December 5, 2021

Two meta-analyses suggest physical exercise is an effective tool in treating ADHD

Two recent meta-analyses, one by an Asian team, and the other by a European team, have reported encouraging results on the efficacy of physical exercise in treating ADHD among children and adolescents.

One, a Hong Kong-based team (Liang et al. 2021) looked at the effect of exercise on executive functioning.

The team identified fifteen studies with a combined total, of 493 participants that met the criteria for inclusion. As the authors noted, "only a few studies successfully blinded participants and therapists, due to the challenges associated with executing double-blind procedures in non-pharmacological studies."

After adjusting for publication bias, the meta-analysis of the fifteen studies found a large improvement in overall executive functioning.

The studies varied in which aspects of executive functioning were addressed. A meta-analysis of a subset of eleven studies encompassing 406 participants found a large improvement in inhibitory control. A meta-analysis of another subset, of eight studies with a total of 311 participants, found a large improvement in cognitive flexibility. Finally, a meta-analysis of a subset of five studies encompassing 198 participants found a small-to-medium improvement in working memory.

Nine studies involved acute (singular) exercise interventions lasting 5 to 30 minutes, while twelve studies involved chronic (regular) exercise interventions ranging from 6 to 12 weeks, with a total duration of 12 to 75 hours. The chronic exercise was more than twice as effective as acute exercise. The former resulted in large improvements in overall executive functioning, the latter in small-to-medium improvements.

No significant differences were found between aerobic exercises (such as running and swimming) and cognitively engaging exercises(such as table tennis and other ball games, and exergaming ... video games that are also a form of exercise, relying on technology that tracks body movements).

The authors concluded that "Chronic sessions of exercise interventions with moderate intensity should be incorporated as a treatment for children with ADHD to promote executive functions."

Meanwhile, a German study team (Seiffer et al. 2021) looked at the effects of regular, moderate-to-vigorous physical activity on ADHD symptoms in children and adolescents.

They found eleven studies meeting their criteria, with a combined total of 448 participants. A meta-analysis of all eleven studies found a small-to-moderate decline in ADHD symptoms. However, the three studies with blinded outcome assessors found a large and statistically highly significant decline in symptoms, whereas the eight studies with blinded outcome evaluators found only a small decline that was not statistically significant.

When compared with active controls using pharmacotherapy in a subgroup of two studies with 146 participants, pharmacotherapy held a small-to-moderate advantage that fell just short of statistical significance, most likely because of the relatively small sample size.

The authors concluded that moderate to vigorous physical activity (MVPA) "could serve as an alternative treatment for ADHD," but that additional randomized controlled trials "are necessary to increase the understanding of the effect regarding frequency, intensity, type of MVPA interventions, and differential effects on age groups."

Xiao Liang, Ru Li, Stephen H. S. Wong, Raymond K. W. Sum andCindy H. P. Sit, "The impact of exercise interventions concerning executivefunctions of children and adolescents with attention-deficit/ hyperactivedisorder: a systematic review and meta-analysis," International Journal of Behavioral Nutrition and Physical Activity(2021), 18:68, published online,https://doi.org/10.1186/s12966-021-01135-6.
Britta Seiffer, Martin Hautzinger, Rolf Ulrich, andSebastian Wolf, "The Efficacy of Physical Activity for Children with AttentionDeficit Hyperactivity Disorder: A Meta-Analysis of Randomized Controlled Trials," Journal of Attention Disorders (2021), published online, https://doi.org/10.1177/10870547211017982.

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Oppositional Defiant Disorder, Autism, and ADHD: New Research Examines the Connection

Oppositional Defiant Disorder (ODD)—a pattern of chronic irritability, anger, arguing, or defiance—is one of the most challenging behavioral conditions families and clinicians face. 

A new study involving 2,400 children ages 3–17 offers one of the clearest pictures yet. Using parent-reported data from the Pediatric Behavior Scale, researchers compared how often ODD appears in Autism spectrum disorder (ASD), ADHD-Combined presentation (ADHD-C), ADHD-Inattentive presentation (ADHD-I), and those with both ASD and ADHD.

Results

ADHD-Combined + ODD: The Highest-Risk Group

Children with ADHD-Combined presentation show both hyperactivity/impulsivity and inattention.  They had the highest ODD rates of any single diagnosis: 53% of kids with ADHD-Combined met criteria for ODD.

