Date of Submission


Degree Type


Degree Name

Doctor of Psychology (PsyD)




Sluggish cognitive tempo (SCT) is a recently identified mental health construct. Currently, no widely accepted diagnostic criteria for SCT exist, and it is not recognized in the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5). There is debate in the psychological community as to whether SCT is better conceptualized as an atypical presentation of attentiondeficit/ hyperactivity disorder (ADHD) or a unique symptom cluster comprised of ADHD and additional psychological and neurocognitive symptoms. When controlling for ADHD symptomatology, SCT has been found to be associated with internalizing symptoms, such as anxiety and depression, as well as impaired cognitive functioning, such as deficits in executive function and slow processing speed. The current study examined groups of adults diagnosed with varying levels of ADHD and SCT symptomatology to determine whether they differed in their internalizing symptoms and cognitive functioning. Analyses indicated subjects with clinical levels of both ADHD and SCT had higher scores on measures of internalizing symptoms and executive dysfunction than those with ADHD and subclinical symptoms of SCT or those with ADHD only. Regression analyses identified symptoms of depression and executive dysfunction that significantly predicted subjects SCT symptoms. It is hoped the current study will inform the assessment and treatment of adults with ADHD, SCT, and internalizing symptoms.