Dopamine supersensitivity as a result of sustained antipsychotic treatment can lead to compulsive drug seeking and drug-taking behavior, according to the theory offered by a member of the Faculty of Medicine at the University of Montreal. The paper proposes that supersensitivity “can enhance the rewarding and incentive motivational effects of drugs and reward cues,” thus helping to explain why patients with a schizophrenia diagnosis so often present with a co-morbid drug problem. The paper can be found online in Progress in Neuro-Psychopharmacology and Biological Psychiatry.
I don’t really understand this theory. The supposed supersensitivity thing relates to brain compensating for the dopamine blocking caused by drugs. It doesn’t mean that the dopamine systems become more active than normal when on neuroleptics. If neuroleptics cause use of drugs such as nicotine, I’d guess that it may be because neuroleptics make you feel like shit and people may use drugs to counter the dulling effects of neuroleptics, to get at least some reward, focus, etc.