Can Brain Stimulation Combined with Cognitive Training Help Teens with ADHD?

What you need to know

• This study tested whether combining brain stimulation with cognitive training could improve ADHD symptoms and cognitive skills in adolescent boys.
• The brain stimulation (tDCS) did not lead to improvements in ADHD symptoms or cognitive performance compared to a sham treatment.
• Some temporary negative effects on mood, sleep, and appetite were reported after the real brain stimulation.
• More research is needed to determine if this type of combined treatment could be helpful for ADHD when used differently.

Background on ADHD and Potential Treatments

Attention-deficit/hyperactivity disorder (ADHD) is a common condition that involves ongoing problems with attention, hyperactivity, and impulsive behavior. People with ADHD often have difficulties with skills like focusing, organizing tasks, and controlling impulses.

While medications can be helpful for managing ADHD symptoms, they don’t work for everyone and can have side effects. Researchers are interested in developing new treatment options that could help improve brain function and reduce symptoms without medication.

One area of research involves using weak electrical currents to stimulate specific brain regions, a technique called transcranial direct current stimulation (tDCS). Some early studies suggested tDCS might help improve attention and reduce impulsivity when applied to certain parts of the brain. Researchers wondered if combining tDCS with cognitive training exercises could lead to even greater improvements for people with ADHD.

What Did This Study Do?

This study recruited 50 boys aged 10-18 who had been diagnosed with ADHD. The boys were randomly divided into two groups:

1. Active tDCS group: Received real brain stimulation plus cognitive training
2. Sham group: Received fake brain stimulation plus cognitive training

The brain stimulation targeted an area called the right inferior frontal cortex, which is involved in skills like impulse control that are often impaired in ADHD.

For 3 weeks (15 weekdays total), participants came to the lab each day for a 20-minute session. During the session, they played cognitive training games on a computer or tablet while receiving either real or fake brain stimulation. The cognitive games were designed to exercise skills like attention, memory, and impulse control.

Neither the participants nor the researchers running the daily sessions knew which type of stimulation each person was receiving. This “double-blind” approach helps prevent expectations from influencing the results.

The researchers assessed ADHD symptoms, cognitive skills, and potential side effects at three time points:

1. Before starting treatment (baseline)
2. Right after finishing the 3 weeks of sessions
3. 6 months after treatment ended

They compared the results between the two groups to see if the real brain stimulation led to any additional benefits beyond just doing the cognitive training alone.

Key Findings

No Improvement in ADHD Symptoms or Cognitive Skills

Contrary to what the researchers expected, the group receiving real brain stimulation did not show greater improvements in ADHD symptoms or cognitive test performance compared to the sham group. In fact, right after treatment, the active tDCS group had slightly higher symptom ratings on some ADHD scales.

Both groups showed some improvements in symptoms and cognitive skills over time. However, these changes were likely due to the cognitive training exercises, which both groups completed, or possibly just from repeatedly practicing the assessment tasks.

Temporary Negative Effects

The active tDCS group reported some increased negative effects right after finishing treatment, including:

• Irritability
• Decreased appetite
• Difficulty falling asleep

These effects were temporary and not considered serious, but they suggest the brain stimulation was having some impact even if it wasn’t leading to symptom improvements.

Possible Longer-Term Effects?

Interestingly, at the 6-month follow-up, the active tDCS group showed slightly lower scores for hyperactivity/impulsivity symptoms compared to the sham group. While this finding needs to be confirmed by other studies, it hints at the possibility of some delayed positive effects from the stimulation.

Why Didn’t It Work As Expected?

The researchers proposed a few potential reasons why the brain stimulation didn’t lead to the improvements they anticipated:

1. The stimulation may have been too strong for the adolescent brain, potentially disrupting normal activity instead of enhancing it.

2. Stimulating one specific brain area may have unintentionally affected neighboring regions in unhelpful ways.

3. The participants in the active tDCS group happened to be slightly younger on average and had more severe symptoms at the start of the study. This may have made it harder for them to benefit from the treatment.

4. The number or timing of stimulation sessions may not have been optimal. It’s possible that fewer sessions or a different schedule could have produced better results.

Conclusions

• This well-designed study found that combining brain stimulation with cognitive training did not lead to improvements in ADHD symptoms or cognitive skills in adolescent boys.

• The treatment appeared safe overall, but did cause some temporary negative effects on mood, sleep, and appetite.

• While disappointing, these results are important because they show that this specific protocol is likely not an effective treatment option for ADHD.

• More research is still needed to determine if brain stimulation could be helpful for ADHD when applied differently (e.g., to different brain regions, at different intensities, or for different lengths of time).

• For now, established treatments like medication and behavioral therapy remain the best options for managing ADHD symptoms in most cases.

This study highlights the complexity of developing new treatments for ADHD and other brain-based conditions. Even when a treatment seems promising based on early research, rigorous testing is crucial to determine if it actually provides benefits in real-world use. While this particular approach wasn’t successful, it contributes valuable knowledge that will help guide future treatment development efforts for ADHD.