M63. TRANSDIAGNOSTIC NEUROCOGNITIVE DEFICITS IN PSYCHIATRY: A REVIEW OF META-ANALYSES

BACKGROUND: In recent decades, several meta-analyses have documented the severity of neurocognitive impairments in various domains and psychiatric disorders. There is also a growing body of literature on the common factors among psychiatric disorders (e.g., common psychological factors, neurobiological alterations or genetic variants). The first objective of this review was to investigate transdiagnostic neurocognitive impairments across several psychiatric disorders. The second objective was to document transdiagnostic neurocognitive impairments across the life span, to establish whether they are consistent across age. METHODS: A literature search was conducted in Pubmed, PsycINFO and Embase to identify all meta-analyses of neurocognitive deficits in psychiatry published prior to August, 2017. The following psychiatric disorders were considered: mood disorders, psychotic disorders, autism spectrum disorders, attention-deficit/hyperactivity disorder (ADHD), and anxiety disorders. The R-AMSTAR (Revised Assessment of Multiple Systematic Reviews) was used to assess methodological quality of all retrieved meta-analyses. The final selection included only the most rigorous meta-analyses. RESULTS: A total of 36 meta-analyses were included. They documented neurocognitive impairments in schizophrenia, autism spectrum disorder, ADHD, bipolar disorder, depression, obsessive-compulsive disorder, and posttraumatic stress disorder. Neurocognitive impairments were observed in the majority of psychiatric disorders, regardless of age group (childhood/adolescence, first episode, adulthood, elderly). Across all disorders, deficits in executive functions and in episodic memory were the most severe and the most frequently reported. Moreover, severe deficits in executive functions were frequently reported across age groups. Neurocognitive deficits were consistently more severe in schizophrenia compared to other psychiatric disorders, across all age groups. DISCUSSION: Neurocognitive impairments were observed in almost all disorders, in all age groups. Some neurocognitive impairments were more frequently reported across all disorders. Indeed, executive functions and episodic memory were severely impaired in almost every age group and psychiatric disorder considered in this review. Deficits in these two domains appear to be transdiagnostic and they remain relatively stable across the life span. Transdiagnostic factors could be key targets for transdiagnostic cognitive interventions in psychiatric populations. Neurobiological, neuropsychological, and genetic hypotheses of transdiagnostic neurocognitive impairments are discussed.