The Effect of Personality on Reactivity to a Tetrahydrocannabinol

Case records of 40 US Army volunteers given a synthetic tetrahydrocannabinol (THC) compound similar in structure and physiological activity to the active component of marijuana were reviewed. Significant relationships were found between the personalities of these volunteers, as measured by the Minnesota Multiphasic Personality Inventory (MMPI) and the Army General Intelligence Test (GT), and performance following administration of this compound on cognitive tests. The Hs (hypochondriasis) and Pd (psychopathic deviat) scale scores and the GT score were more strongly correlated with performance than was the dose level. MMPI and GT test interpretation of subjects resistant to the cognitive impairment caused by this compound showed them to be more intelligent and adventurous but more hostile and agressive than sensitive subjects. A possible explanation for continued use of marijuana by certain personality types is offered. (Author)