The neurobiology of drug addiction: Recent advances and new intervention strategies
For years, the neurobiology of drug addiction was characterized by the short-term modulation of different neurotransmission systems, therapeutic strategies directly targeting the receptors that are bound by substances. These approaches have helped to improve the treatment of drug intoxication and withdrawal, while promoting access to a broad array of psychosocial services. However, the data highlight the mixed effectiveness of these interventions to induce a sustained decrease in consumption and other symptoms of addiction, especially craving, among subgroups of individuals. Recent advances in neuroscience have led to a growing understanding of the neurobiological mechanisms underlying the vulnerability to relapse and other behaviors associated with addiction. The primarily dopaminergic and striatal hypothesis of these phenomena has been replaced by a theory incorporating the contribution of the glutamatergic, endocannabinoid and opioid systems, as well as the interaction between these various components within cortical and sub-cortical structures. The focus has moved from the short-term neurobiological changes to the long-lasting modulation of the structures involved in addiction. This paradigm shift led to the emergence of several therapeutic strategies that aim at reducing the risk of relapse by modulating specific neural circuits whose functions are altered by chronic substance use. The endocannabinoid and glutamate systems, in particular, are promising targets for the treatment of craving and relapse. This article aims to summarize some of the latest trends in the neurobiology of addiction as well as new avenues of treatment.