But when autism was added to ADHD-Combined, the prevalence jumped to 62%. This group also had the highest overall ODD scores, suggesting more severe or more impairing symptoms. 

This synergy matters: while autism alone increases ODD risk, the presence of ADHD-Combined is what pushes prevalence into the majority range. Other groups showed lower, but still significant, rates of ODD:

  • Autism + ADHD-Inattentive: 28%
  • Autism Only: 24%
  • ADHD-Inattentive Only: 14%

These findings echo what clinicians often see: children with inattentive ADHD, while struggling significantly with attention and learning, tend to show fewer behavioral conflict patterns than those with hyperactive/impulsive symptoms.

It is important to note that ODD is considered to have two main components. Across all diagnostic groups, ODD consistently broke down into these two components: either Irritable/Angry (emotion-based) or Oppositional/Defiant (behavior-based). But the balance between these components differed depending on diagnosis. Notably, Autism + ADHD-Combined showed higher levels of the irritable/angry component than ADHD-Combined alone. The oppositional/defiant component did not differ much between groups. This suggests that autism elevates the emotional side of ODD more than the behavioral side, which is important for clinicians to note before tailoring interventions.

Understanding ADHD , ASD, & Comorbidity:

The study notes that autism, ADHD, and ODD often cluster together, with 55–90% comorbidity in some combinations.

As the authors explain, The high co-occurrence of ADHD-Combined in autism (80% in our study) largely explains the high prevalence of ODD in autism.” 

Clinical Implications: Why This Study Matters

The researchers point to a straightforward recommendation: clinicians shouldn’t evaluate these conditions in isolation. A child referred for autism concerns might also be struggling with ADHD. A child referred for ADHD might have undiagnosed ODD. And ignoring one disorder can undermine treatment for the others.

Evidence-based interventions (behavioral therapy, parent training, school supports, and/or medication) can reduce symptoms across all three diagnoses while improving long-term outcomes, including overall quality of life.

November 21, 2025

What Sleep Patterns Reveal About Mental Health: A Look at New Research

Background:

Sleep is more than simple rest. When discussing sleep, we tend to focus on the quantity rather than the quality,  how many hours of sleep we get versus the quality or depth of sleep. Duration is an important part of the picture, but understanding the stages of sleep and how certain mental health disorders affect those stages is a crucial part of the discussion. 

Sleep is an active mental process where the brain goes through distinct phases of complex electrical rhythms. These phases can be broken down into non-rapid eye movement (NREM) and rapid eye movement (REM). The non-rapid eye movement phase consists of three stages of the four stages of sleep, referred to as N1, N2(light sleep), and N3(deep sleep). N4 is the REM phase, during which time vivid dreaming typically occurs. 

Two of the most important measurable brain rhythms occur during non-rapid eye movement (NREM) sleep. These electrical rhythms are referred to as slow waves and sleep spindles. Slow waves reflect deep, restorative sleep, while spindles are brief bursts of brain activity that support memory and learning.

The Study: 

A new research review has compiled data on how these sleep oscillations differ across psychiatric conditions. The findings suggest that subtle changes in nightly brain rhythms may hold important clues about a range of disorders, from ADHD to schizophrenia.

The Results:

ADHD: Higher Spindle Activity, Mixed Slow-Wave Findings

People with ADHD showed increased slow-spindle activity, meaning those brief bursts of NREM activity were more frequent or stronger than in people without ADHD. Why this happens isn’t fully understood, but it may reflect differences in how the ADHD brain organizes information during sleep. Evidence for slow-wave abnormalities was mixed, suggesting that deep sleep disruption is not a consistent hallmark of ADHD.

Autism: Inconsistent Patterns, but Some Signs of Lower Sleep Amplitude

Among individuals with autism spectrum disorder (ASD), results were less consistent. However, some studies pointed to lower “spindle chirp” (the subtle shift in spindle frequency over time) and reduced slow-wave amplitude. Lower amplitude suggests that the brain’s deep-sleep signals may be weaker or less synchronized. Researchers are still working to understand how these patterns relate to sensory processing, learning differences, or daytime behavior.

