Failure to find P50 suppression deficits in young first-episode patients with schizophrenia and clinically unaffected siblings

Objective: To evaluate whether the P50 gating deficit is present in young first-episode patients with schizophrenia and their healthy young siblings. Methods: An auditory paired-click paradigm was used to assess P50 gating in 53 patients, 27 unaffected siblings, and 28 healthy controls. P50 parameters were compared between patients, sibs, and unrelated controls by a mixed-effects regression model. Results: P50 gating was not significantly impaired in patients with schizophrenia and healthy siblings as compared with controls. Conclusions: P50 gating was not found to be significantly impaired in young first-episode schizophrenia patients and in healthy young siblings. These results are in contrast with the existing literature. We suggest that P50 gating impairment may be developmentally or age dependent.