Addictions: Pathogenesis Mesolimbic Dopaminergic Pathway: • Dopaminergic neurons in Ventral Tegmental Area (VTA) in midbrain under continuous GABA inhibition • When stimulated by reinforcing stimuli (food, sex, drugs), the VTA releases dopamine into the Nucleus Accumbens (NAc) • The NAC receives additional input from amygdala and hippocampus (emotional context, affective response) • The NAC projects to the basal ganglia (coordinating motivated behaviour) which projects to the prefrontal cortex (processing reward, decision making) • Drug-induced increase in dopamine in this pathway motivates further drug use by triggering feelings Of reward or pleasure • Occasional recreational use -> impulsive drug administration and poor control -> chronic habitual compulsive use • Chronic drug use leads to adaptive morphological changes of neurons in dopamine regulated circuits, which influence addictive behaviours -> Addiction (Pathological Pattern: Impaired Control, Risky use, Social Impairment, Tolerance and Withdrawal) #Drug #Addiction #Pathophysiology #Psychiatry #Mesolimbic
