Influence of Atomoxetine on Relationship Between ADHD Symptoms and Prefrontal Cortex Activity During Task Execution in Adult Patients

Atsunori Sugimoto; Yutaro Suzuki; Kiyohiro Yoshinaga; Naoki Orime; Taketsugu Hayashi; Jun Egawa; Shin Ono; Takuro Sugai; Toshiyuki Someya

doi:10.3389/fnhum.2021.755025

Influence of Atomoxetine on Relationship Between ADHD Symptoms and Prefrontal Cortex Activity During Task Execution in Adult Patients

Front Hum Neurosci. 2021 Nov 26:15:755025. doi: 10.3389/fnhum.2021.755025. eCollection 2021.

Authors

Atsunori Sugimoto^{1

2}, Yutaro Suzuki^{3

4}, Kiyohiro Yoshinaga^{2

5}, Naoki Orime³, Taketsugu Hayashi^{2

5}, Jun Egawa⁵, Shin Ono^{1

2}, Takuro Sugai⁶, Toshiyuki Someya⁵

Affiliations

¹ Department of Community Psychiatric Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
² Department of Psychiatry, Niigata Psychiatric Center, Nagaoka, Japan.
³ Department of Psychiatry, Niigata University Medical and Dental Hospital, Niigata, Japan.
⁴ Department of Psychiatry, Suehirobashi Hospital Keiaikai, Niigata, Japan.
⁵ Department of Psychiatry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
⁶ Comprehensive Medical Education Center, Niigata University School of Medicine, Niigata, Japan.

Abstract

Objective: We conducted this non-randomized prospective interventional study to clarify the relationship between improved attention-deficit hyperactivity disorder (ADHD) symptoms and regional brain activity. Methods: Thirty-one adult patients underwent near-infrared spectroscopy examinations during a go/no-go task, both before and 8 weeks after atomoxetine administration. Results: Clinical symptoms, neuropsychological results of the go/no-go task, and bilateral lateral prefrontal activity significantly changed. A positive correlation was observed between right dorsolateral prefrontal cortex activity and Conners' Adult ADHD Rating Scales scores. Before atomoxetine administration, no correlations between prefrontal cortex activity and clinical symptoms were observed in all cases. When participants were divided into atomoxetine-responder and non-responder groups, a positive correlation was observed between prefrontal cortex activity and clinical symptoms in the non-responder group before treatment but not in the responder group, suggesting that non-responders can activate the prefrontal cortex without atomoxetine. Conclusions: Individuals with increased ADHD symptoms appear to recruit the right dorsolateral prefrontal cortex more strongly to perform the same task than those with fewer symptoms. In clinical settings, individuals with severe symptoms are often observed to perform more difficultly when performing the tasks which individuals with mild symptoms can perform easily. The atomoxetine-responder group was unable to properly activate the right dorsolateral prefrontal cortex when necessary, and the oral administration of atomoxetine enabled these patients to activate this region. In brain imaging studies of heterogeneous syndromes such as ADHD, the analytical strategy used in this study, involving drug-responsivity grouping, may effectively increase the signal-to-noise ratio.

Keywords: Conners’ adult ADHD rating scales; atomoxetine; attention-deficit/hyperactivity disorder; go/no-go task; near-infrared spectroscopy; responder group; response inhibition task.