Reduction of HIV risk behavior with transcranial magnetic stimulation

National Institute On Drug Abuse

Investigators

Abstract

Substance use disorders, especially cocaine use, is associated with higher levels of HIV risk behaviors. The dorsolateral prefrontal cortex (dlPFC) has been implicated in cognitive control and decision making in a variety of behavioral disorders including substance use disorders and risky decision-making in general. Transcranial magnetic stimulation (TMS) has shown promise in treating cocaine use disorder (CUD) individuals. In particular, individuals treated with stimulatory TMS to the left dlPFC report an enhanced ability to exert control over their cocaine use, which generalizes to some extent to other drug use. We hypothesize that the benefits of increased control over behavior may also generalize to other domains such as HIV-risk behaviors. We therefore propose to assess HIV-risk behaviors before and after a TMS treatment course in individuals with CUD. We are developing a protocol to investigate whether TMS of the left dlPFC reduces HIV risk behavior. We will administer a modified HIV Risk-Taking Behaviour Scale, an 11-item interview-based assessment, with a 12th item added to account for anal sex with and without condom use. It will be administered at baseline and monthly throughout the 6-month follow-up period. This assessment will track risk behaviors related directly to drug use as well as risk behaviors related to sexual activity. These two areas have been found to account for the increased risk of contracting HIV in drug-using populations. We will treat CUD participants with real intermittent theta-burst stimulation (iTBS) or sham iTBS over a 2-3 week period followed by 11 weeks of contingency management as the treatment-as-usual for all participants. Since the HIV Risk-Taking Behaviour Scale contains separate items for risky behaviors directly related to drug use and risky behaviors related to sexual activity, we will be able to analyze changes in risky behavior in these two domains separately. This will allow for some assessment of changes in HIV risk behaviors that are not directly a consequence of the drug use, which we expect to improve in both groups during the contingency management phase.