Limbic System Activity and Drug Dreaming in Drug-Addicted Subjects

Abstract

Several studies have noticed that drug-addicted subjects frequently report dreams the contents of which are related to their abnormal urge to use the drug to which they are addicted (i.e., drug craving). In B. Johnson’s hypothesis, the mesolimbic-mesocortical dopaminergic system, identified by Solms as essential in the generation of dreaming, is exactly the one that, when upregulated by addictive drugs exposure, is responsible for drug craving and related drug dreams. These dopaminergic circuits arise from the ventral tegmentum and have substantial projections in limbic structures. The aim of this study is to investigate the limbic activity, assessed by means of the Limbic System Checklist, LSCL-33, of drug-addicted subjects in relation to their drug dreaming. Consistent with Johnson’s hypothesis, results show that drug-addicted subjects who reported drug dreams had significantly higher LSCL-33 scores than did the control group, which did not have drug dreams. The LSCL-33 scores of drug-addicted subjects are similar to those obtained from temporal-lobe epilepsy subjects. The results of the study provide a clinical exemplification of the neuropsychoanalytic model and are consistent with previous literature that found a correlation between limbic hyperactivity and dreams with a strong emotional/motivational connotation. From the neurobiological background of the drug dreams observed in this study and in previous literature, an account of drug-dream onset is proposed.