Stimulants work on the part of the brain that helps people pay attention, control impulses, control motor behavior, and stay organized. Studies have found these ADHD meds to be effective in up to 80 percent of people with ADHD. Because these medications that help with ADHD symptoms act on the central nervous system, your child may also experience side effects such as anxiousness or problems sleeping when he starts ADHD treatment, says Carla Allan, PhD, co-director of the ADHD Specialty Clinic at Children’s Mercy Hospitals and Clinics in Kansas City, Mo. However, when the drugs are prescribed properly (starting a child with a low dose that’s increased if needed), side effects shouldn’t be much of a problem, Allan says. And while you may notice some of these side effects during the first one to two weeks of taking the medication, they should go away after two weeks, she says. If they don’t, your child may need a smaller dose. 10 Potential ADHD Treatment Side Effects Here are 10 side effects associated with stimulant ADHD meds and what you can do about them:

  1. Anxiety. Your child may feel anxious for the first day or two after starting the stimulant, Allan says, but this is a side effect that should go away.
  2. An upset stomach. Thankfully, an upset stomach that’s caused by the medication usually doesn’t last long, Allan says. Eating a high protein breakfast can help, but you may also want to talk to your child’s doctor about treating the stomach upset with another medication, she says.
  3. Difficulty sleeping. Some kids will have a harder time sleeping when they first begin stimulants, though others are better able to organize and get themselves to bed on time. “I’ve seen instances of both of those things happening,” Allan says. If your child is having trouble sleeping, switching to a shorter-acting medication (one that wears off more quickly than a long-acting one) can help to get your child to sleep on time.
  4. Daytime drowsiness. In addition to having trouble falling asleep, stimulants may also cause your child to spend more time in non-REM (rapid eye movement) sleep, which is a lighter stage of sleep. That can lead to drowsiness during the day.
  5. Mood changes. Initially, you may notice your child being more irritable on the new medication, Allan says. This has been the biggest side effect for Kara Wiemert’s 16-year-old sister, who has been taking ADHD meds since she was about 7 years old. “Before she pretty much had one mood of constantly happy and overly energetic,” Boston-based Wiemert says. “She now has mood swings to the extreme where she’s almost unbearable to be around.” Unfortunately, the mood swings haven’t gone away for her sister, but her family has learned to be more understanding. Wiemert also has noticed that her sister is less moody since she found other friends with ADHD who she can relate to.
  6. Rebounding effects. Around the time that the medication wears off, children can become more irritable and the ADHD symptoms may return, which is called a rebounding effect. The timing of this depends on whether your child takes a short-acting stimulant (which lasts about four hours) or a long-acting medication (which lasts 6 to 12 hours). Doctors tend to prescribe shorter-acting stimulants to younger children who don’t have a lot of homework to do in the evenings after school, Allan says. Older kids who still need to focus well into the evening may be prescribed longer-acting medications.
  7. Headaches. It’s common to experience headaches at the beginning of a new stimulant medication, but you can treat the headaches with an over-the-counter pain reliever.
  8. Decreased appetite. This is a side effect that goes away for some kids, but lasts longer for others, Allan says. Here’s how you can get your child the nutrition he needs: Give him a big, healthy breakfast in the morning, followed by his stimulant medication. He may not eat much for lunch, but later, when the medication wears off, give him the opportunity to snack on calorie-dense foods like a milkshake with a supplement drink added to it, such as Carnation Instant Breakfast, Allan says.
  9. Tics. About 9 percent of children who take stimulants experience tics or movements in which they jerk their body. This side effect tends to wear off, but changing your child’s dose may help in the meantime. Ask your doctor for guidance.
  10. Changes in heart rate and blood pressure. ADHD meds haven’t been found to cause heart conditions, but studies show that kids who have heart conditions tend to be more likely to have ADHD. ADHD medications can cause either an increase or a decrease in heart rate and blood pressure. For this reason, the American Heart Association has recommended that children should be tested before starting the drug to be sure they don’t have a heart condition. Stimulants, especially when combined with behavioral therapies, can be very effective at treating ADHD symptoms. As a parent, keeping careful track of any side effects and letting your doctor know if they’ve gotten better or worse while your child is taking the medication, will help minimize these symptoms as you see your child improve.