Objective: To examine the cognitive disengagement syndrome (CDS) symptoms of mothers of children with attention-deficit/hyperactivity disorder (ADHD). Method: The participants consisted of 223 mothers of children with ADHD, and data were collected using the Structured Clinical Interview for DSM-5 Disorders-Clinician Version (SCID-5-CV), the Stroop Test (ST), the Barkley Adult SCT Scale (CDS), and the Adult ADHD Self-Report Scale (ASRS). Results: The participants were divided into four groups based on psychopathology: the group without any psychiatric disorder, the group with only ADHD, the group with a psychiatric disorder other than ADHD, and the group with another psychiatric disorder along with ADHD. The group with any psychiatric disorder along with ADHD had the highest CDS scores, while the group without any psychopathology had the lowest CDS scores. Conclusion: CDS seems to be a construct associated with both ADHD and other internalizing disorders. Further studies are needed to shed more light on these relationships.