Johan Isaksson, PhD, and colleagues at Uppsala University, Sweden, abstracted data from a community-based prospective cohort of young adolescents born in 1997 and 1999 in the Swedish county of Västmanland. During wave 1 (2012) and wave 2 (2015) of the study, participants completed a self-report questionnaire by regular mail. The questionnaire captured sociodemographic characteristics, past-year PLEs, and internalizing (depression; anxiety) and externalizing (attention-deficit/hyperactivity disorder; conduct problems) symptoms. Hierarchical binary logistic regression models were used to assess the predictive validity of PLEs for psychiatric symptoms.
In the sample (n=1445; mean age, 14.38±1.04 years; 57.8% girls), more than a third (37.6%) of adolescents reported at least 1 PLE at either assessment, and 17.1% reported 4 or more. At wave 1, 18.4% and 27.8% of patients were categorized as having internalizing and externalizing symptoms, respectively; at wave 2, these numbers increased to 33.4% and 37%, respectively.
Per hierarchical modeling, PLEs at wave 1 were significantly associated with internalizing symptoms at wave 2 (odds ratio [OR], 1.09; 95% CI, 1.04-1.15; P =.001) after adjustments for age, sex, race/ethnicity, socioeconomic status, and baseline psychiatric symptoms. Internalizing symptoms at wave 2 were also significantly associated with internalizing symptoms at baseline (P <.001), externalizing symptoms at baseline (P =.025), female sex (P <.001), and non-Scandinavian ethnicity (P =.019).
The relationship between internalizing symptoms and PLEs was similar for probable depression (OR, 1.08; 95% CI, 1.03-1.14; P =.003) and anxiety disorder (OR, 1.11; 95% CI, 1.05-1.17; P <.001).
In addition, PLEs at baseline were nominally, although not significantly, associated with externalizing symptoms at wave 2 (OR, 1.04; 95% CI, 0.99-1.10; not significant). Instead, externalizing symptoms at wave 2 were predicted by internalizing symptoms at baseline (P =.044), externalizing symptoms at baseline (P <.001), and older age (P =.020). In post hoc analyses, PLEs were found to predict conduct problems, but not attention-deficit/hyperactivity disorder, 3 years later (OR, 1.08; 95% CI, 1.02-1.14; P =.012).
As study limitations, investigators cited the reliability issues associated with self-report, the lack of data available for mental health interventions, and the homogenous nature of the study cohort.
The investigators described PLEs as a potential “marker for psychiatric symptoms and as a putative antecedent for future psychopathology.” They further emphasized the importance of assessing PLEs in the stage of early adolescence.
Isaksson J, Vadlin S, Olofsdotter S, Åslund C, Nilsson KW. Psychotic-like experiences during early adolescence predict symptoms of depression, anxiety, and conduct problems three years later: a community-based study [published online October 30, 2019]. Schizophr Res. doi:10.1016/j.schres.2019.10.033