[Addiction and schizophrenia. Nosological, clinical and therapeutic questions. 1. Alcoholism and schizophrenia].

The scientific discussion on the interrelationship of "alcoholism and psychosis" has been dominated by nosological problems for years. Alcohol hallucinosis, a comparatively rare psychosis in chronic alcoholism, can mimic the symptomatology of paranoid schizophrenia. The clinical features (vivid acoustic hallucinations and fear) are often inconclusive, as, unlike other organic psychoses, alcohol hallucinosis does not entail clouding of sensorium and disorientation. On the one hand follow-up studies suggest that alcohol hallucinosis in some cases can take a chronic schizophrenia-like course. Especially in these cases differential diagnosis between both conditions can be difficult. On the other hand a number of recent clinical studies suggest high prevalence rates for substance and esp. alcohol abuse and dependence in schizophrenics. Different approaches account for limitations in comparing the results. In most of the studies prevalence estimates for alcohol abuse and dependence range from 12-43%. In some highly selected clinical populations even higher prevalence estimates have been reported. Epidemiological studies such as the "Epidemiological Catchment Area Study" equally are in support of an appr. 4-fold increased risk for alcoholism in schizophrenics. Schizophrenics with alcohol abuse differ from non-abusing schizophrenics in a variety of clinical symptoms and features. With respect to psychopathological symptomatology schizophrenics with an additional alcohol abuse or dependence show more "positive", psychotic and less "negative" symptoms. Some findings suggest that in comparison with other schizophrenics, dual diagnosis schizophrenics may be superior in terms of a better premorbid functioning. However, during course of illness higher (re-) hospitalization rates and higher rates of suicide attempts have been reported; likewise, aggressivity and delinquency have been encountered. In this review clinical and diagnostic questions concerning the interrelationship between alcoholism and schizophrenic psychosis are discussed and some principles of psychopharmacotherapy in dual diagnosis schizophrenics are outlined.