Late-onset and nonlate-onset schizophrenia: A comparison of clinical characteristics in a multicenter study.

Data are scarce regarding the potential clinical differences between non-late onset schizophrenia (NLOS, i.e., disorder occurring before 40 years of age), late-onset schizophrenia (LOS, occurring between ages 40 and 60 years) and very-late-onset schizophrenia-like psychosis (VLOSLP, occurring after 60 years of age). Furthermore, previous research compared LOS patients with non-age matched NLOS patients. In this study, we sought to examine potential clinical differences between patients of similar age with LOS and NLOS. This is a cross-sectional multicentre study that recruited in- and outpatients older adults (aged ≥55 years) with an ICD-10 diagnosis of schizophrenia or schizoaffective disorder with NLOS and LOS. Sociodemographic and clinical characteristics, comorbidity, psychotropic medications, quality of life, functioning, and mental health care utilization were drawn for comparison. Two hundred seventy-two participants (79.8%) had NLOS, 61 (17.9%) LOS, and 8 (2.3%) VLOSLP. LOS was significantly and independently associated with greater severity of emotional withdrawal and lower severity of depression (all p < 0.05). However, the magnitude of these associations was modest, with significant adjusted odds ratios ranging from 0.71 to 1.24, and there were no significant between-group differences in other characteristics. In an age-matched multicenter sample of elderly patients with schizophrenia, older adults with LOS were largely similar to older adults with NLOS in terms of clinical characteristics. The few differences observed may be at least partially related to symptom fluctuation with time. Implications of these findings for pharmacological and nonpharmacological management is yet to be determined