Depression: Lower Slow-Wave and Spindle Measures—Especially With Medication

People with depression tended to show reduced slow-wave activity and fewer or weaker sleep spindles, but this pattern appeared most strongly in patients taking antidepressant medications. Since antidepressants can influence sleep architecture, researchers are careful not to overinterpret the changes.  Nevertheless, these changes raise interesting questions about how both depression and its treatments shape the sleeping brain.

PTSD: Higher Spindle Frequency Tied to Symptoms

In post-traumatic stress disorder (PTSD), the trend moved in the opposite direction. Patients showed higher spindle frequency and activity, and these changes were linked to symptom severity which suggests that the brain may be “overactive” during sleep in ways that relate to hyperarousal or intrusive memories. This strengthens the idea that sleep physiology plays a role in how traumatic memories are processed.

Psychotic Disorders: The Most Consistent Sleep Signature

The clearest and most reliable findings emerged in psychotic disorders, including schizophrenia. Across multiple studies, individuals showed: Lower spindle density (fewer spindles overall), reduced spindle amplitude and duration, correlations with symptom severity, and cognitive deficits.

Lower slow-wave activity also appeared, especially in the early phases of illness. These results echo earlier research suggesting that sleep spindles, which are generated by thalamocortical circuits, might offer a window into the neural disruptions that underlie psychosis.

The Take-Away:

The review concludes with a key message: While sleep disturbances are clearly present across psychiatric conditions, the field needs larger, better-standardized, and more longitudinal studies. With more consistent methods and longer follow-ups, researchers may be able to determine whether these oscillations can serve as reliable biomarkers or future treatment targets.

For now, the take-home message is that the effects of these mental health disorders on sleep are real and measurable.

Population Study Links ADHD Medication with Reduced Criminality, Suicides, Automotive Crashes, Substance Abuse

Many studies have shown that ADHD is associated with increased risks of suicidal behavior, substance misuse, injuries, and criminality. As we often discuss in our blogs, treatments for ADHD include medication and non-medication options, such as CBT (Cognitive Behavioral Therapy). While non-drug approaches are often used for young children or mild cases of ADHD, medications – both stimulants and non-stimulants – are common for adolescents and adults. 

Global prescriptions for ADHD drugs have risen significantly in recent years, raising questions about their safety and effectiveness. Randomized controlled trials have demonstrated that medication can help reduce the core symptoms of ADHD. However, research from these trials still offers limited or inconclusive insights into wider and more significant clinical outcomes, such as suicidal behavior and substance use disorder.

An international study team conducted a nationwide population study using the Swedish national registers. Sweden has a single-payer national health insurance system, which covers nearly every resident, enabling such studies. The researchers examined all Swedish residents aged 6 to 64 who received their first ADHD diagnosis between 2007 and 2018. Analyses of criminal behavior and transport accidents focused on a subgroup aged 15 to 64, since individuals in Sweden must be at least 15 years old to be legally accountable for crimes or to drive.

The team controlled for confounding factors, including demographics (age at ADHD diagnosis, calendar year, sex, country of birth, highest education (using parental education for those under 25), psychiatric and physical diagnoses, dispensations of psychotropic drugs, and health care use (outpatient visits and hospital admissions for both psychiatric and non-psychiatric reasons).

Time-varying covariates from the previous month covered diagnoses, medication dispensations, and healthcare use. During the study, ADHD treatments licensed in Sweden included amphetamine, atomoxetine, dexamphetamine, guanfacine, lisdexamphetamine, and methylphenidate.

After accounting for covariates, individuals diagnosed with ADHD who received medication treatment showed better outcomes than those who did not. Specifically:

-Suicidal behaviors dropped by roughly 15% in both first-time and recurrent cases.

-Initial criminal activity decreased by 13%, with repeated offences falling by 25%.

-Substance abuse initiation declined by 15%, while recurring substance abuse was reduced

by 25%.

-First automotive crashes were down 12%, and subsequent crashes fell by 16%.

There was no notable reduction in first-time accidental injuries, and only a marginally significant 4% decrease in repeated injuries.

The team concluded, “Drug treatment for ADHD was associated with beneficial effects in reducing the risks of suicidal behaviours, substance misuse, transport accidents, and criminality, but not accidental injuries when considering first event rate. The risk reductions were more pronounced for recurrent events, with reduced rates for all five outcomes.”