The smoking prevalence in schizophrenia is at 70-80%, with the prevalence of cigarette smoking at initial onset of psychosis being at an estimated 58% of studied patients. Smokers with schizophrenia tend to inhale deeper, smoke for longer durations, consume higher amounts of cigarettes, and have higher nicotine dependence compared to smokers without schizophrenia. There are competing theories as to why this high association between smoking and schizophrenia exists.