Psychosocial stress enhances non-drug-related positive memory retrieval in male abstinent heroin addicts

Abstract

Stress exposure in addicted individuals is known to provoke drug craving, presumably through a memory-like process, but less is known about the effects of stress on non-drug-related affective memory retrieval per se in such individuals, which is likely to provide important insights into therapy for relapse. In present study, we explored the effect of stress on retrieval of neutral and emotionally valenced (positive and negative) words in abstinent heroin addicts. In present study, 28 male inpatient abstinent heroin addicts and 20 sex-, age-, education- and economic status-matched healthy control participants were assessed for 24h delayed recall of valenced and neutral word lists on two occasions 4 weeks apart-once in a nonstress control condition, once after exposure to the Trier Social Stress Test in a counterbalanced design. In addition, attention, working memory, blood pressure, heart rate and salivary cortisol were assessed. We found acute stress at the time of word list recall enhanced retrieval of positively valenced words, but no effect on negative and neutral word retrieval in abstinent heroin addicts was observed. No changes were detected for attention and working memory. The stressor induced a significant increase in salivary free cortisol, blood pressure and heart rate. Stress can enhance non-drug-related positive memory in abstinent heroin addicts. Our findings will provide richer information in understanding dysregulation of their emotional memory processing under stress and hopefully provide insight into designing improved treatments for drug addiction.