Stress enhances retrieval of drug-related memories in abstinent heroin addicts.

Stress is associated with relapse to drugs after abstinence, but the mechanisms for this association are unclear. One mechanism may be that stress enhances abstinent addicts' recall of memories of drugs as stress relievers. This study assessed the effects of stress on free recall and cued recall of 10 heroin-related and 10 neutral words learned 24 h earlier by 102 abstinent heroin addicts. These participants were randomly assigned to three experiments that also assessed attention and working memory. Experiment 1 used a psychosocial stressor (Trier social stress test (TSST)) before testing for recall of heroin-related words. Experiment 2 added administration of the beta-adrenoceptor antagonist propranolol 1 h before the psychosocial stressor. Experiment 3 added administration of either cortisol with propranolol, cortisol alone, or propranolol alone 1 h before word recall to determine whether stress enhancement of heroin-related word recall required noradrenergic-glucocorticoid interactions. We found that free recall of heroin-related words in abstinent addicts was enhanced after stress or cortisol administration when compared with a non-stress condition or placebo, respectively, whereas these interventions had no effect on neutral word recall. beta-adrenergic blockade blocked the enhancing effect of stress or cortisol on free recall of heroin-related words. Neither stress nor cortisol affected cued recall, attention, or working memory. The potential of beta-adrenergic blockade to reduce or block stress-induced enhancement of drug-related memory retrieval may be relevant to preventing stress-induced relapse in abstinent heroin addicts.