What to Expect from ADHD Medication Side Effects

Whenever your child is prescribed a new medication, it’s very normal to worry about side-effects. That goes double when the medication is for something like ADHD, some of which are controlled substances.

Here I’ll try to walk you through the common (and manageable) side-effects and what to do about them, and alert you to the rare (but potentially serious ones) that you’ll absolutely need to talk to your health-care provider about.

Before we start, it’s important to keep in mind that untreated ADHD has real risks, including higher rates of accidents, self-harm, and substance problems. So you’re not choosing between side-effects vs none, but balancing side-effects with the harms of non-treatment.

The everyday stuff: appetite, sleep, and tummy troubles

These are the side effects you're most likely to hit, and the good news is they're usually mild and dose-related, meaning they often get better when the dose is reduced.

A large review of methylphenidate (the medication in Ritalin and Concerta) in children¹ considered tens of thousands of kids and found that the most commonly reported, non-serious side effects were:

Side effect	Approximate frequency
Decreased appetite	~31% (so 3 out of every 10 kids)
Trouble falling asleep	~18% (up to 2 our of every 10 kids)
Headache	~14% (between 1-2 out of every 10 kids)
Abdominal (tummy) pain	~11% (around 1 out of every 10 kids)

Appetite and eating

The highest rate of reported issues is around decreased appetite. That’s not a surprise as stimulants often dull hunger signals, but the appetite usually comes back strongly as they wear off.

The common pattern is a child who picks at lunch (when there’s still a lot of the medication in their body) but is starving at dinner. An occasional smaller lunch isn’t a problem, but a sustained reduction in intake can eventually affect weight and growth.

A few strategies that help:

• Offer a big, protein-rich breakfast before the medication kicks in.

• When appetite returns after the dose wears off, give them a substantial dinner.

• Make nutrient- and calorie-dense foods (nut butters, full-fat dairy, smoothies, avocado) available so that they can reach for them rather than filling up on unhealthy snacks.

• Pushing food when the medication is peaking usually just creates stress for everyone, so dont worry too much about the missed lunches unless they are falling off their growth chart.

  
  

If appetite suppression is significant or you notice your child losing weight, loop in your provider. They might want to adjust the dose, switch to a shorter-acting formulation, or consider changes to the timing. But these aren’t changes to make on your own.

Sleep

Compared to no medication, methylphenidate roughly doubled to tripled the risk of sleep problems¹.

While the majority of children on this medication didn’t have problems, if you find that your child isn’t sleeping as well after starting it, you’re right to consider whether it’s a side-effect.

Sleep impacts are strongly dose-dependent. In a trial of children who started from a base of not taking any stimulant medications, parent-reported sleep problems generally climbed as the dose increased from about 8% on placebo, to 18% on a low dose, 15% on a medium dose (a step down!), and hitting 25% on the highest dose².

If your child is experiencing issues with sleep, talk to your provider about timing (giving the dose earlier in the day), trying a shorter-acting formulation, or nudging the dose down.

Headaches

ADHD medication can cause headaches (see the 14% number in the table above). Some children get a headache while the medication is at full strength, some as it wears off in the afternoon.

Headaches caused by ADHD medication tend to be mild and there’s a fair chance that they’ll decrease after the first week or two.

Two things to check before directly blaming the medication: your child may simply be under-eating or under-drinking because the medication suppresses appetite, and this itself can trigger headaches.

If you’ve waited a couple of weeks, and checked for dehydration etc, then track the timing of the headaches to see whether it’s a peak-dose or wearing-off effect, then consult with your child’s health-care provider. Don't use over-the-counter painkillers as a long-term workaround without checking first.

If headaches are frequent, severe, or persistent, or if they come with vision changes, vomiting, or don't respond to the basics, don’t wait! Contact your child's healthcare provider immediately.

Abdominal pain

Like headaches, this is usually mild and often settles within the first couple of weeks as your child adjusts. It tends to hit when the medication is at full strength, especially on an empty stomach.

Some things to try:

• With your provider’s knowledge, try taking the dose alongside breakfast. (But keep in mind that acidic foods and drinks, like fruit juice, energy drinks, or sports drinks like Gatorade; and vitamin C, negatively impact absorption of amphetamine-based meds (eg Vyvanse, Adderall). Grapefruit is a problem too, including with methylphenidates. This is why you need to keep your provider in the loop.) 

• Even a small snack at low-appetite times can ease the discomfort.

If the pain is severe, persistent, or comes with vomiting, weight loss, or changes in bathroom habits, don’t wait. These are signs that your child’s health-care provider should know about.

Let's talk cardiovascular effects

Stimulants are sympathomimetic, which is a fancy way of saying they bump up heart rate and blood pressure a little. A comprehensive systematic review found that stimulants can cause a small rise in blood pressure and heart rate but found no notable serious cardiovascular events³.

For the longer-term picture, a very large Swedish study⁴ found that long-term use was associated with a higher risk of hypertension and arterial disease, but not with arrhythmias, heart failure, ischemic heart disease, blood clots, or stroke. 

A separate study in adults did flag a small, dose-related increase in stroke and heart failure risk over ten years, but no increased risk of heart attack⁵.

The takeaway: for the vast majority of children with healthy hearts, stimulants are well tolerated. This is why your health-care provider asks about any family history of heart problems and may check blood pressure and heart rate at visits. Tell them if there's any history of structural heart disease, fainting, or sudden cardiac death in the family.

