Early trauma and familial risk in the development of the extended psychosis phenotype in adolescence
Mild psychotic experiences, such as occasionally hearing voices or having mild feelings of paranoia, are common in young people. For most adolescents, such experiences are transitory in nature and do not necessarily develop into clinical psychotic disorder. For a minority of adolescents, however, such experiences may be predictive of later psychiatric problems. A recent study by Hanneke Wigman (Utrecht and Maastricht Universities) investigated the development of mild psychotic experiences in the TRAILS study. They found that there exists a small subgroup of adolescents that, although generally sill attending school and functioning well, reports persistent levels of mild psychotic experiences. The experience of trauma, such as being bullied or being exposed to violence, predicted persistence of such experiences over time. Also, it was shown that children whose parents reported psychotic pathology in their past had an almost four times higher chance of reporting persistent mild psychotic experiences over time. No interaction between these two factors was found, possibly due to limited statistical power. This study shows that even at the level of the general population (i.e. long before clinical psychotic symptoms arise), a small subgroup of adolescents can be identified that reports persisting mild psychotic experiences and that both familial and environmental factors impact on this persistence. This may offer possibilities for the development of (very) early intervention, that potentially may delay or even prevent such mild psychotic experiences from developing into clinical disorders.