Objective: Cigarette smoking remains the greatest preventable cause of death and disease in the United States. Tobacco is defined as a psychoactive substance causing mental and behavioural disease by World Health Organisation. Only about 1% of the population is affected by schizophrenia, but the prevalence of nicotine dependence among schizophrenic patients is very high (58 %-92 %). It has been suggested that, cigarette has beneficial effects on positive and negative symptoms, cognitive skills and extrapyramidal side effects via reducing antipsychotic blood levels.

Methods: In this study it was evaluated previous hospitalisation records of 502 patients with schizophrenia, and was investigated that how patiens affected of this dependence.

Results: The number of hospitalisation in cigarette smoker group were 2-6 times more than the non smoker group. In cigarette smoking group, it was found that comorbid alcohol abuse or dependence was 3-4 times, comorbid substance abuse or dependence was 5 times more then non-smokers.

Conclusions: This finding may suggest that the smoker group has more severe psychopatology or cigarette smoking worsens the psychopatology by itself.