Seven New Meta-analyses Suggest Wide Range of Benefits from Exercise for Persons with ADHD

A team of Spanish researchers has published a systematic review of 16 studies with a total of 728 participants exploring the effects of physical exercise on children and adolescents with ADHD. Fourteen studies were judged to be of high quality, and two of medium quality.

Seven studies looked at the acute effects of exercise on eight to twelve-year-old youths with ADHD. Acute means that the effects were measured immediately after periods of exercise lasting up to 30 minutes. Five studies used treadmills and two used stationary bicycles, for periods of five to 30 minutes. Three studies "showed a significant increase in the speed of reaction and precision of response after an intervention of 20-30 min, but at moderate intensity (50-75%)." Another study, however, found no improvement in mathematical problem-solving after 25 minutes using a stationary bicycle at low (40-50%) or moderate intensity (65-75%). The three others found improvements in executive functioning, planning, and organization in children after 20- to 30-minute exercise sessions.

Nine studies examined longer-term effects, following regular exercise over many weeks. One reported that twenty consecutive weekly yoga sessions improved attention. Another found that moderate to vigorous physical activity (MVPA) led to improved behavior beginning in the third week, and improved motor, emotional and attentional control, by the end of five weeks. A third study reported that eight weeks of starting the school day with 30 minutes of physical activity led to improvement in Connor's ADHD scores, oppositional scores, and response inhibition. Another study found that twelve weeks of aerobic activity led to declines in bad mood and inattention. Yet another reported that thrice-weekly 45-minute sessions of MVPA over ten weeks improved not only muscle strength and motor skills, but also attention, response inhibition, and information processing.

Two seventy-minute table tennis per week over twelve weeks improved executive functioning and planning, in addition to locomotor and object control skills.

Two studies found a significant increase in brain activity. One involved two hour-long sessions of rowing per week for eight weeks, the other three 90-minute land-based sessions per week for six weeks. Both studies measured higher activation of the right frontal and right temporal lobes in children, and lower theta/alpha ratios in male adolescents.

All 16 studies found positive effects on cognition. Five of the nine longer-term studies found positive effects on behavior. No study found any negative effects. The authors of the review concluded that physical activity "improves executive functions, increases attention, contributes to greater planning capacity and processing speed and working memory, improves the behavior of students with ADHD in the learning context, and consequently improves academic performance." Although the data are limited by a lack of appropriate controls, they suggest that, in addition to the well-known positive effects of physical activity, one may expect to see improvements in ADHD symptoms and associated features, especially for periods of sustained exercise.

Noting that "Growing evidence shows that moderate physical activity (PA) can improve psychological health through enhancement of neurotransmitter systems," and "PA may play a physiological role similar to stimulant medications by increasing dopamine and norepinephrine neurotransmitters, thereby alleviating the symptoms of ADHD," a Chinese team of researchers performed a comprehensive search of the peer-reviewed journal literature for studies exploring the effects of physical activity on ADHD symptoms.

They found nine before-after studies with a total of 232 participants, and fourteen two-group control studies with a total of 303 participants, that met the criteria for meta-analysis.

The meta-analysis of before-after studies found moderate reductions in inattention and moderate-to-strong reductions in hyperactivity/impulsivity. It also reported moderate reductions in emotional problems and small-to-moderate reductions in behavioral problems.

The effect was even stronger among unmediated participants. There was a very strong reduction in inattention and a strong reduction in hyperactivity/impulsivity.

The meta-analysis of two-group control studies found strong reductions in inattention, but no effect on hyperactivity/impulsivity. It also found no significant effect on emotional and behavioral problems.

There was no sign of publication bias in any of the meta-analyses.

The authors concluded, "Our results suggest that PA intervention could improve ADHD-related symptoms, especially inattention symptoms. However, due to a lot of confounders, such as age, gender, ADHD subtypes, the lack of rigorous double-blinded randomized-control studies, and the inconsistency of the PA program, our results still need to be interpreted with caution."

Myth:  ADHD medications "anesthetize" ADHD children.
 The idea here is that the drug treatment of ADHD is no more than a chemical straightjacket intended to control a child's behavior to be less bothersome to parents and teachers. After all, everyone knows that if you shoot up a person with tranquilizers, they will calm down.

