizophrenic” into a Google News search and you’ll land on an array of uses describing everything from Brad Pitt’s movie War Machine to Facebook’s new community guidelines—all glaringly incorrect usages.

3. A quick distinction: Psychotherapy is a more general term, one interchangeable with talk therapy (though distinct from counseling, which tends to focus on a specific issue), whereas psychoanalysis started with Freud and is “the most complex of the talking treatments,” according to the British Psychoanalytic Council.

4. I should add that after his suicide in 1990, allegations emerged that Bettelheim exaggerated his credentials, fabricated research, and abused children under his care.

1. The APA reiterated its dedication to the Goldwater rule in 2018 in response to public debates over President Donald Trump’s mental fitness, writing, “A proper psychiatric evaluation requires more than a review of television appearances, tweets, and public comments.”

1. Dr. Orne would later make waves himself when he released the transcriptions of his therapy sessions, conducted between 1956 and 1964, with poet Anne Sexton to her biographer seventeen years after her suicide.

1. Yes, most likely, according to studies on social class and diagnosis that date back fifty years. Older studies show that people with higher socioeconomic status were more likely to be diagnosed with manic depression (or bipolar disorder) than the general population. But more recent studies, however, have shown an opposite correlation.

1. Fryer would cross paths with Rosenhan in 1973 when he arranged for Rosenhan to attend a symposium at his hospital, Norristown State Hospital near Philadelphia, on the topic of “The Rights of the Mental Patient.” Another guest? Dr. Bartlett. During that same visit, Fryer also arranged for Rosenhan to go undercover as a pseudopatient at Norristown to gather more information for his unpublished book.

1. The same thing still happens today. When Stephen Paddock committed suicide after opening fire on a concert in Las Vegas in 2017, killing fifty-eight people and wounding five hundred, authorities shipped his brain to Stanford in an effort to track down any biological basis for such unthinkable evil. As of this writing, Stanford has not released the results.

1. Insanity in a legal context involves intent—it’s a question of whether or not the defendant was able to determine right from wrong during the crime. Here is the definition from Law.com: “n. mental illness of such a severe nature that a person cannot distinguish fantasy from reality, cannot conduct her/his affairs due to psychosis, or is subject to uncontrollable impulsive behavior.”

2. Another Reichian with a rumored orgone box of his own was Vermont senator Bernie Sanders. In 1969, he wrote an essay called “Cancer, Disease and Society” for the Freeman, quoting from Wilhelm Reich’s 1948 book The Cancer Biopathy, writing, as Mother Jones reported, that he was “‘very definite about the link between emotional and sexual health, and cancer,’ and he walked readers through Reich’s theory about the consequences of suppressing ‘biosexual excitation.’”

1. The American Psychiatric Association dropped the use of the Roman numeral system for DSM-5 to make it easier to add “piecemeal revisions in the future” in software updates, sociologist Andrew Scull explained.

1. Just before this book went into production and while he was preparing to move, Harry chanced upon the notes he took during his hospitalization. These notes confirmed (after much debate) which hospital Harry visited: the U.S. Public Health Service Hospital in northwest San Francisco, a federally funded research hospital that originally catered to soldiers and officers in the Navy.

1. Unless all the numbers are the same, and in this case we know they weren’t.

1. Coincidentally, David Rosenhan went undercover at Norristown State Hospital as a pseudopatient in 1973 after “On Being Sane in Insane Places” was published.

1. Some have suggested that people with schizophrenia are more likely to have antibodies directed against a common feline parasite (Toxoplasmosis gondii) that can also infect humans. Schizophrenia, studies say, is more common in countries where people keep cats.