Authors: Annie I. Reiner (1Department of Psychology, University of Alabama, Tuscaloosa, AL, USA), Alex J. Greenberg (1Department of Psychology, University of Alabama, Tuscaloosa, AL, USA), Matthew A. Jarrett (1Department of Psychology, University of Alabama, Tuscaloosa, AL, USA), Stephen P. Becker (2Division of Behavioral Medicine and Clinical Psychology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA; 3Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA), Michael J. Kofler (4Department of Psychology, Florida State University, Tallahassee, FL, USA), Aaron M. Luebbe (5Department of Psychology, Miami University, Oxford, OH, USA), G. Leonard Burns (6Department of Psychology, Washington State University, Pullman, WA, USA), Annie A. Garner (7Department of Psychology, Saint Louis University, St. Louis, MO, USA)
Categories: Article, ADD/ADHD, rumination, attention-deficit/hyperactivity disorder, depression, stimulants
Source: Journal of attention disorders
Authors: Annie I. Reiner, Alex J. Greenberg, Matthew A. Jarrett, Stephen P. Becker, Michael J. Kofler, Aaron M. Luebbe, G. Leonard Burns, Annie A. Garner
Previous research suggests that college students with attention-deficit/hyperactivity disorder (ADHD) symptoms are at risk for experiencing ruminative thinking. Although research has shown that stimulant medications reduce ADHD symptoms, no research has looked at whether stimulant medication moderates the association between ADHD symptoms and rumination. Given this gap in the literature, the current study examined whether stimulant medication status moderates the association between ADHD symptoms and rumination. Participants (N = 4,751) were undergraduate psychology students from six universities (70.0% female; Mage = 19.08; SDage = 1.36) who participated in a larger study. College students completed questionnaires related to ADHD symptoms and rumination and indicated whether they were currently taking a stimulant medication. Results of the moderation model indicated a significant main effect for ADHD inattentive symptoms (β = 5.20, p < .05, 95% CI [4.43, 5.98]) and a significant interaction effect between ADHD inattentive symptoms and stimulant medication in relation to rumination (β = −2.41, p < .05, 95% CI [−4.51, −.30]). Examination of conditional effects revealed significant simple slopes for students both on and off medication but a stronger association for those off (β = 5.20, p < .05, 95% CI [4.43, 5.98]) versus on (β = 2.80, p < .05, 95% CI [.78, 4.81]) stimulant medication. Stimulant medication status did not moderate the association between ADHD hyperactive/impulsive symptoms and rumination. Future research should continue to explore the potential benefits of stimulant medication for reducing the association between ADHD inattention symptoms and rumination.
Attention-deficit/hyperactivity disorder (ADHD) is a neuro-developmental disorder that includes symptoms of inattention, hyperactivity, and impulsivity (American Psychiatric Association, 2013). Although ADHD was once perceived as a condition limited to childhood, a substantial proportion of adults still experience significant levels of ADHD symptoms along with functional impairments (Kooij et al., 2016; Sibley et al., 2016). The percentage of individuals diagnosed with ADHD, which has been increasing within the last several years (London & Landes, 2021), is about 10.2% in children (Abdelnour et al., 2022) and 6.76% in adults (Song et al., 2021). Individuals with ADHD exhibit deficits in several domains, including social impairments (de Boo & Prins, 2007), academic difficulties (Daley & Birchwood, 2010), and emotion dysregulation (Bunford et al., 2015). Various treatment options, both pharmacological and nonpharmacological, exist for individuals with ADHD across the lifespan (Drechsler et al., 2020).
ADHD frequently co-occurs with other mental health problems; research has shown that college students with ADHD are more likely to have co-occurring mental health conditions than non-diagnosed individuals (Anastopoulos et al., 2018). More specifically, ADHD often co-occurs with internalizing disorders such as anxiety disorders and depression (Choi et al., 2022).
Although there are many reasons for the co-occurrence of ADHD and internalizing diagnoses, one transdiagnostic factor to consider is what has been termed task-unrelated thought. Broadly, task-unrelated thought includes the content and pattern of thoughts that are irrelevant to the current task in which the individual is taking part (Christoff et al., 2016). Previous research suggests that people who are diagnosed with ADHD are at increased risk for experiencing task-unrelated thoughts (Bozhilova et al., 2018; Fredrick et al., 2020), specifically mind-wandering (Biederman, Lanier, et al., 2019; Lanier et al., 2021; Seli et al., 2015). Additionally, college students with elevated ADHD symptoms are more likely to display ruminative thinking patterns which are distinct from mind-wandering (Jonkman et al., 2017; Yeguez et al., 2018). Mind-wandering is off-task thought that can occur either with or without intention (Smallwood & Schooler, 2006). Ruminative thinking is the way of responding to a negative mood in which an individual analyzes their low mood and comes up with the possible consequences and implications of these feelings (Nolen-Hoeksema, 1991). Thus, the main difference between these two constructs is that mind-wandering is a form of free, unguided, internal thought, whereas rumination includes cognitions that focus on a specific topic (Christoff et al., 2016; Irving, 2016). Although less researched than mind-wandering and ADHD, studies have found that rumination is associated with suicidal ideation in emerging adults exhibiting elevated ADHD symptoms (Yeguez et al., 2018). Additionally, the evidence base provides support that ADHD-diagnosed adults who report less ruminative thinking patterns and less therapy avoidance are significantly less likely to develop co-occurring depression (Oddo et al., 2018). Therefore, it is important to investigate the association between ADHD and rumination.
