The Need for Research on Intellectual Disabilities and Severe Psychiatric Disorders in Children and Adolescents

The co-existence of intellectual disability (ID) and psychiatric disorders is fairly common throughout the lifespan, but there is only limited research on children, adolescents, and young adults with ID and co-occurring, severe psychiatric disorders. Children and adolescents with ID or very low Full Scale IQs are often excluded from studies of psychopathology, including many that investigate Schizophrenia, Psychosis Not Otherwise Specified, other psychotic disorders, Posttraumatic Stress Disorder, Bipolar Disorder, Major Depressive Disorder, and other mood disorders. As a result, the co-occurrence of ID and many disorders in childhood and adolescence is not well understood. In spite of current knowledge about the impact of both childhood maltreatment and psychotic disorders on cognitive development, there are also relatively few studies that explore specific cognitive deficits in youth with ID and psychosis, and few that investigate trauma variables in youth with ID and severe psychiatric disorders. At present, there is similarly little research on the implementation of evidenced supported treatment with dually diagnosed children and adolescents with ID who experience severe psychopathology. This article outlines the importance of further research on the interaction between ID, cognitive impairments, psychotic disorders, mood disorders, and PTSD as a necessary condition for informing and guiding the treatment of children, adolescents, and young adults with co-occurring ID and severe psychiatric disorders. on specific cognitive deficits associated with ID and severe disorders suggests that individuals with ID have neuropsychological impairments, such as in verbal memory, communication skills, and executive functioning [10]. Our twofold goal is to very briefly summarize current knowledge about ID, severe disorders, and cognition in children and youth, and to emphasize the need for research on co-occurring ID and psychopathology that emphasizes cognitive deficits and trauma variables. The Need for Research on ID and Cognitive Deficits in Children and Adolescents Even though low IQs are inevitably linked with cognitive deficits, there is considerable variability among individuals with and without psychiatric disorders. Children with ID generally have worse phonological functioning, sensory motor skills and working memory than youth with higher IQs [11]. Heterogeneous cognitive deficits are also commonplace in adolescents with ID, including verbal memory, working memory, and executive functioning impairments [12]. Deficits in verbal memory, comprehension, and executive functioning are similarly common in adults with ID [13]. Among adults with SC, ID is associated with marked problems in executive functioning as well as cognitive inhibition deficits [14]. Children and adolescents with psychotic disorders often experiences cognitive deterioration in