Substance use diagnoses among patients who present to federally run mental health facilities with co-morbid ADHD and bipolar disorder between 2013-2023: a national analysis using random forest methods

Background/Objectives Although substance use disorder is common in patients with attention deficit hyperactivity disorder or bipolar disorder, limited recent data exist for those with these co-occurring conditions. Our study analyzes recent trends and predictors of these diagnoses.Methods We conducted a secondary analysis of 2013–2023 Mental Health Client-Level Data, identifying patients with co-morbid ADHD and bipolar disorder and their SUD prevalence. Joinpoint regression was used to analyze trends, and random forest models identified the most important predictors.Results Between 2013 and 2023, 5,691 patients (0.008%) had comorbid ADHD and bipolar disorder, with rates increasing by 0.01% per year starting in 2016 (p < 0.0001). All patients had a documented SUD. Most patients were White (75.7%) and unemployed (1,284; 22.6%). The most common SUD diagnoses were 1) other unspecified substance dependence (665, 11.7%), 2) alcohol dependence (474, 8.3%), and 3) cannabis dependence (450, 7.9%). Key predictors included age, education, employment, and marital status.Conclusions Our study identified the most common types of SUDs among those with co-morbid ADHD and bipolar disorder and associated risk factors. This will guide prevention and early intervention to reduce adverse outcomes.