Oades, R. D., (2001). Early onset schizophrenia, risk and the selective aspect of perception. World Journal of Biological Psychiatry, 2, 98..

Most risk factors are not specific for early-onset schizophrenia (EOS), but the illness may show a distinct pattern of development for interrelated features.

In the Essen adolescent cohort (4) (53 subjects followed up 15y after mean onset at 15y-of-age) non-specific features included complications at birth, cluster A personality disorders in close relatives, and social isolation and solitary play on 6-12 year-olds. Other typical EOS characters included a poor premorbid social adjustment, gradual and insidious onset, male gender and predominant negative symptoms.

Although a separate cohort of 44 subjects with a mean onset at 13y did not show a predominant male gender or gradual onset, a subgroup with psychosis onset in childhood (< 11y) were largely male with a gradual begin to the illness. An analysis of their premorbid features gave 4 dimensions that reflect aspects of their "isolation" (1).

It is proposed to model poor premorbid selective perceptual processes with the psychophysiological measure of deviance detection / mismatch negativity, MMN, (outside world) with poor integration in the internal world (iterative frontal-temporal lobe dialogue). MMN is reduced in adolescent schizophrenia (2): here, frontal and temporal lobe MMN dipole sources are described along with the first evidence of a shift in early-onset patients (3) .

Early abnormalities in these attention-related processes may underlie the poor development of adaptive social responses and have their origins in the early developmental history and family environment of EOS patients.

1. Eggers C, & Bunk D, (1997). The long-term course of childhood-onset schizophrenia: a 42-year follow-up. Schizophr. Bull., 23, 105-117.
2. Oades RD, et al., (1997). Impaired attention-dependent augmentation of MMN in nonparanoid vs. paranoid schizophrenic patients: a comparison with obsessive.compulsive disorder and healthy subjects Biol. Psychiat., 41, 1196-1210.
3. Oades RD, et al., (2001). Sources of prefrontal activity for auditory working memory (MMN): evidence for an impaired fronto-temporal lobe dialogue in schizophrenia. Eighth International Congress: Schizophrenia Research, [Latebreaking data], Whistler, B.C., Canada
4. Röpcke B, Oades RD, & Eggers C, (2000). Predictors for the 15-year outcome of schizophrenia with an early-onset in adolescence. Schizophr. Res., 41, 79.