Compared to the literature exploring the association between mind-wandering and ADHD symptoms, there has been significantly less research on the association between ADHD symptoms and ruminative thinking patterns (Fredrick et al., 2020). Additionally, although one study found that stimulant medication significantly decreased the risk for anxiety, depressive, and disruptive disorders in male youth with ADHD (Biederman, DiSalvo, et al., 2019), no research has looked at whether stimulant medication moderates the association between ADHD symptoms and rumination. Given that stimulant medication improves attentional control, it may be that stimulant medication reduces the strength of the association between ADHD symptoms and rumination. To address this question, the current study explored the association between ADHD symptoms and ruminative thinking while considering stimulant medication status. We hypothesized that stimulant medication status would moderate the association between ADHD symptoms and rumination such that those who were on stimulant medication would show a weaker association between ADHD symptoms and rumination than those who were not on stimulant medication.
Participants (N = 4,751) were undergraduate psychology students from six universities across several regions in the United States (30.0% male; Mage = 19.08; SDage = 1.36). These students were enrolled in a larger study examining ADHD symptoms, co-occurring symptoms, and domains of functioning in college students. As summarized in Table 1, the majority of participants self-identified as female (70%), White (81%), and non-Hispanic (90%). Approximately half (58%) were in their first year of college. The majority of participants (88%) reported that they did not typically take any medications for attentional, learning, or behavioral difficulties, while 6.6% indicated that they typically take a stimulant medication. Additionally, 9.1% of participants indicated that they had been professionally diagnosed with ADHD at some point in their lives.
Data were collected during the 2016 to 2017 academic year. The study was approved by each university’s local Institutional Review Board (IRB). Participants in psychology courses at the time the study was being conducted were able to read a brief description of the study posted online and sign up to receive a link to complete questions via Qualtrics. Five of the six universities administered an online questionnaire on Qualtrics with study measures included, while students attending the sixth university selected available time slots to give in-person consent and then completed the same set of questionnaires online in the laboratory environment. Participants received course credit after completing the survey.
The Barkley Adult ADHD Rating Scale-IV (BAARS-IV; Barkley, 2011) consists of 27 questions and 4 subscales derived from the DSM-IV criteria for ADHD (American Psychiatric Association, 2013). Participants rate the frequency with which they have experienced each ADHD symptom on a 4-point scale from “Never or Rarely” to “Very Often.” The factor structure of this measure has been derived from a nationally representative sample of adults, and the scales exhibit satisfactory to excellent internal consistency and adequate test-retest reliability throughout a 2- to 3-week time period (Barkley, 2011). For the current study, the Inattention and Hyperactivity/Impulsivity subscales were utilized.
Rumination was measured using the Ruminative Responses Scale (RRS) of the Response Style Questionnaires (RSQ; Nolen-Hoeksema, 1991). The RSQ contains 71 items grouped into Ruminative Responses, Distracting Responses, Problem-Solving, and Dangerous Activities scales. However, due to our research question, the present study only included items within the RRS. This scale includes 22 items that measure one’s response to depressed mood, including responses that emphasize the self (e.g., “I think back to other times I have been depressed”), one’s symptoms (e.g., “I think about how hard it is to concentrate”), and the possible consequences and causes of one’s mood (e.g., “I think, ‘I won’t be able to do my job if I don’t snap out of this’”). Individuals rate each item on a 4-point scale from “Almost Never” to “Almost Always,” with higher scores indicating greater propensity to ruminate due to feeling sad. The RSS has shown good internal consistency and construct validity and moderate test-retest reliability over a 6-month period with a college student sample (Roelofs et al., 2006).
The Depression Anxiety Stress Scales-21 (DASS-21; Antony et al., 1998) was used in the current study to measure depression symptoms. Participants rated each item in reference to the past week on a 4-point scale (0 = did not apply to me at all, 3 = applied to me very much or most of the time). The DASS-21 has shown acceptable internal consistency and concurrent validity with similar measures of anxiety and depression (Antony et al., 1998; Lovibond & Lovibond, 1995).
