Treatments and Treatment Predictors in Patients With Substance Use Disorders and Comorbid Attention-Deficit/Hyperactivity Disorder: First Results From the International Naturalistic Cohort Study of ADHD and SUD (INCAS).

Background

Treatment of attention-deficit/ hyperactivity disorder (ADHD) in patients with a substance use disorder (SUD) and comorbid ADHD (SUD +ADHD) may have positive effects on the outcome of both conditions, but controversy exists regarding the preferred ADHD treatment in these patients. Little is known about the treatments that are provided for these patients in routine addiction care practice and the factors that are associated with treatment provision.

Objective

To describe the treatments provided in everyday clinical practice and to explore factors associated with ADHD treatment provision in patients with SUD +ADHD.

Methods

An international multicenter observational prospective cohort design was employed. Patients with moderate to severe SUD and comorbid ADHD according to DSM-5 were invited to participate at the start of a new SUD treatment episode between June 2017 and May 2021. Clinical and sociodemographic data were collected at 12 study sites in 9 countries through patient interviews, interviews with treatment providers, and patient files. Treatment variation across studies was described, and mixed-effect logistic regression was used to identify factors associated with ADHD treatment provision.

Results

A total of 578 treatment-seeking patients with SUD +ADHD (274 inpatients, 303 outpatients, and 1 unknown) were recruited. About two thirds received some kind of ADHD treatment (62.8%), with 54.0% receiving pharmacologic, 34.0% receiving psychological treatment, and 25.1% receiving combined pharmacologic and psychological treatment. The treatment site explained more of the variation in ADHD treatment provision than individual patient factors. In addition, higher ADHD symptom severity and sobriety at intake were associated with receiving ADHD treatment.

Conclusion

These findings suggest that treatment of SUD +ADHD patients is suboptimal even in specialized centers with substantial practice variation. Further research is needed to better understand the barriers to implement treatment guidelines for ADHD + SUD and, thus, to improve quality of care. Trial Registration: ISRCTN: 15998989 20/12/2019 (https://doi.org/10.1186/ISRCTN15998989).