Link between psychiatric symptoms and cognition

Researchers have found both positive and negative associations between mental symptom severity and general cognition. Prior studies showed mixed findings. But this study, by noting that the associations were nonlinear, reconciled those prior studies, which assumed that symptom severity tracked with cognitive ability. In fact, the association between cognition and symptoms may be the opposite in low vs. high symptom severity samples. The study shows that it's necessary to use clinical information in studies of cognitive impairment. Because mental illnesses are a leading cause of disability, and cognitive impairments often play a role across psychiatric disorders. The researchers wanted to determine if the association between general cognition and mental health symptoms diverges at different symptom severities in children. For the study, researchers used the ongoing Adolescent Brain and Cognitive Development (ABCD) study to assess 5175 children at ages 9 to 11 years. They evaluated aggregate cognitive test scores (general cognition) in relation to total and subscale-specific symptoms reported from the Child Behavioral Checklist. Linear models showed differing associations between general cognition and mental health symptoms, depending on the range of symptom severities queried. Nonlinear models confirm that internalizing symptoms were significantly positively associated with cognition at low symptom burdens and significantly negatively associated with cognition at more severe symptoms. [Pines, A., Tozzi, L., Bertrand, C., et al. (2024, Dec). Psychiatric symptoms, cognition, and symptom severity in children. JAMA Psychiatry, 81(12), 1236–1245. https://doi.org/10.1001/jamapsychiatry.2024.2399.]