Young people with psychotic spectrum (PS) disorders exhibit significant differences in brain structure, compared to youth without these disorders, according to a new study published in the Journal of the American Academy of Child and Adolescent Psychiatry.
PS disorders, which include schizophrenia, schizoaffective disorder, delusional disorder and schizotypal personality disorder, are characterized by abnormalities in beliefs, perceptions and behavior; but how these disorders manifest in the early stages is largely unknown.
“Psychosis is viewed as a psychiatric disorder that arises from neurodevelopmental alterations. However, until recently, the focus of neuroimaging studies has been on adults who have already developed a psychotic disorder,” said lead author Maria Jalbrzikowski, Ph.D., assistant professor in the Department of Psychiatry at the University of Pittsburgh School of Medicine.
“With access to large, publicly available datasets such as the Philadelphia Neurodevelopmental Cohort, we can really start to investigate how alterations in neurodevelopment contribute to the development of psychotic symptoms.”
Specifically, the researchers found surface area reductions in a number of cortical brain regions in comparison to typically developing youth; youth with bipolar spectrum disorders; and youth with both psychosis and bipolar spectrum disorders. The brain regions involved are vital for everyday functioning and cognitive skills.
The findings are based on the structural neuroimaging analyses conducted on participants from the Philadelphia Neurodevelopmental Cohort (PNC), a population-based sample of 10,000 youth (ages 9 to 22) in the Philadelphia metro area.
Structural magnetic resonance neuroimaging (MRI) data were collected on a subset of the group, followed by measuring the cortical thickness. Study participants were also evaluated for psychiatric symptoms using a structured interview and the following groups were created: typically developing (376); psychosis spectrum (113); bipolar spectrum (117); and PS + bipolar spectrum (109).
Compared with all other groups, PS youth exhibited significantly decreased surface area in the orbitofrontal, cingulate, precentral, and postcentral regions. PS youth also showed decreased thalamic volume compared with all other groups. The brain alterations were restricted to youth with only PS symptoms, not those who exhibited both psychosis spectrum and bipolar spectrum symptoms.
“This suggests that those who have both types of symptoms (psychosis and bipolar spectrum) may have different underlying neural mechanisms that contribute to symptoms, in comparison to those with psychotic spectrum symptoms only,” said Jalbrzikowski.