acamprosate activity addictive substances agonist alcohol craving alcohol dependence amphetamine amygdala antagonist attenuate Baclofen behaviour binding brain regions bupropion caudate CHAPTER chronic cigarette cingulate clinical cocaine dependence cognitive control consumption Copyright cues decreases disorders DLPFC dopamine neurons dopamine release dose drug effects of substances efficacy EXE Placebo exenatide Figure functioning GABA receptors GABAergic gabapentin genetic ghrelin glutamate heroin hormones humans increase induced inhibition inhibitory involved medications methadone methamphetamine methylphenidate midbrain motivation mu opioid receptor NAcc nAChRs naltrexone neural neurons neuroplasticity Neuropsychopharmacology neurotransmitter nicotine abstinence nicotine addiction NMDA receptor nucleus accumbens Opiates opioid receptor orbitofrontal cortex orexin pathway permission from Elsevier Pharmacology placebo potential prefrontal cortex presynaptic putamen reducing cocaine reinforcing effects relapse Reprinted Research reuptake role shown significantly smoking stimulants striatal subjective effects substance abuse substance addiction substances of abuse substances of addiction suggests synaptic Tiagabine tobacco Topiramate treatment varenicline ventral striatum Volkow ND withdrawal