Incidence of hospitalised schizophrenia in Finland since 1980: decreasing and increasing again

Background It is suggested that the incidence of schizophrenia is decreasing. However, changes in the number of psychiatric beds available and diagnostic practice have not always been taken into account. We studied the annual firstadmission rate (per 100,000) for schizophrenia (FARsch) during a rapid deinstitutionalisation period in Finland. Method From the National Finnish Hospital discharge register, we identified all 30,041, 15- to 64-year-old patients admitted for the first time with schizophrenia to hospitals in Finland between 1980 and 2003. Results FARsch decreased from 56.39 in 1980 to 29.51 in 1991 and slightly increased thereafter. Changes in FARsch corresponded with changes in all admissions. FARsch was higher when using ICD-8, but lower when DSM-IIIR and ICD-10 were used. Conclusion Changes in the number of psychiatric beds available, admission policy and diagnostic practice may explain the majority of variations in FARsch. Possibly, increased use of illegal drugs and improved treatment of depression are reflected in the increase in FARsch.