O’Brien M, et al. - The frequency and range of neuropsychiatric conditions that occurred within individual first-degree and second-degree relatives of patients with amyotrophic lateral sclerosis (ALS) were investigated. In addition to schizophrenia, neuropsychiatric symptoms, including obsessive-compulsive disorder, autism, and alcoholism, occurred more frequently in ALS kindreds compared to controls. The presence of the C9orf72 repeat expansion did not fully account for this finding, implying the presence of additional pleiotropic genes associated with both ALS and neuropsychiatric disease in the Irish population.