A meta-analysis of neuropsychological functioning in patients with early onset schizophrenia and pediatric bipolar disorder.

Despite the nosological distinction between bipolar disorder and schizophrenia, there is increasing evidence that these conditions share phenomenological characteristics. To examine the similarities in their patterns of cognitive impairment, we conducted a meta-analysis from 12 studies of Early Onset Schizophrenia (EOS) and 12 studies of Pediatric Bipolar Disorder (PBD). We found that individuals with PBD suffer from cognitive deficits (e.g., verbal learning and memory, processing speed, or executive control) that are milder but similar in nature to those of patients with EOS. Qualitative similarities between the neuropsychological profiles produced by these groups of patients might represent a "continuum of psychosis" or reflect some degree of genetic biological overlap.