Neurocognition and its association with adverse childhood experiences and familial risk of mental illness

Background: Neurocognitive deficits are considered an endophenotype for several psychiatric disorders, typically studied in unaffected first-degree relatives (FDRs). Environmental factors such as adverse childhood experiences (ACEs) may also affect neurocognition. This study examines the effect of ACEs on neurocognitive performance in FDRs of patients with severe mental illness in order to determine whether familial risk has a moderating effect on the relationship between ACEs and neurocognition. Methods: The sample consists of a total of 512 individuals composed of unaffected FDRs from multiplex families with severe mental illnesses (schizophrenia, bipolar disorder, obsessive-compulsive disorder or alcohol use disorder) and healthy controls (with no familial risk). Neurocognitive tests included processing speed (Color Trails), new learning (Auditory Verbal Learning Test), working memory (N-Back), and Theory of Mind (SOCRATIS). ACEs were measured using the WHO ACE-International Questionnaire (ACE-IQ). Regression models adjusted for age, gender and education were done to predict each neurocognitive domain by the effect of familial risk, ACE-IQ Total Score and the interaction (familial risk x ACE-IQ Total score). Results: When all FDRs were examined as a group, the main effect of familial risk predicted poor performance in all domains of neurocognition (p <0.01), and the ACEs x familial risk interaction had a significant negative association with global neurocognition, processing speed & working memory. This interaction effect was driven predominantly by the familial risk of AUD. In FDRs of schizophrenia & bipolar disorder, only the main effects of familial risk were significant (working memory, theory of mind & global neurocognition), with no impact of ACEs or its interaction in both these sub-groups. Conclusions: The impact of childhood adversity on neurocognition is moderated by familial risk of psychiatric disorders. Genetic or familial vulnerability may play a greater role in disorders such as schizophrenia and bipolar disorder, while the interaction between ACEs and family history may be more relevant in the case of disorders with greater environmental risk, such as substance use.