Social motivational processing and interpersonal function in aging cocaine smokers

Illicit drug use among aging cohorts is increasing, yet little is known about functional impairments in older drug users. Given the importance of social integration for aging and documented social decrements in cocaine users, we examined social function and its neurocognitive substrates in aging cocaine users relative to carefully matched non-cocaine users. Regular (≥twice/week), long-term (≥15 years) cocaine smokers 50-60 years old (COCs; n = 22; four women) and controls (CTRLs; n = 19; four women) underwent standardized probes of social reward and threat processing during functional magnetic resonance imaging and a behavioral facial affect recognition task. Self-report and peer-report of daily interpersonal function were also collected. COCs, and CTRLs reporting current marijuana or alcohol use, were tested after four drug-free inpatient days. COCs had pronounced problems in daily social function relative to CTRLs indicated by both their own and their peers' reports. Compared with CTRLs, COCs had stronger amygdala responses to social threat versus control stimuli, with no other differences in social processing or cognition. Aging cocaine users appear to have marked, generalized difficulties in 'real-world' interpersonal function but largely intact social processing on laboratory-based measures when compared with appropriately matched controls and tested under well-controlled conditions. Daily social difficulties may be related to transient factors such as acute/residual drug effects or cocaine-related changes in health behaviors (e.g. disrupted sleep and poor diet). These data suggest that interpersonal function may be a valid intervention target for aging cocaine users and warrants further study in older drug users.