Stimulants are the most common treatment for attention deficit hyperactivity disorder (ADHD). The ADHD “zombie effect” refers to one of their less frequent side effects. It involves being unnaturally quiet, which can make children’s behavior appear different from what is typical for them.

When this effect occurs, it may indicate that the child’s medication dose is too high. A parent or caregiver needs to contact a doctor quickly if this happens.

This article discusses the ADHD zombie effect, including symptoms, when to contact a doctor, causes, and treatment. It also examines the effectiveness of medications for ADHD and how to manage the condition.

person in the parkShare on Pinterest
Annie Otzen/Getty Images

The ADHD zombie effect involves feeling zoned out, lifeless, and drugged. According to an older 2017 study, this is a frequent reason why children and teenagers with the condition stop taking medication.

It is one of the less frequent side effects of the medication and a sign that a person’s dose is too high.

Learn more about ADHD.

Aside from a zoned-out feeling, symptoms relating to the zombie effect may include:

  • never getting hungry
  • not feeling quite like oneself
  • frequent trouble with sleeping well
  • feeling irritable and wired most of the day

Other symptoms may involve being unnaturally quiet and overfocused, which is a stark difference from typical ADHD behavior. Additionally, symptoms may include having a tic or manifesting repetitive movements, such as picking the skin.

A parent or caregiver needs to let the child’s doctor know quickly if their child appears to be experiencing a zombie effect. Doctors can modify the dose until they determine a suitable amount. It can take some trial and error before finding the right balance between benefits and side effects.

A small subset of children with ADHD may experience such symptoms with stimulant medications even if they take an optimal dose. When this happens, these symptoms typically present as soon as they begin taking them and disappear immediately after a doctor discontinues the medication.

In such cases, a child may be able to tolerate another type of stimulant. If not, a nonstimulant drug may serve as an alternative.

Because it can be difficult for people to remember all the side effects, experts recommend keeping a medication log or journal. This offers a means of recording daily side effects and enables a doctor to note patterns.

The causes of the zombie effect stem from how ADHD medications affect the brain. Stimulants — the most common medications that doctors prescribe for ADHD — increase levels of two neurotransmitters: dopamine and norepinephrine. Neurotransmitters are chemicals that carry messages from a nerve cell to a target cell. While neurotransmitters have different functions, dopamine and norepinephrine are important in promoting mental focus and attention.

However, stimulants, like all medications, are only therapeutic within a certain range. If a person takes too small a dose, it is ineffective, but if they take too high a dose, it can have negative effects. When dopamine and norepinephrine are too high, they can stress the brain, which may result in the zombie effect, along with other harmful reactions.

One treatment method involves lowering the dose of ADHD medications. When this does not eliminate the zombie effect, a doctor may switch medications to a different stimulant or a nonstimulant.

Stimulant ADHD medications

The two types of stimulant medications are those deriving from methylphenidate, such as Ritalin, and those deriving from dextroamphetamine, such as Adderall.

Some children may respond differently to the two types. Some may also respond differently to a change in the release formula they take. A release formula refers to the speed at which the medication enters the bloodstream. Long-acting formulas release the medication slowly, while short-acting formulas release it quickly.

Learn more about Ritalin and Adderall.

Nonstimulant ADHD medications

There are two types of nonstimulant medications, one of which involves clonidine (Catapress) and guanfacine (Tenex). These belong to a class of drugs that researchers developed to lower high blood pressure.

The other type of nonstimulant medication for ADHD is atomoxetine (Strattera), which increases levels of norepinephrine. There has also been the introduction of a new nonstimulant known as viloxazine (Qelbree).

Stimulants reduce symptoms in 70 to 80% of children with ADHD. In fact, the medications decrease them by 40–50% and result in noticeable improvements in school performance and interactions with family and peers.

Within this group of children, 50% respond equally well to the two types of stimulants. Among the other 50%, half respond better to methylphenidate and the other half respond better to amphetamine.

Doctors consider the nonstimulant options less effective.

The Centers for Disease Control and Prevention (CDC) provide the below tips for managing ADHD:

  • Reduce distractions: Provide a clean workspace for homework, limit noise, and turn off the TV.
  • Maintain a set schedule: Try to follow a daily routine that includes everything from wake-up time to bedtime.
  • Use clear, brief directions: When a child needs to do something, tell them in a clear, specific way.
  • Establish goals and reward achievement: List goals on a chart and track positive behaviors. Respond to the achievement of small, realistic steps with praise and other rewards.
  • Create positive opportunities: Identify what a child does well and encourage them to engage in it.
  • Limit choices: Choices that are too broad can overwhelm a child. Offer only a few options, such as choosing between two meals.
  • Help the child plan: Break down a complex activity into short, simple steps.
  • Avoid negative discipline: Instead of shouting, remove privileges or use timeouts when behavior is inappropriate.
  • Promote a healthy lifestyle: To help prevent symptoms from worsening, encourage regular physical activity, provide nutritious food, and foster habits that will lead to sufficient sleep.

The ADHD zombie effect is a drugged, zoned-out feeling where a child is unnaturally quiet. It is one of the side effects of stimulant medications and can indicate that a dose is too high.

Some children experience these symptoms even when they are taking an optimal dose. When this happens, a doctor may change their medication to another stimulant or try a nonstimulant medication.

Stimulants often reduce ADHD symptoms, but various management approaches may also help, such as maintaining a set schedule.

Because a change in dose or medication is sometimes necessary, a parent or caregiver needs to report zombie-like symptoms to a doctor promptly.