He is the originator of response expectancy theory, and his analyses of clinical trials of antidepressants have influenced official treatment guidelines in the United Kingdom.

The son of Jewish immigrants from Poland and Russia, Kirsch was born in New York City on March 7, 1943.

While a graduate student, he produced, in conjunction with the National Lampoon, a hit single and subsequent record album entitled The Missing White House Tapes, which were crafted by doctoring tape recordings of Richard Nixon’s speeches and press conferences during the Watergate hearings.

The theory is supported by research showing that both subjective and physiological responses can be altered by changing people’s expectancies.

[6] The theory has been applied to understanding pain, depression, anxiety disorders, asthma, addictions, and psychogenic illnesses.

[8] No evidence was cited to support this cut-off and it was criticised for being arbitrary;[9] NICE removed the specification of criteria for clinical relevance in its 2009 guidelines.