Medication status was assessed via a demographic questionnaire (i.e., “Do you typically take any medications for attentional, learning, or behavioral difficulties?”) that included a textbox where participants typed the names of their current medications. Responses were coded to reflect whether participants did not (code = 0) or did (code = 1) take a stimulant medication.
An instructional manipulation check (IMC), trap questions, and questions assessing individuals’ effort were utilized during the Qualtrics questionnaire to enhance response quality. The IMC question asks the individual to choose a specific answer to a question before advancing through the remainder of the survey (e.g., the instructions asking you to choose a specific sport rather than responding to a question about selecting your favorite sport). This IMC question was only administered once at the start of the survey to emphasize the importance of reading instructions to the participant. In addition to the IMC, trap questions were included in the Qualtrics questionnaires which included the answer for the individual to select (e.g., “If you are reading closely, select ‘very much’”). Additionally, a question at the end of the survey asked individuals to state the amount of effort they put into the study overall. A minimum of 50% accuracy or higher for the trap questions and an effort rating of at least 5 on a 0 to 10 scale (0 = not much effort, 10 = my best effort) was required. The same minimum has been utilized with prior college student samples (Becker et al., 2018) to identify individuals who gave sufficient effort while also including participants who sometimes exhibit lapses in attention. In the current study, 204 out of 4,955 participants (4.1%) were excluded based on these screening procedures.
Data were initially screened for missing data. Out of the 4,751 participants in the study, 4,620 had full data for study analyses (97%). Given this relatively small degree of missing data (3%) and the large sample size, we chose to pursue listwise deletion for analyses. Study analyses involved correlation analyses between variables of interest and regression analyses conducted via SPSS Version 29. The SPSS PROCESS macro was utilized for moderation analyses (Hayes, 2013).
Pearson correlation coefficients for the main study variables are presented in Table 2. Inattention (r = .46, p < .05) and Hyperactivity/Impulsivity (r = .30, p < .05) symptoms were significantly and positively correlated with rumination. Stimulant medication usage was significantly and positively correlated with Inattention (r = .23, p < .05) and Hyperactivity/Impulsivity (r = .17, p < .05). For demographic variables, correlations were generally in the “small” range but still significant in some cases. For example, age was significantly and positively correlated with ADHD symptoms and rumination (rs = .02–.05). Sex (coded 0 = male, 1 = female) was positively correlated with rumination (r = .04, p < .05), and race (coded 0 = persons of color, 1 = White) was negatively correlated with rumination (r = −.07, p < .05). Given these significant correlations, these variables were controlled for in subsequent analyses. In addition, given the strong association between depression and rumination (r = .64, p < .05), we also controlled for depression symptoms in our analyses.
Regression analyses examining moderation were conducted via the PROCESS macro for SPSS using Model 1 for simple moderation. Cases with missing data were excluded from analyses via listwise deletion. Age, sex, race, and DASS-21 depression symptoms were included as covariates given that these variables were significantly correlated with either ADHD symptoms or rumination. Results of the moderation model indicated a significant main effect for ADHD inattention symptoms (β = 5.20, p < .05, 95% CI [4.43, 5.98]) but not stimulant medication status (β = 3.41, p > .05, 95% CI [−1.23, 8.05]). There was a significant interaction effect between ADHD inattention symptoms and stimulant medication status for predicting rumination (β = −2.41, p < .05, 95% CI [−4.51, −.30]). Examination of conditional effects revealed significant positive simple slopes for those both on and off medication but a stronger association for those off (β = 5.20, p < .05, 95% CI [4.43, 5.98]) versus on (β = 2.80, p < .05, 95% CI [.78, 4.81]) stimulant medication.
For hyperactivity/impulsivity, results of the moderation model indicated a significant main effect for ADHD hyperactivity/impulsivity symptoms (β = 3.50, p < .05, 95% CI [2.75, 4.24]) but not stimulant medication status (β = −4.00, p > .05, 95% CI [−8.75, .77]). There was not a significant interaction effect between ADHD hyperactivity/impulsivity symptoms and stimulant medication status for predicting rumination (β = 1.65, p < .05, 95% CI [−.64, 3.95]).
