The association between schizophrenia and smoking: Unexplained by either the illness or the prodromal period

The cumulative hazard curves for schizophrenia, mood disorders and controls were significantly different (p < 0.001), even after controlling for gender and education (p < 0.001). After excluding the patients who started smoking within 5 years of starting psychiatric medication, the cumulative hazard curve for schizophrenia patients was significantly different from that for ever-smoker controls (p = 0.002), even after adjusting for gender and education (p = 0.03).