Cumulative risk for comorbidity of depression and anxiety in young people

Depression and anxiety often co-occur, resulting in a more severe prognosis than either condition alone. Identifying the impact of risk factors on this comorbidity is essential for guiding early interventions.

Data from 4563 young participants in the Growing Up in New Zealand (GUiNZ) longitudinal study were analysed to identify risk factors associated with comorbid depression and anxiety. Scores for depression and anxiety symptoms were converted into binary variables using the cut-off of 10 and 60, respectively, and then combined to create the comorbidity outcome. A Cumulative Risk (CR) score was used to measure the impact of multiple risk factors from prenatal to childhood on the likelihood of this comorbidity. CR scores were further grouped into three levels of risk, and their association with comorbidity was examined using univariable and multivariable logistic regression analyses.

The prevalence of comorbidity at age 12 years was 8.9% (406/4563). Among young people, 14.2% (647/ 4563) had no risk factors, 64.7% (2953/4563) had one to three (low CR score level), and 21.1% (963/4563) had four or more risk factors (high CR score level). In the adjusted analyses, young people in the low and high CR levels had 2.6 times and 4.6 times higher odds, respectively, of experiencing comorbidity compared to those with no risk factors.

The risk of comorbid depression and anxiety symptoms increases with the number of risk factors experienced from prenatal to childhood. Multi-faceted interventions targeting several risk factors are recommended to improve youth mental health.