Assessing a prediction model for depression risk using an early adolescent sample with self‐reported depression

Abstract Background Major depressive disorder (MDD) in adolescence is a risk factor for poor physical and psychiatric outcomes in adulthood, with earlier age of onset associated with poorer outcomes. Identifying Depression Early in Adolescence Risk Score (IDEA‐RS) is a model for predicting MDD in youth aged >15 years, but replication in younger samples (<15 years) is lacking. Here, we tested IDEA‐RS in a younger sample (9–11 years) to assess whether IDEA‐RS could be applied to earlier onset depression. Methods We applied IDEA‐RS predictor weights to 9854 adolescents (9–11 years) from the Adolescent Brain Cognitive Development (ABCD) Study, United States. We derived incident depression outcomes from self‐reported data at 2‐year follow‐up (11–13 years): incident MDD and increase in depression symptoms (DS). Sensitivity analyses were conducted using parent‐reported data. We assessed accuracy and calibration in predicting self‐reported incident depression and compared this to a refitted model with predictor weights derived in ABCD. Lastly, we tested associations between IDEA‐RS predictors and self‐reported incident depression. Results External replication yielded better‐than‐chance discriminative capacity for self‐reported incident depression (MDD: AUC = 61.4%, 95% CI = 53.5%–69.4%; DS: AUC = 57.9%, 95% CI = 54.6%–61.3%) but showed poor calibration with overly extreme risk estimates. Re‐estimating predictor weights improved discriminative capacity (MDD: AUC = 75.9%, 95% CI = 70.3%–81.4%; DS: AUC = 64.8%, 95% CI = 61.9%–67.7%) and calibration. IDEA‐RS predictors ‘poorest level of relationship with the primary caregiver’ (OR = 4.25, 95% CI = 1.73–10.41) and ‘high/highest levels of family conflict’ (OR = 3.36 95% CI = 1.34–8.43 and OR = 3.76 95% CI = 1.50–9.38, respectively) showed greatest associations with self‐reported incident MDD. Conclusions While IDEA‐RS yields better‐than‐chance predictions on external replication, accuracy is improved when differences between samples, such as case‐control mix, are adjusted for. IDEA‐RS may be more suited to research settings with sufficient data for refitting. Altogether, we find that IDEA‐RS can be generalisable to early adolescents after refitting and that family dysfunction may be especially impactful for this period of development.