Latent Class Analysis of ADHD Neurodevelopmental and Mental Health Comorbidities

Objective: Many children diagnosed with attention-deficit/hyperactivity disorder (ADHD) experience co-occurring neurodevelopmental and psychiatric disorders, and those who do often exhibit higher levels of impairment than children with ADHD alone. This study provides a latent class analysis (LCA) approach to categorizing children with ADHD into comorbidity groups, evaluating condition expression and treatment patterns in each group.

Methods: Parent-reported data from a large probability-based national sample of children diagnosed with ADHD (2014 National Survey of the Diagnosis and Treatment of ADHD and Tourette Syndrome) were used for an LCA to identify groups of children with similar groupings of neurodevelopmental and psychiatric comorbidities among children with current ADHD (n = 2495). Differences between classes were compared using multivariate logistic regressions.

Results: LCA placed children who were indicated to have ADHD into 4 classes: (low comorbidity [LCM] [64.5%], predominantly developmental disorders [PDD] [13.7%], predominantly internalizing disorders [PID] [18.5%], and high comorbidity [HCM] [3.3%]). Children belonging to the HCM class were most likely to have a combined ADHD subtype and the highest number of impaired domains. Children belonging to the PDD class were most likely to be receiving school services, whereas children in the PID class were more likely to be taking medication than those belonging to the LCM class who were least likely to receive psychosocial treatments.

Conclusion: Latent classes based on co-occurring psychiatric conditions predicted use of varied treatments. These findings contribute to the characterization of the ADHD phenotype and may help clinicians identify how services could be best organized and coordinated in treating ADHD.