Psychiatrist, Nova Scotia Health Authority; Department of Pathology; Department of Psychology and Neuroscience; Department of Medical Neuroscience; Department of Psychiatry, Dalhousie University; IWK Health Centre, Canada; and Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK
BackgroundBasic symptoms, defined as subjectively perceived disturbances in thought, perception and other essential mental processes, have been established as a predictor of psychotic disorders. However, the relationship between basic symptoms and family history of a transdiagnostic range of severe mental illness, including major depressive disorder, bipolar disorder and schizophrenia, has not been examined.AimsWe sought to test whether non-severe mood disorders and severe mood and psychotic disorders in parents is associated with increased basic symptoms in their biological offspring.MethodWe measured basic symptoms using the Schizophrenia Proneness Instrument – Child and Youth Version in 332 youth aged 8–26 years, including 93 offspring of control parents, 92 offspring of a parent with non-severe mood disorders, and 147 offspring of a parent with severe mood and psychotic disorders. We tested the relationships between parent mental illness and offspring basic symptoms in mixed-effects linear regression models.ResultsOffspring of a parent with severe mood and psychotic disorders (B = 0.69, 95% CI 0.22–1.16, P = 0.004) or illness with psychotic features (B = 0.68, 95% CI 0.09–1.27, P = 0.023) had significantly higher basic symptom scores than control offspring. Offspring of a parent with non-severe mood disorders reported intermediate levels of basic symptoms, that did not significantly differ from control offspring.ConclusionsBasic symptoms during childhood are a marker of familial risk of psychopathology that is related to severity and is not specific to psychotic illness.Declaration of interestNone.