A PRELIMINARY EXAMINATION ON TREATMENT EFFECTIVENESS OF AUGMENTATION WITH ATTENTION DEFICIT HYPERACTIVITY DISORDER (ADHD) AGENTS IN PATIENTS WITH OBSESSIVE-COMPULSIVE DISORDER AND COMORBID ADHD
Authors: Ogino *Shun , Mukai Keiichiro , Miyauchi Masahiro , Hashimoto Takuya , Hosoi Yukihiko , Sakurai Masahiko , Matsunaga Hisato 
Published: February 2025

Abstract

Background
Obsessive-compulsive disorder (OCD) is a psychiatric disorder characterized by obsessions and compulsions, with a reported lifetime morbidity of approximately 2%–3%. OCD can severely interfere with daily and social life, and comorbidity with other psychiatric disorders, such as depression, is high. Attention deficit hyperactivity disorder (ADHD), a triad of hyperactivity, impulsivity, and inattention, is reported to account for at least 2.8% of the adults, regardless of geographic region or culture.
Psychiatric comorbidity is common in adult ADHD population, and approximately 13% of OCD patients have comorbid ADHD. However, obsessive-compulsive symptoms may often act as an internal brake on the inattention and impulsivity of ADHD, making the diagnosis of ADHD difficult if obsessive-compulsive symptoms are foregrounded. Thus, in the case of OCD patients with comorbid ADHD in adulthood, co- existing ADHD may often be overlooked or underdiagnosed, and only OCD may be diagnosed, because ADHD are more likely to wane into adulthood (e.g., hyperactivity). Therefore, we should take into account the possibility that a hidden ADHD pathology may cause considerable influence on the clinical features in adult OCD patients.
Nevertheless, there is no standardized treatment strategies for OCD patients with comorbid ADHD, and, in our previous study, the improvement rate of OCD patients with comorbid ADHD was lower than those without ADHD using the standard combination treatment of OCD (1). There is a small number of case reports have demonstrated the efficacy of concomitant ADHD agents.

Aims & Objectives
To evaluate the efficacy of non-stimulant ADHD agents such as guanfacine or atomoxetine in OCD patients with comorbid ADHD, we performed the open trial adding ADHD agent to the standardized pharmacotherapy of OCD such as SSRI or SSRI with antipsychotic augmentation.

Methods
Twenty-one adult OCD patients who were newly diagnosed as having comorbid ADHD were recruited in this study. The Yale Brown Obsessive Compulsive Scale (Y-BOCS) was performed to assess the severity of obsessive-compulsive symptoms at the initiation of ADHD medication and after 3 months, and the rate of symptom improvement was retrospectively evaluated.

Results
The mean reduction score of Y-BOCS was 9.2 points, and 14 of 21 patients (67%) exhibited the improvement rate over 25% with a statistically significance.

Discussion & Conclusion
The augmentation strategy using non-stimulant ADHD agent may be effective in the treatment for OCD symptoms in treatment-refractory OCD patients especially those with comorbid ADHD. To verify the hypothesis, further prospective RCT studies should be required.

Limitations
The present study was performed based on a retrospective chart-review and no standardized use of ADHD agent was conducted. Additionally, it excluded OCD patients who had already been diagnosed with ADHD and were already on any ADHD medication, and limiting the use of ADHD medications to non- stimulants.

References
1)Miyauchi M et al. A prospective investigation of impacts of comorbid attention deficit hyperactivity disorder (ADHD) on clinical features and long-term treatment response in adult patients with obsessive- compulsive disorder (OCD), Comprehensive Psychiatry125(1):152401 DOI: 1016/j.comppsych.2023.152401