In the July issue of the American Journal of Psychiatry Ian Kelleher from Dublin and colleagues from an international research consortium report on the relationship between traumatic childhood experiences and the occurrence of psychotic symptoms (Kelleher et al., Am J Psychiatry 2013; 170: 734-741).The study is part of a large EU-funded study on suicide prevention in adolescents (Saving and Empowering Young Lives in Europe, SEYLE) conducted in 11 countries. From Germany, the Department of Child and Adolescent Psychiatry at the University of Heidelberg is involved in SELYE. The authors examined a representative sample of young people aged 13-16 years in Irish schools.
1112 adolescents, 92% of them 13 to 14 years of age, 45% female, were enrolled. At the baseline examination, the adolescents were interviewed for the experience of (physical) violence and bullying, respectively, using standardized questionnaires. After three and then again after 12 months, a follow-up examination took place. Physical violence was captured by the following question: “Have you, during the past 12 months, been physically attacked?”. In a second question they were asked who carried out the assault (parent, other relative, schoolmate, other acquaintance, unknown individual). The experience of bullying was assessed by six questions: “In the past 12 months, have others often spread rumors about you? Teased you? Deliberately left you out of activities? Taken money, property, or food from you? Called you names? Made fun of how you look or talk?” From these six yes/no questions, a score from 0 to 6 was created. Psychotic experiences were recorded with the following question: “Have you ever heard voices or sounds that no one else can hear?”.
At baseline, 7% (n = 77) of the participants reported on psychotic symptoms. 10% reported the experience of physical violence over the past 12 months (45% by a schoolmate, 16% by a family member, 14% by acquaintances and 37% by an unknown individual, some young people were attacked by more than one person, so that the percentages add up to more than 100%). 39% of the participants (n = 409) had been victims of bullying at the baseline examination during the preceding 12 months .
Both the experience of physical violence and bullying clearly increased the risk for psychotic symptoms at one of the two follow-up investigations. 9.5% of the victims of bullying reported on psychotic symptoms after three months and 6.9% after 12 months. This corresponds to a 4.4 – and 3.4-fold increase in risk. Even more pronounced were the effects of physical violence: 13.3% of the victims of violence reported on psychotic symptoms after three months and 12.9% after 12 months. Thus, the risk was increased 4.8 – and 6.2-fold.
With the severity of bullying the risk of psychotic symptoms increased significantly: the adolescents who had only one “yes” response in the baseline examination, had a 3.5-fold increased risk of experiencing psychotic symptoms already at that time point. After three and 12 months it was 1.5 – and 3.8-fold increased. Subjects with a score of “3” or higher at baseline had a 9.5-fold increased risk at baseline, and it was increased 5-fold and 7.9-fold after three and 12 months, respectively.
Perhaps even more important is the observation that the risk for psychotic symptoms decreased with the cessation of bullying. In adolescents who had indicated to be bullied at the baseline examination, but who no longer reported this after three and 12 months, the risk for psychotic symptoms was reduced by 60-70% compared to adolescents who were continuously exposed to bullying.
Conversely, experiencing psychotic symptoms at the baseline examination predicted the experience of physical violence or bullying to the two follow-up time points. The risk was increased by the 5 – to 12-fold.
This important study shows a bidirectional relationship between traumatic childhood experiences and psychotic symptoms. It suggests that preventive measures that lead to the reduction of abuse at home or bullying at school, could also lead to a reduction in the frequency of severe mental disorders such as psychosis.
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