Neuro-chemical activation of brain reward meso-limbic circuitry is associated with relapse prevention and drug hunger: a hypothesis

Background

It is no surprise that it has taken over four decades to confirm and extend the crucial role of dopamine and related genes and gene deficits in the etiology of risk for drug dependence. Hundreds of studies, enabled by neuroscience neuroimaging and genetic advances, have been reported. While dopamine theories have been reported, confirmed, replicated and replicated again, changes have been slow to move from the bench to the bedside. Unlike penicillin used to target certain infections, addiction requires the consent, motivation and enthusiastic participation of the patient. Clearly, current treatment has not caught up with advances in the science. In-patient and out-patient treatment still relies on detoxification, abstinence and 12 step programs. Addiction is a chronic and relapsing disease. Addiction treatment can be reported as cures at 3 or 6 weeks, only to be clearly failures at 1 or 5 years. The logical standard of care should focus on detoxifying, stabilizing and returning the patient to the pre-loss of control or pre-addiction neurochemical state.

Method

Pre-clinical and clinical data on neurochemistry and neurogenetics of Substance Use Disorder (SUD) as it relates to both relapse and drug hunger has been reviewed.

Results

We are proposing herein that efforts to physiologically integrate known neural mechanisms with other psychotherapeutic treatment options to combat relapse should be encouraged. It is well known that after prolonged abstinence, recovered addicts are particularly vulnerable to relapse. Individuals who use their drug of choice after abstinence experience a powerful euphoria that can quickly precipitate a full-blown relapse. While a biological explanation for this conundrum has remained elusive, we hypothesize that this clinically observed “supersensitivity” might be the result of pre-morbid or state genetic hypodopaminergic polymorphisms.

Hypothesis

We are proposing that recent studies have indicated that genetic, personality and environmental factors are predictors of drug use in adolescents. Exploration of various treatment approaches for the most part reveal poor outcomes in terms of relapse prevention and continued drug hunger. The authors are proposing a new paradigm shift in residential, non-residential and aftercare involving the incorporation of genetic testing to identify risk alleles coupled with D2 receptor stimulation using neuroadatogen amino acid precursor enkephlinase – catecholamine-methyltransferase (COMT) inhibition therapy. A natural but therapeutic nutraceutical formulation potentially induces DA release could cause the induction of D2-directed mRNA and proliferation of D2 receptors in the human. We further hypothesize that this proliferation of D2 receptors in turn will induce the attenuation of drug-like craving behavior. Finally, pharmacological therapies have had limited success because these powerful agents have focused on maintenance or interference with drug euphoria rather than correcting or compensating for pre-morbid dopamine system deficits These concepts await further confirmation via required neuro-imaging studies.