Never Enough: The Neuroscience and Experience of Addiction

by Judith Grisel

All drugs affect multiple brain circuits, and variation in their sites of neural action accounts for their different effects. However, all addictive drugs are addictive precisely because they share the ability to stimulate the mesolimbic dopamine system. Countless studies have demonstrated that the squirt of dopamine in the nucleus accumbens from addictive substances (including chocolate and hot sauce!) is associated with the substances’ pleasurable outcome. Some, like cocaine and amphetamine, are universally effective; others seem to have a bigger influence on mesolimbic dopamine in some individuals than in others (for example, marijuana and alcohol), and some that have been labeled addictive probably aren’t. For instance, most research suggests that the psychedelic LSD does not stimulate the mesolimbic pathway. From this and related evidence, the majority of addiction researchers would argue that LSD is not an addictive drug.