Obsessivecompulsive symptoms with olanzapine

The emergence or exacerbation of obsessive– compulsive (OC) symptoms during treatment with atypical antipsychotics, mostly clozapine, has been documented by numerous case reports (reviewed by Lykouras et al., 2003). In six recent reports involving nine cases, (Jonkers and deHaan, 2002; Lykouras et al., 2003) olanzapine was found either to cause de novo emergence or to exacerbate OC symptoms. In six of these cases olanzapine caused exacerbation and in three cases caused de novo emergence of OC symptoms. We report three more cases, one with schizophrenia, one with schizophrenia comorbid with major depression and one with bipolar I disorder, in which olanzapine caused de novo emergence of OC symptoms. The last case is the second report of de novo emergence of OC symptoms in a non-psychotic patient without comorbid psychotic symptoms during treatment with olanzapine.