Generalization of effects of environmental enrichment on seeking for different classes of drugs of abuse.

Background: Addiction is a chronic disease characterized by persistent vulnerability to relapse during abstinence. In animal models of addiction, accumulating evidence suggests that exposure to environmental enrichment (EE) during periods of abstinence can have curative effects on addiction and reduce the risks of relapse. However, until present most studies have mainly focused on cocaine. In this study, we investigated whether EE could have beneficial effects on cue-induced seeking for several psychoactive drugs belonging to different pharmacological classes such as methamphetamine (METH), heroin (HER) and nicotine (NIC).

Methods: After self-administration training of METH, HER and NIC, rats were housed in enriched (EE) or standard environments (SE) for 21-28 days of forced abstinence and then drug-seeking behavior was assessed in the absence of the drug.

Results: We found that, compared to SE housing, exposure to EE reduced drug seeking behavior for all drugs tested.

Conclusions: These findings suggest that the anti-craving effects of EE are general for a wide variety of drugs and support the hypothesis that environmental stimulation may be a general intervention for attenuating relapse in humans.