Dissertation
Sluggish cognitive tempo as a transdiagnostic link between adult ADHD and internalizing symptoms
University of Iowa
Doctor of Philosophy (PhD), University of Iowa
Spring 2021
DOI: 10.17077/etd.005966
Abstract
Objective. To examine Sluggish Cognitive Tempo (SCT) as a transdiagnostic link between attention-deficit/hyperactivity disorder (ADHD) symptoms and internalizing symptoms in college students. Associations of SCT (at both the between-person and within-person level) and ADHD, internalizing symptoms, and cognitive functioning were examined. Furthermore, SCT symptoms (SCT-between and SCT-within) were evaluated as mediators of the overlap between ADHD and internalizing symptoms, and as mediators of the overlap between cognitive functioning and ADHD/internalizing symptoms.
Methods. One hundred and fifty-eight college students (62.7% female; 78.3% Caucasian; age: M= 18.79 [SD= 1.21] years) recruited from the University of Iowa Psychology Department Research Pool completed questionnaires assessing ADHD, SCT, and externalizing symptoms, ratings of executive functioning, and several cognitive tasks assessing IQ, processing speed, reaction time variability, set-shifting, response inhibition, working memory, and reward and punishment sensitivity. Additionally, participants completed an Ecological Momentary Assessment (EMA) of their SCT symptoms (four times per day for seven days), followed by a final online survey of internalizing symptoms (anxiety and depression). First, analyses were conducted to establish the reliability and validity of the Adult Concentration Inventory (ACI) when measuring SCT at multiple time points versus one global rating. Second, associations between SCT variables and ADHD, internalizing symptoms, and cognitive functioning (tasks and ratings) were examined via partial correlations. Follow-up hierarchical regression models were then conducted to determine if the within index of SCT added to the association over and above that of the between index of SCT. Third, multiple mediation analyses were conducted to evaluate the impact of ADHD symptoms on internalizing symptoms via SCT symptoms. Finally, multiple mediation analyses were conducted to evaluate the impact of cognitive functioning on ADHD and internalizing symptoms via SCT symptoms.
Results. The ACI demonstrated adequate validity and reliability. Partial correlations revealed that SCT indices (between- and within-person scores) were not correlated with any of the cognitive tasks; however, SCT indices were significantly correlated with all ratings of executive functioning (Barkley Deficits in Executive Functioning Scale; BDEFS). Moreover, SCT indices were significantly associated with depression, anxiety, and current and childhood ADHD symptoms. After controlling for internalizing and ADHD symptoms, the SCT-between index was still significantly associated with problems in time management, organization, and restraint, while SCT-within index was still significantly associated with problems in motivation. Follow-up regression models showed that even after controlling for age, sex, BDI, BAI, and all ADHD symptoms, SCT-within significantly predicted motivation and SCT-between significantly predicted time management, organization, and restraint. Multiple mediation analyses indicated that ADHD symptoms influence internalizing symptoms via SCT-between. Models also indicated that problems in executive functioning (time management and organization) influenced internalizing symptoms via SCT-between.
Conclusions. The pattern of findings supports the transdiagnostic utility of SCT as a link between ADHD and internalizing symptoms. Notably, SCT served as a mediator of the overlap between ADHD and anxiety/depression, and between certain cognitive deficits and internalizing symptoms. Furthermore, it appears that fluctuations in SCT may be particularly important in understanding motivation deficits in college students. Theoretical and clinical implications are discussed.
Details
- Title: Subtitle
- Sluggish cognitive tempo as a transdiagnostic link between adult ADHD and internalizing symptoms
- Creators
- Jaclyn M Kamradt
- Contributors
- Molly A Nikolas (Advisor)Teresa Treat (Committee Member)Daniel Tranel (Committee Member)Kelli Ryckman (Committee Member)Kristian Markon (Committee Member)
- Resource Type
- Dissertation
- Degree Awarded
- Doctor of Philosophy (PhD), University of Iowa
- Degree in
- Psychology
- Date degree season
- Spring 2021
- DOI
- 10.17077/etd.005966
- Publisher
- University of Iowa
- Number of pages
- x, 112 pages
- Copyright
- Copyright 2020 Jaclyn M. Kamradt
- Language
- English
- Description illustrations
- illustrations
- Description bibliographic
- Includes bibliographical references (pages 88-112)
- Public Abstract (ETD)
Attention-deficit/hyperactivity disorder (ADHD), characterized by age-inappropriate overactivity, impulsivity, inattention, and disorganization, persists into adulthood in well over 50% of cases. Adults with ADHD often suffer from increased anxiety and depression (internalizing disorders). Critically, adults with ADHD and co-occurring anxiety and depression exhibit a diminished treatment response and worse health outcomes. Identifying factors that contribute to this overlap between ADHD and internalizing symptoms would allow for improvement of conceptualization, assessment, and treatment of adult ADHD. One such factor may be Sluggish Cognitive Tempo (SCT), a set of symptoms including daydreaming, feeling spacey, and moving/behaving slowly, because these symptoms are present in up to half of individuals with ADHD, are strongly correlated with both anxiety and depression, and may involve similar cognitive deficits as ADHD and internalizing problems. This project found that SCT was associated with increased ADHD symptoms, anxiety and depression symptoms, and problems in cognition. Additionally, ADHD influenced anxiety and depression via SCT. Problems in certain cognitive domains (time management problems and organization problems) also influenced anxiety and depression via SCT. Results further highlighted that having increased fluctuation in SCT symptoms over time was associated with increased motivation problems. Taken together, results from the present study found that SCT may be a link, or transdiagnostic construct, bridging mental health comorbidities and bridging cognitive dysfunction and internalizing psychopathology.
- Academic Unit
- Psychological and Brain Sciences
- Record Identifier
- 9984124270402771
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