Characteristics of prospective memory deficits in HIV-seropositive substance-dependent individuals: Preliminary observations

Abstract

The construct of “prospective memory” (PM) refers to a type of episodic memory for a future intention or “remembering what one must do.” This function has been proposed as a candidate mechanism underlying behaviors of critical importance in HIV disease, including adherence with medication regimens and continued engagement in risk behavior. We administered tasks of time-based and event-based prospective memory and control tasks of retrospective and working memory to 31 HIV-seropositive and 35 HIV-seronegative substance-dependent individuals (SDIs). We found that compared with HIV− controls HIV+ participants showed deficits in time-based but not event-based PM. Retrospective, but not working, memory performance correlated significantly with time-based PM performance. In addition, performance on the time-based PM task was a significant predictor of scores on a self-report measure of risky sexual and injection practices. These preliminary data provide new and unique findings regarding the components of executive function mediated by prefrontal cortical systems that are impaired among HIV+ SDIs and their relevance to “real-world” behaviors.

We thank Mary Beth Graham, Jose Bolanos, Pyrai Vaughan, and Joe Sangster for participant referrals, and Debbie Twomey for assistance with data entry. Dr Bechara is now at the Department of Psychology, University of Southern California. Supported by HHS R01 DA12828 to Eileen Martin and by F32 DA18522 to Raul Gonzalez.

Notes

¹ Additionally, HIV+ participants performed significantly more poorly on measures of immediate and delayed spatial memory but not on verbal paired-associate or paragraph learning. These findings are not inconsistent with previous reports of variable performance on retrospective memory tasks by HIV+ individuals (Peavy et al., 1994; Reger, Welsh, Razani, Martin, & Boone, 2002).

² As noted previously, only 10% of participants reported injecting drugs within the past 6 months; consequently, RAB scores were influenced primarily by the participants' level of self-reported sexual behavior.