Premorbid Social Functioning and Adult Schizophrenia Spectrum Disorders in the Copenhagen Perinatal Cohort

Schizophrenia is a debilitating mental illness, best known for prominent positive symptoms. In addition to positive symptoms, symptoms related to social dysfunction are also often extremely impairing. For people living with schizophrenia, higher levels of social difficulties are associated with poorer functional outcomes. Research suggests individuals with schizophrenia experience difficulties with social functioning during development prior to reaching full criteria for illness. Retrospective and prospective methods have been the primary way to measure premorbid social functioning. Despite strengths of each approach, several confounds of both designs may limit interpretations of results. The high-risk longitudinal prospective method was developed to address some of the aforementioned methodological limitations. The current study investigates premorbid social functioning in a Danish schizophrenia high-risk longitudinal cohort. Participants were assessed at ages 10-13 years, prior to their development of a psychiatric disorder, through the use of multiple informants including the children themselves, parents, and teachers. Participants were then followed up with a clinical interview as adults. Adult diagnostic outcome was divided into three groups: schizophrenia-spectrum disorder, non-schizophrenia spectrum psychiatric disorder, and no mental illness. Results indicate that all informants reported significant differences in premorbid social functioning between participants who developed a schizophrenia-spectrum disorder and no mental illness. Teachers were found to be able to differentiate premorbid social functioning between participants who later developed a schizophrenia-spectrum disorder and a non-spectrum psychiatric disorder in addition to no mental illness, suggesting the potential importance of teacher ratings of premorbid social functioning as it pertains to adult schizophrenia-spectrum outcome