Additional exploratory analyses were conducted examining the Brooding and Reflection subscales of the RRS with ADHD inattention symptoms as a predictor and stimulant medication status as a moderator. Results of the moderation model for Brooding indicated a significant main effect for ADHD inattention symptoms (β = 1.14, p < .05, 95% CI [.93, 1.36]) but not stimulant medication status (β = 1.08, p > .05, 95% CI [−.20, 2.36]). The interaction effect between ADHD inattention symptoms and stimulant medication status for predicting Brooding was not significant (β = −.55, p > .05, 95% CI [−1.14, .03]). Results of the moderation model for Reflection indicated a significant main effect for ADHD inattention symptoms (β = .64, p < .05, 95% CI [.42, .85]) but not stimulant medication status (β = 1.13, p > .05, 95% CI [−.16, 2.42]). There was a significant interaction effect between ADHD inattention symptoms and stimulant medication status for predicting Reflection (β = −.76, p < .05, 95% CI [−1.34, −.17]). Examination of conditional effects revealed a significant positive simple slope for those off of medication (β = .64, p < .05, 95% CI [.42, .85]). For those on medication, the association between ADHD inattention symptoms and Reflection was not significant (p > .05).
Our study aimed to explore the associations among medication status, ADHD symptoms, and rumination. To our knowledge, no study to date has investigated how stimulant medication moderates the association between ADHD symptoms and rumination. First, self-reported ADHD inattention symptoms (r = .46) and hyperactivity/impulsivity symptoms (r = .30) were both moderately, significantly and positively correlated with rumination. These findings parallel prior research suggesting that college students with elevated ADHD symptoms are at increased risk for experiencing ruminative thinking (Jonkman et al., 2017; Yeguez et al., 2018).
Beyond this direct association, we explored whether usage of stimulant medication alters the strength of the association between ADHD symptoms and rumination. Consistent with our hypothesis, the data supported a stronger association between ADHD and rumination among participants who were not taking stimulant medication relative to those taking stimulant medication. Further, analyses revealed that this moderating effect held only for ADHD inattention and not hyperactivity/impulsivity. In addition, in subsequent analyses, this effect was found for the Reflection subscale of a measure of rumination (RRS) but not the Brooding subscale. Although the Brooding subscale is thought to reflect one’s comparison of self to some unachieved standard, the Reflection subscale is thought to reflect ruminative attempts to engage in problem-solving to alleviate depression symptoms. Our finding suggests that stimulant medication may reduce the association between ADHD inattention and this particular form of rumination.
Although additional research is needed to draw firmer conclusions, one implication of our finding is that emerging adults with ADHD inattention symptoms may ruminate less when taking stimulant medications. Future research should look to highlight the mechanisms by which stimulant medication may impact rumination and to further explore the direct effects of stimulants on rumination in those with ADHD. For example, perhaps stimulant medications improve attentional control which has a beneficial effect on limiting rumination. Simultaneously, given that ADHD inattention symptoms are still linked with greater rumination even when individuals are taking stimulant medication underscores the need for additional treatment for rumination in the context of ADHD (e.g., cognitive-behavioral therapy). Additionally, our study emphasizes the importance of probing for and targeting internalizing symptoms in individuals with ADHD. When addressing ruminative thoughts, clinicians might consider engaging in determining the content of the rumination (e.g., social or academic functioning), then consider addressing this with a combination of stimulants and psychosocial intervention such as cognitive behavioral therapy. Given our finding that the moderation effect of stimulant medication on the association between ADHD symptoms and rumination was found for symptoms of ADHD inattention but not hyperactive/impulsive symptoms, future research might examine cognitive disengagement syndrome (CDS) symptoms which are highly correlated with but distinct from ADHD inattention symptoms (Becker, 2021; Becker et al., 2023). Future research could also focus on refining theoretical models that explain how ADHD symptoms and rumination interact; for example, exploring how executive functioning deficits—a core feature of ADHD—mediate or moderate the association between ADHD symptoms and rumination could provide a deeper understanding of the shared mechanisms at play. Furthermore, findings suggest the need for a methodology that includes clinical samples followed longitudinally to establish causality; for example, future research utilizing this method could explore if there are certain developmental periods where stimulant medication is most effective in moderating the association between rumination and ADHD symptoms. Finally, additional studies could explore the role of stimulant medication in addressing potential mechanisms that may explain the co-occurrence of ADHD with internalizing mental health symptoms and suicide risk.
Our findings should be considered within the context of the study limitations. First, since our sample was a non-clinical sample, results cannot be assumed to extend to a clinical sample (e.g., those formally diagnosed with ADHD). Relatedly, our sample had only a small portion of participants who endorsed regular usage of a stimulant medication (i.e., 6.6%). It is also important to note the lack of representativeness of the sample given that the majority of participants self-identified as female (70%), White (81%), and non-Hispanic (90%). In addition, stimulant medication usage frequency, duration, and dosage were not measured and all data in the current study were based on self-report. Finally, it is possible that undergraduate students are unique in their environmental and individual differences that may limit external validity when making claims about emerging adults in general (e.g., those who are not in college). While there are limitations to the study, we hope that our findings will spur continued research on the link between ADHD and rumination in college students along with new treatment approaches to support those with both ADHD and rumination.