But, otherwise, this is a topic on which we have to balance a tiny risk of problems with the risk of problems from not-treating and, in general, the balance favors treatment.

The rare one parents should know about: psychosis

Psychosis is where a person loses some contact with reality: experiencing the world differently from those around them. We’re talking about hallucinations (perceiving things that aren’t real) and delusions (strongly believing things that aren’t real).

In a large study of over 220,000 teens and young adults new-onset psychosis occurred in roughly 1 in 660 patients taking stimulants⁶. So it is genuinely uncommon.

The class of medication matters. The risk was about twice as high (0.21%) with amphetamines (e.g. Adderall, Vyvanse) as with methylphenidate (e.g. Ritalin, Concerta) at 0.10%⁶. This is expected: amphetamines trigger dopamine release from neurons directly, but methylphenidate mainly blocks reuptake, so amphetamines produce a larger surge⁷.

If there's a family history of psychosis, bipolar disorder, or schizophrenia, this is worth a specific conversation with your prescriber about starting with methylphenidate rather than an amphetamine. Watch for any new changes in thinking, hearing or seeing things that aren't there, or unusual suspiciousness your child may be experiencing, and report them promptly.

What if my child is on a non-stimulant?

Non-stimulants like atomoxetine (Strattera) are a common alternative. Atomoxetine carries a boxed warning for suicidal thinking in children and teens.

A pooled analysis of 14 trials (2,208 kids) found suicidal ideation in 0.37% of children on atomoxetine versus 0% on placebo⁸. The researchers estimated you'd need to treat about 227 children to see one extra event. That’s in contrast to a number-needed-to-treat of just 5 for the medication to actually help ADHD symptoms⁸.

A few important pieces of context:

• No completed suicides occurred in these trials⁸.

• Every case of suicidal ideation happened in children 12 and younger, and the adult studies showed no increased risk⁹. (There was one attempted suicide without reported ideation in an older child.)

• Head-to-head, there was no difference in risk between atomoxetine and methylphenidate¹⁰.

  
  

This isn't a reason to avoid non-stimulants, but it is a reason to keep a close eye out, especially in the first few weeks and in younger children, and to keep an open line with your provider about your child's mood.

A bottom line

Here's the summary I'd want as a parent:

• The common side effects (appetite, sleep, headaches, tummy aches) are usually mild and adjustable.

• The serious side effects are rare, and some of them (like psychosis risk) can be reduced by which medication you choose.

• Methylphenidate-class medications tend to have a gentler risk profile for the rarest serious effects than amphetamines, which is useful if your family has relevant history.

• The risks of medication should always be weighed against the very real risks of leaving ADHD untreated.

  
  

Loop in your child's healthcare provider for anything new or concerning, and especially for: chest pain, fainting, a racing or irregular heartbeat, new or worsening mood changes, or any signs of disordered thinking.

This site is for general informational purposes only and does not constitute the giving of medical advice. The contents do not constitute the practice of medicine, nursing, or other professional health care services. No provider–patient relationship is formed. Please consult with your child's healthcare provider when considering or adjusting medication for children.

References

¹ Storebø OJ, et al. Methylphenidate for ADHD in children and adolescents — assessment of adverse events in non-randomised studies. Cochrane review. https://pmc.ncbi.nlm.nih.gov/articles/PMC6494554/

² Becker SP, et al. Effects of Methylphenidate on Sleep Functioning in Children with ADHD. https://pmc.ncbi.nlm.nih.gov/articles/PMC4887346/

³ Adverse Effects of Stimulant Interventions for ADHD: A Comprehensive Systematic Review. Cureus, 2023. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10601982/

⁴ Zhang L, et al. ADHD Medications and Long-Term Risk of Cardiovascular Diseases. JAMA Psychiatry. 2024;81(2):178-187. https://pmc.ncbi.nlm.nih.gov/articles/PMC10851097/

⁵ Holt A, et al. Long-Term Cardiovascular Risk Associated With Treatment of ADHD in Adults. J Am Coll Cardiol. 2024;83:1870-1882. https://www.acc.org/latest-in-cardiology/journal-scans/2024/05/09/13/35/long-term-cardiovascular-risk

⁶ Moran LV, et al. Psychosis with Methylphenidate or Amphetamine in Patients with ADHD. N Engl J Med. 2019;380(12):1128-1138. https://www.nejm.org/doi/full/10.1056/NEJMoa1813751

⁷ Faraone SV. The pharmacology of amphetamine and methylphenidate. Neurosci Biobehav Rev. 2018;87:255–270. PMC8063758. https://pmc.ncbi.nlm.nih.gov/articles/PMC8063758/.

⁸ Bangs ME, et al. Meta-analysis of suicide-related behavior events in patients treated with atomoxetine. J Am Acad Child Adolesc Psychiatry. 2008;47(2):209–218. PMID: 18176331. https://www.jaacap.org/article/S0890-8567(09)62292-9/abstract

⁹ Meta-analysis of suicide-related behavior or ideation in child, adolescent, and adult patients treated with atomoxetine. https://pubmed.ncbi.nlm.nih.gov/25019647/

¹⁰ Suicide related events and ADHD treatments in children and adolescents: a meta-analysis of atomoxetine and methylphenidate comparator clinical trials. https://pmc.ncbi.nlm.nih.gov/articles/PMC3691607/