Pituitary volume predicts future transition to psychosis in individuals at ultra-high risk of developing psychosis.
BACKGROUND
We examined pituitary volume before the onset of psychosis in subjects who were at ultra-high risk (UHR) for developing psychosis.


METHODS
Pituitary volume was measured on 1.5-mm, coronal, 1.5-T magnetic resonance images in 94 UHR subjects recruited from admissions to the Personal Assessment and Crisis Evaluation Clinic in Melbourne, Australia and in 49 healthy control subjects. The UHR subjects were scanned at baseline and were followed clinically for a minimum of 1 year to detect transition to psychosis.


RESULTS
Within the UHR group, a larger baseline pituitary volume was a significant predictor of future transition to psychosis. The UHR subjects who later went on to develop psychosis (UHR-P, n = 31) had a significantly larger (+12%; p = .001) baseline pituitary volume compared with UHR subjects who did not go on to develop psychosis (UHR-NP, n = 63). The survival analysis conducted by Cox regression showed that the risk of developing psychosis during the follow-up increased by 20% for every 10% increase in baseline pituitary volume (p = .002). Baseline pituitary volume of the UHR-NP subjects was smaller not only compared with UHR-P (as described above) but also compared with control subjects (-6%; p = .032).


CONCLUSIONS
The phase before the onset of psychosis is associated with a larger pituitary volume, suggesting activation of the HPA axis.
Garner
Belinda
B
Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Royal Melbourne Hospital, Melbourne, Australia.
Pariante
Carmine M
CM
Wood
Stephen J
SJ
Velakoulis
Dennis
D
Phillips
Lisa
L
Soulsby
Bridget
B
Brewer
Warrick J
WJ
Smith
Deidre J
DJ
Dazzan
Paola
P
Berger
Gregor E
GE
Yung
Alison R
AR
van den Buuse
Maarten
M
Murray
Robin
R
McGorry
Patrick D
PD
Pantelis
Christos
C
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D010902:Pituitary Gland / Q000473:pathology*; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000473:pathology*; D012306:Risk; D012565:Schizophrenic Psychology; D015996:Survival Rate; D013997:Time Factors