Timing of puberty and syndromes of schizotypy: a replication

Abstract

The view of schizophrenia as a neurodevelopmental disorder involving an abnormality in the programmed elimination of excitatory synapses during puberty has been supported by recent neuroimaging studies suggesting disordered functional connectivity in schizophrenia. We investigated a model predicting dysfunctionally high or low synaptic density in extreme early or late maturers at puberty, respectively (Saugstad, L.F., 1989. Clin. Genet. 36, 156–167; Saugstad, L.F., 1994. Int. J. Psychophysiol. 18, 189–203). In an earlier study (Gruzelier, J.H., Kaiser, J., 1996. Schizophr. Res. 21, 183–194), we found increased psychosis proneness scores in both extremes of the pubertal timing spectrum in the normal population. Here we present a replication study where N=100 healthy adults completed a retrospective pubertal timing scale and the ‘Personality Syndrome Questionnaire’ measuring schizotypy syndromes. The following relationships were replicated: (1) elevated scores on scales of the total Unreality syndrome and the Ideas of Reference subscale in both maturation extremes; and (2) a trend for a positive correlation between the Withdrawal scale and the composite maturation score in males. Cognitive Unreality and Suspiciousness were higher in early than late maturing females. Social Anxiety was elevated in female extreme maturers compared with average maturers, but the opposite was found for males, where average maturers had higher scores than early or late maturers. Active syndrome findings were confined to the male subsample with late maturing males showing higher scores on the Cognitive Failures and Odd Speech subscales than early maturers. As in the previous study, there was no relationship between a global psychosis proneness scale and maturational rate. These findings support a neurodevelopmental model of psychosis-proneness and show the importance of adopting a syndromal view.