Baseline grey matter volume of non-transitioned “ultra high risk” for psychosis individuals with and without attenuated psychotic symptoms at long-term follow-up

• Published in: Schizophrenia research 2016-06, Vol.173 (3), p.152-158
• Main Authors: Cropley, Vanessa L, Lin, Ashleigh, Nelson, Barnaby, Reniers, Renate L.E.P, Yung, Alison R, Bartholomeusz, Cali F, Klauser, Paul, Velakoulis, Dennis, McGorry, Patrick, Wood, Stephen J, Pantelis, Christos
• Format: Article
• Language: English
• Subjects: Attenuated psychotic symptoms; Cerebral Cortex - diagnostic imaging; Female; Follow-Up Studies; Gray Matter - diagnostic imaging; Grey matter volume; Humans; Imaging; Magnetic Resonance Imaging; Male; Non-transition; Organ Size; Psychiatric Status Rating Scales; Psychiatry; Psychosis; Psychotic Disorders - diagnostic imaging; Psychotic Disorders - psychology; Risk; Ultra-high risk; Young Adult
• ISSN: 0920-9964; 1573-2509
• DOI: 10.1016/j.schres.2015.05.014

Abstract Introduction Two thirds of individuals identified as ultra-high risk (UHR) for psychosis do not transition to psychosis over the medium to long-term (non-transition; UHR-NT). Nevertheless, many of these individuals have persistent attenuated psychotic symptoms (APS). The current study examined whether there were differences in baseline grey matter volume (i.e. at initial identification as UHR) in UHR-NT individuals whom had APS compared to those without APS (No-APS) at medium to long-term follow-up. Methods Participants were help-seeking individuals who were identified as being at UHR for psychosis between 2 and 12 years previously (mean = 7.5). The sample consisted of 109 participants who underwent a Magnetic Resonance Imaging scan at baseline and who had not been observed to develop a psychotic disorder over the follow-up period (UHR-NT). Using voxel-based morphometry, baseline grey matter volume (GMV) was compared between participants with (N = 30) and without (N = 79) APS at follow-up. Results At baseline, the APS and No-APS groups were clinically indistinguishable. At follow-up, the APS group had significantly worse symptoms and impaired functioning. Individuals with APS had reduced baseline GMV in frontal, temporal, posterior and cingulate regions compared to those without APS at follow-up. Reduced GMV was associated with more severe positive, negative and depressive symptoms and lower global functioning in the combined UHR-NT cohort. These associations were independent of later APS outcome. Discussion This study found that differences in regional GMV are discernible at an early stage of UHR and may be specific to individuals who have APS and psychopathology at follow-up. Our findings suggest that lower GMV at baseline may confer neurobiological risk for later APS and/or increased psychopathology while the absence of these structural abnormalities might be protective.