Feed

Steven Hyman, former director of the National Institute of Mental Health (2012), argued that neuroscience research in psychiatry frequently inherits the DSM's assumption that disorders are discrete entities, even though empirical boundaries between conditions are often porous. In response, Hyman and colleagues advanced the Research Domain Criteria (RDoC), which organizes psychopathology around core neurobiological domains that cut across diagnoses. In a conceptually similar direction, Blum (1995) introduced Reward Deficiency Syndrome (RDS) as a transdiagnostic construct intended to unify substance-related and behavioral addictions. To date, PubMed includes more than 1,650 reports referencing "reward deficiency" and 281 specifically referencing RDS. Recent genome-wide association and pharmacogenomic findings in very large cohorts (88.8 million subjects) are interpreted as supporting dopaminergic dysregulation as a key phenotype underlying RDS vulnerability. The Genetic Addiction Risk Severity (GARS^®) panel was developed to estimate liability for RDS and "preaddiction." Notably, many conditions listed in DSM-5 share overlapping genetic polymorphisms, with frequent convergence on pathways involved in dopaminergic neurotransmission. Building on this framework, we propose a biphasic prevention and treatment strategy for both substance (e.g., alcohol, nicotine) and non-substance (e.g., highly palatable food/glucose-related) addictive behaviors. In the acute setting, harm-reduction approaches may require targeted modulation of postsynaptic dopamine receptors (D1-D5) within the nucleus accumbens (NAc). Over longer time horizons, however, durable recovery may depend on restoring dopamine signaling-specifically, promoting dopamine activation and release within the NAc to support dopamine homeostasis. Failure to balance short-term and long-term dopaminergic interventions may contribute to affective instability, maladaptive behavior, and, in vulnerable individuals, suicidal ideation. Individuals with serotonergic/dopaminergic receptor deficits and/or high catechol-O-methyltransferase (COMT) activity may be more likely to self-medicate using substances or behaviors that transiently increase dopamine release. A growing body of evidence suggests that increasing D2 receptor expression in genetically vulnerable populations could reduce addictive risk. Although D2 agonists can downregulate receptors in vivo, in vitro work indicates that sustained stimulation may promote receptor proliferation, and gene-transfer studies producing DRD2 overexpression reduce alcohol and cocaine seeking in rodent models. Finally, naturalistic dopaminergic repletion strategies may represent a safer long-term approach to normalize dopaminergic function, support recovery, and improve quality of life across RDS-related behaviors. (WC 286).