ABSTRACT
In Europe, the first so-called atypical antipsychotic, clozapine, was studied as early as the years 1961 and 1962 at the universities of Bern/Switzerland as well as Vienna/ Austria in chronic schizophrenia (1), and the first beneficial effects of clozapine (double-blind study in comparison to levomepromazin) in mania and acute schizophrenia were published by Angst et al. (2) in 1971. Thereafter, clozapine was mainly used in acute schizophrenia, and it was not until the mid-1990s that atypical antipsychotics were studied systematically for treatment of bipolar disorder (3). There were a few early case reports about risperidone in the beginning 1990s, which even suggested that risperidone causes manic switches in specifically vulnerable patients (4), a finding which was opposed soon thereafter by observations obtained in larger sample sizes (5).