Fact:  ADHD medications are neither anesthetics nor tranquilizers.
The truth of the matter is that most ADHD medications are stimulants. They don't anesthetize the brain; they stimulate it. By speeding up the transmission of dopamine signals in the brain, ADHD medications improve brain functioning, which in turn leads to an increased ability to pay attention and control behavior.  The non-stimulant medications improve signaling by norepinephrine. They also improve the brain's ability to process signals. They are not sedatives or anesthetics. When taking their medication, ADHD patients can focus and control their behavior to be more effective in school, work, and relationships.  They are not "drugged" into submission.

Myth: ADHD medications cause drug and alcohol abuse
We know from many long-term studies of ADHD children that when they reach adolescence and adulthood, they are at high risk for alcohol and drug use disorders. Because of this fact, some media reports have implied that their drug use was caused by treatment of their ADHD with stimulant medications.

Fact: ADHD medications do not cause drug and alcohol abuse
Some ADHD medications indeed use the same chemicals that are found in street drugs, such as amphetamine.  But there is a very big difference between these medications and street drugs. When street drugs are injected or snorted, they can lead to addiction, but when they are taken in pill form as prescribed by a doctor, they do not cause addiction. When my colleagues and I examined the world literature on this topic, we found that rather than causing drug and alcohol abuse, stimulant medicine protected ADHD children from these problems later in life. One study from researchers at Harvard University and the Massachusetts General Hospital found that the drug treatment of ADHD reduced the risk for illicit drug use by84 a percent. These findings make intuitive sense. These medicines reduce the symptoms of the disorder that lead to illicit drug use. For example, an impulsive ADHD teenager who acts without thinking is much more likely to use drugs than an ADHD teen whose symptoms are controlled by medical drug treatment. After we published our study, other work appeared. Some of these studies did not agree that ADHD medications protected ADHD people from drug abuse, but they did not find that they caused drug abuse.

Myth:  Psychological or behavioral therapies should be tried before medication.  
Many people are cautious about taking medications, and that caution is even stronger when parents consider treatment options for their children.  Because medications can have side effects, shouldn't people with ADHD try to talk therapy before taking medicine?

Fact:  Treatment guidelines suggest that medication is the first-line treatment.
The problem with trying talk or behavior therapy before medication is that medication works much better.  For ADHD adults, one type of talk therapy(cognitive behavioral therapy) is recommended, but only when the patient is also taking medication.  The multimodal treatment of ADHD (MTA) study examined this issue in ADHD children from several academic medical centers in the United States. That study found that treating ADHD with medication was better than treating it with behavior therapy. Importantly, behavior therapy plus medication was no more effective than medication alone. That is why treatment guidelines from the American Academy of Pediatrics and the American Academy of Children and Adolescents recommend medicine as a first-line treatment for ADHD, except for preschool children. ADHD medications indeed have side effects, but these are usually mild and typically do not interfere with treatment.  And don't forget about the risks that a patient faces when they do not use medications for ADHD.  These untreated patients are at risk for worsening ADHD symptoms and complications.

Myth: Brain abnormalities of ADHD patients are caused by psychiatric medications
A large scientific literature shows that ADHD people have subtle problems with the structure and function of their brains.  Scientists believe that these problems are the cause of ADHD symptoms. Critics of ADHD claim that these brain problems are caused by the medications used to treat ADHD.  Who is right?

Fact: Brain abnormalities are found in never medicated ADHD patients.
Alan Zametkin, a scientist at the US National Institute of Mental Health, was the first to show brain abnormalities in ADHD patients who had never been treated for their ADHD.  He found that some parts of the brains of ADHD patients were underactive. His findings could not be due to medication because the patients had never been medicated. Since his study, many other researchers have used neuroimaging to examine the brains of ADHD patients. This work confirmed Dr. Zametkin’s observation of abnormal brain findings in unmediated patients. Reviews of the brain imaging literature have concluded that the brain abnormalities seen in ADHD cannot be attributed to ADHD medications.