JOINT MULTI-FAMILY HISTORY AND MULTI-POLYGENIC SCORE PREDICTION OF MAJOR DEPRESSIVE DISORDER

Major depressive disorder (MDD) is a complex psychiatric disorder influenced by genetic, social, and environmental factors. Family history and polygenic risk scores of MDD and related psychiatric disorders are strong predictors for MDD, while childhood trauma (CT) also plays a crucial role. This study aimed to jointly model the predictive effect of multi-family history (mFH), multi-PRS (mPRS), and childhood trauma on the development of MDD and the number of MDD episodes experienced. Our aim was to identify predictive model useful for stratification to more or less intensive treatment plans and interventions.

Data were obtained from the NIHR BioResource Genetic Links to Anxiety and Depression (GLAD) study and UK Biobank (UKB). MDD diagnosis followed DSM-V criteria using the same online mental health questionnaire data in GLAD and UKB. Family history (Yes/No) was reported for up to 22 psychiatric disorders. MegaPRS was used to calculate PRSs based on large genome-wide association studies. Reported childhood trauma was identified via the5-item childhood trauma screener questionnaire. Elastic net regression with nested cross-validation was applied.

In GLAD (9,927 MDD cases, 4,452 controls), mFH explained 16.85% of MDD variance, followed by CT (10.62%), demographics (9.92%), and mPRS (7.73%). All predictors together explained 33.87% of MDD variance, with corresponding areas under the receiver operating characteristic curve (AUC) of 0.84 and a positive predictive value (PPV) of 0.81. In UKB (40,667 MDD cases, 70,755 controls), mFH explained 13.56% of MDD variance, followed by demographics (5.95%), CT (5.87%), and mPRS (3.69%). Together, all predictors explained 23.68% of variance (AUC=0.74, PPV=0.66). The strongest individual predictor in both cohorts is family history of depression, followed by CT, sex, family history of anxiety, and PRS for depression. The modal number of MDD episodes among MDD cases is ≥ 13 episodes in GLAD, compared to 1 episode in UKB. Additionally, the mean age of onset is 21 years in GLAD and 33 years in UKB. When the model was applied to other MDD phenotypes, all predictors accounted for 25.80% of the variances for the number of MDD episodes and 8.41% for age of onset in GLAD, and 11.92% and 6.01% in UKB, respectively.

Integrating multi-family history, multi-PRS, childhood trauma, and demographics enhances MDD prediction. The prediction model performs effectively in both severe MDD cohort (GLAD) and population-based cohort (UKB), suggesting its potential generalizability to broader populations. The strongest predictors are family history of depression and childhood trauma, both of which are easily measurable in clinical settings. Furthermore, the model trained for MDD prediction also proves to be a strong predictor for the number of MDD episodes and age of onset, indicating its effectiveness in predicting the severity of MDD.