TY - JOUR T1 - Cerebellar motor learning deficits in medicated and medication-free men with recent-onset schizophrenia JF - Journal of Psychiatry and Neuroscience JO - J Psychiatry Neurosci SP - E3 LP - E11 DO - 10.1503/jpn.120205 VL - 39 IS - 1 AU - Michael Coesmans AU - Christian H. Röder AU - Albertine E. Smit AU - Sebastiaan K.E. Koekkoek AU - Chris I. De Zeeuw AU - Maarten A. Frens AU - Josef N. van der Geest Y1 - 2014/01/01 UR - http://jpn.ca/content/39/1/E3.abstract N2 - Background: The notion that cerebellar deficits may underlie clinical symptoms in people with schizophrenia is tested by evaluating 2 forms of cerebellar learning in patients with recent-onset schizophrenia. A potential medication effect is evaluated by including patients with or without antipsychotics.Methods: We assessed saccadic eye movement adaptation and eyeblink conditioning in men with recent-onset schizophrenia who were taking antipsychotic medication or who were antipsychotic-free and in age-matched controls.Results: We included 39 men with schizophrenia (10 who were taking clozapine, 16 who were taking haloperidol and 13 who were antipsychotic-free) and 29 controls in our study. All participants showed significant saccadic adaptation. Adaptation strength did not differ between healthy controls and men with schizophrenia. The speed of saccade adaptation, however, was significantly lower in men with schizophrenia. They showed a significantly lower increase in the number of conditioned eyeblink responses. Over all experiments, no consistent effects of medication were observed. These outcomes did not correlate with age, years of education, psychopathology or dose of anti psychotics.Limitations As patients were not randomized for treatment, an influence of confounding variables associated with medication status cannot be excluded. Individual patients also varied along the schizophrenia spectrum despite the relative homogeneity with respect to onset of illness and short usage of medication. Finally, the relatively small number of participants may have concealed effects as a result of insufficient statistical power.Conclusion: We found several cerebellar learning deficits in men with schizophrenia that we cannot attribute to the use of antipsychotics. Although this finding, combined with the fact that deficits are already present in patients with recent-onset schizophrenia, could suggest that cerebellar impairments are a trait deficit in people with schizophrenia. This should be confirmed in longitudinal studies. ER -