OVERVIEW - BIOLOGICAL PROCESSES RELEVANT TO DRUGS OF DEPENDENCE

Key points are highlighted from five papers that address biological pr ocesses underlying the actions of opiates, CNS stimulants, nicotine, a lcohol, and benzodiazepines. It is noteworthy that: (1) positive and n egative reinforcement are common processes underlying actions of drugs of dependence; (2) dopaminergic systems in the ventral tegmental area of the brain seem to be involved in the positive reinforcement of dru gs of dependence; (3) GABA also may be involved in this positive reinf orcement; (4) receptor sensitization and desensitization may be involv ed in the actions of drugs of dependence; (5) noradrenalin, 5-HT, ACh, NMDA and corticosteroids also may be involved in drug dependence; (6) motivational systems and processes in addition to positive and negati ve reinforcement deserve increased research attention; and (7) there m ay be genetic-based individual differences in drug dependence processe s.