New study reveals link between physical fitness and mental health in adults with ADHD

Greater physical fitness is associated with better mental health among individuals with attention-deficit/hyperactivity disorder (ADHD), according to new research published in the Journal of Attention Disorders.

ADHD, a common neurodevelopmental disorder, affects a significant portion of the global adult population. Many individuals with ADHD also experience mental illnesses such as depression, anxiety disorders, substance use disorders, and personality disorders. But treating ADHD in the presence of comorbid mental illnesses can be challenging due to the potential negative interactions between medications used for each condition.

Traditional pharmacotherapy for managing both ADHD and mental illnesses may not be recommended due to these drug interactions and side effects. The new study aimed to explore alternative treatment approaches that incorporate physical activity, which has shown promise in improving symptoms of ADHD and mental illnesses with minimal side effects.

“The experiences of adults with ADHD have been understudied in health and exercise psychology. It’s important to recognize that our bodies and brains are connected, and understand how this relates to mental health,” said study author Michelle Ogrodnik, a PhD candidate at McMaster University and member of the Neurofit Lab.

The researchers conducted the study with a group of 85 young adults aged 18 to 35 from Canada. The participants completed various assessments and questionnaires related to ADHD symptoms, mental health, and cardiorespiratory fitness. To be eligible for the study, participants needed to be fluent in English, have access to a computer and the internet, and not have a disorder affecting color vision.

While participants with comorbid mental illnesses were included, those with additional neurodevelopmental diagnoses such as autism spectrum disorder were excluded. Participants in the ADHD group required a self-reported formal diagnosis from a healthcare professional, while the control group needed to score below a certain threshold on the ADHD symptom assessment.

The researchers used the Conner’s Adult ADHD Rating Scale (CAARS) to assess ADHD symptoms. The CAARS is a self-report questionnaire consisting of 30 items that participants ranked based on increasing severity of symptoms. A score of 65 or higher on the CAARS indicated the presence of ADHD. To assess mental health and well-being, the Depression Anxiety and Stress Scale (DASS) was used. The DASS consisted of 42 items that evaluated the severity of depression, anxiety, and perceived stress symptoms.

Cardiorespiratory fitness was estimated using the six-minute walk test (6MWT). Participants used a mobile application called “6WT” to record the distance walked during the test. The distance, along with self-reported body weight, sex, age, and resting heart rate measurements, were used to estimate participants’ maximal oxygen consumption (VO2 max), which is an indicator of cardiorespiratory fitness.

In addition to estimating cardiorespiratory fitness, participants also reported their perceived fitness by rating themselves on a scale from “Excellent” to “Poor.” Perceived fitness served as a secondary estimate of fitness in this study.

The researchers found that participants with ADHD had worse mental health compared to the control group, highlighting the high prevalence of mental health issues in adults with ADHD and the potential treatment gap in mental health support for this population. Approximately 67% of participants with ADHD reported moderate to extremely severe symptoms of depression, anxiety, or perceived stress, while only around 36% of the control group reported similar symptoms.

Higher cardiorespiratory fitness was associated with with less depression, anxiety, and perceived stress, particularly for individuals with milder ADHD symptoms. Higher perceived fitness was associated with less depression, anxiety, and perceived stress for both ADHD and control groups. Importantly, the relationship between perceived fitness and depression was stronger for individuals with ADHD compared to those without ADHD.

“Adults with ADHD self-reported significantly poorer mental health than participants without ADHD. However, having higher physical fitness was associated with better mental health,” Ogrodnik told PsyPost.

But it is important to note that the findings are based on a cross-sectional study, and further research is needed to establish causal relationships and explore the potential benefits of physical fitness interventions for individuals with ADHD.

“This research supports that higher physical fitness is associated with better mental health, but it cannot tell us whether improving physical fitness can lead to improved mental health or exactly how these two are connected, which should be a focus of future research,” Ogrodnik explained.

The researchers suggested that there might be a bidirectional relationship between mental health and physical fitness. Improving one’s physical fitness might help to alleviate mental health symptoms. One the other hand, individuals experiencing mental health challenges may have reduced motivation, energy, or interest in maintaining a regular exercise routine.

To establish a clearer understanding of the relationship between mental health, physical fitness, and ADHD, Ogrodnik and her colleagues suggest conducting randomized controlled trials.

“I want to recognize and appreciate the participants who were involved in this project, for their willingness to engage with our research,” Ogrodnik said. “Science couldn’t happen without them!”

“It is also important to acknowledge that while investigating support strategies is important, this is just one piece of the puzzle; we need to continue shifting societal ideas, norms, and spaces to reduce pressures that have negative impacts on mental health in the first place,” she added.

The study, “Mental Health in Adults With ADHD: Examining the Relationship With Cardiorespiratory Fitness“, was authored by Michelle Ogrodnik, Sameena Karsan, and Jennifer J. Heisz.

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