Sex differences in disinhibition and its relationship to physical abuse in a sample of stimulant-dependent patients.

Research suggests that impulsivity is a vulnerability factor for developing stimulant dependence, that women develop dependence more quickly than men, and that physical abuse can increase impulsivity and may have greater adverse health consequences in women. This study sought to tie these findings together by evaluating: (1) sex differences in disinhibition prior to lifetime initiation of stimulant abuse and (2) the relationship between physical abuse and disinhibition in stimulant-dependent patients. The Frontal Systems Behavior Scale (FrSBe) is a reliable and valid self-report assessment of three neurobehavioral domains associated with frontal systems functioning (Apathy, Disinhibition, and Executive Dysfunction, summer for a Total), that assesses pre-morbid functioning and has a specific cutoff for defining clinically significant abnormalities. As part of the CTN ancillary study CTN-0031-A-1, “An Evaluation of Neurocognitive Function, Oxidative Damage, and Their Association with Treatment Outcomes in Methamphetamine and Cocaine Abusers,” six sites evaluating 12-step facilitation for stimulant abusers obtained the FrSBe from 118 methamphetamine- and/or cocaine-dependent participants. Lifetime physical abuse was measured by the Addiction Severity Index (ASI). The proportion reporting clinical significant disinhibition was significantly higher in women (64.95) than in men (45%), with no significant difference on the other FrSBe scales. Physical abuse in women, but not men, was associated with worse functioning, with physically abused, relative to non-abused, women having a significantly greater proportion with clinically significant disinhibition (p<0.01) and total neurobehavioral abnormalities (p<0.01).

Conclusions: These findings suggest that women may have significantly greater disinhibition than men prior to lifetime initiation of stimulant abuse and that physical abuse in women is associated with greater disinhibition. A finding of poorer functioning in physically abused, relative to non-abused, women and no poorer functioning observed in abused, relative to non-abused, men is consistent with research finding that childhood abuse may have more adverse health consequences in women than men. This study contributes to research suggesting that impulsivity is a vulnerability trait for developing stimulant dependence.

Related protocols: CTN-0031-A-1