Multiple Network Dysconnectivity in Adolescents with Psychotic Experiences: a longitudinal population-based study

Functional dysconnectivity amongst neural networks is well established in
psychosis, and has been implicated in the psychopathology associated with the disorder. However,
little is known about functional connectivity (FC) in individuals, particularly adolescents, who
experience sub-threshold psychotic experiences (PE), and their trajectory over time. Thus, the aim of
this study was to investigate large and small-scale network FC in adolescents with PE.

A population-based case-control study of 24 adolescents (mean age 13.58) who met
criteria for PE were drawn from a sample of 211 young people recruited for a neuroimaging study,
followed up 2 years later (n=18, mean age = 15.78), and compared to matched controls drawn from
the same sample. Functional seed networks included the default mode (DMN), salience (SN), central
executive (CEN), motor (MN), and auditory networks (AN). Whole-brain FC analyses were performed
using the CONN functional connectivity toolbox.

At both timepoints, the PE group generally displayed significant hypoconnectivity,
with specific instances of hyperconnectivity, compared to controls. At baseline, FC in the PE group
was decreased between regions in the MN and DMN, and the AN and visual regions. At follow up, FC
in the PE group was decreased between regions in the SN and DMN, the AN and visual regions, and
also within the MN.

Significant hypoconnectivity across multiple networks reflects findings in
established psychosis, supporting a prominent role for the default mode network in the
dysfunctional information processing and integration thought to underlie psychotic experiences.