According to a meta-analytic study published in the journal Neuropsychology Review, obsessive-compulsive disorder is not associated with a higher intelligence quotient (IQ), a myth popularized by Sigmund Freud.
A study by Abramovitch et al is the first analysis of existing data on the link between IQ and OCD sufferers verses the general population. Image credit: AirPix.
“Obsessive compulsive disorder (OCD) is associated with a moderate degree of underperformance on cognitive tests, including deficient processing speed,” said Texas State University researcher Dr. Amitai Abramovitch and colleagues.
“However, despite little research focusing on IQ in OCD, it has long been speculated that the disorder is associated with elevated intellectual capacity.”
The scientists conducted a meta-analysis of all the available literature on IQ in OCD samples versus non-psychiatric controls (98 studies), and found that contrary to the prevailing myth, OCD is not associated with superior IQ, but with normative IQ that is slightly lower compared to control samples.
They suggested that the small reduction in IQ scores in OCD sufferers may be largely attributed to OCD-related slowness and not to intellectual ability.
“Future IQ assessments of individuals with OCD should focus on verbal and not performance IQ — a score heavily influenced by slowness,” the authors said.
They also tracked the origins of the myth to the French philosopher, physician and psychologist Pierre Janet in 1903, but it was Sigmund Freud who popularized the hypothesis in 1909.
“Although this myth was never studied empirically until now, it is still a widely held belief among mental-health professionals, OCD sufferers and the general public,” said study co-author Dr. Gideon Anholt, a senior lecturer in the Department of Psychology at Ben Gurion University in Beer Sheva, Israel.
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A. Abramovitch et al. Meta-Analysis of Intelligence Quotient (IQ) in Obsessive-Compulsive Disorder. Neuropsychology Review, published online September 1, 2017; doi: 10.1007/s11065-017-9358-0
