How do ADHD medications work?

The degree of response to medication varies individually and some do not respond to stimulant medications. For a visual example of the effect of medication on one child, the links below are examples of one child’s handwriting:

Please note: This is only one child’s experience. Many children respond as well or better, but not all.


Adderall, Ritalin, Metadate, Methylin, Daytrana, Concerta, Dexedrine, Focalin, Quillivant XR and Vyvance are the stimulant medications currently on the market.


Stattera, or atomoxetine HCl has been available since January 2003. This is a non-stimulant, non-controlled substance medication. Straterra works on a different neurotransmitter compared to the stimulants that increase dopamin activity. Straterra is a selective norepinephrine reuptake inhibitor, meaning it increases the norepinephrine activity. Straterra is available in 5mg, 10mg, 18mg, 25mg, 40mg, 60mg, 80mg and 100mg capsules. The target dose is 1.2mg/kg in a single daily dose, but should be initiated at 0.5mg/kg to prevent side effects. In some patients (kids over 70kg body weight or adults), the dose was pushed up to a maximum of 100mg per day in a single daily dose or evenly distributed in a morning and late evening dose. If drowsiness occurs, the entire dose may be given at night.

Side effects may include allergic reactions (rare), weight loss, mild temporary growth retardation, hypertension and rapid heart rate, orthostatic hypotension (feeling dizzy when getting up from sitting due to a fall in blood pressure), urinary retention, dry mouth, abdominal pain3, irritability, constipation, nausea, sleeping difficulties, erectile and ejaculatory disturbances. Strattera is a milder medication with less dramatic effects compared to the fast acting stimulant medications. Yet, for some individuals who are unable to tolerate stimulant medications, Strattera may be an excellent alternative. These are, for the most part, individuals with anxiety disorders, nervous tic disorders, obsessive compulsive disorder or some patients with autism or other milder degrees of Pervasive Developmental Disorders (PDD’s) who are unable to tolerate stimulant medications. Strattera may take a longer time time to exert its functions, usually 1-2 weeks. On some occasions, Strattera may be added to stimulant medications in order to enhance their effect.


Adderall, an excellent first line medication for AD/HD. It is safe, effective, long acting (6-10 hours) and easily dosed. Unlike Ritalin, which is slow acting and comes in 20mg sustained release (SR) tablets that cannot be broken into smaller pieces, Adderall comes in 5, 7.5, 10, 12.5, 15, 20, and 30 mg tablets, all scorable to halves and quarters that make dosing much easier, enabling one to customize the dose specifically to the child’s needs, with great dosing flexibility.

Adderall XR or “extended release” stays in the system for 12 hours, covering the homeworks needs and some of the evening difficulties. The Adderall XR comes in a capsule form of 5mg, 10mg, 15mg, 20mg, 25mg, or 30mg. Another advantage is that this medication comes in sprinkle form that may be sprinkled on food, overcoming the need to swallow tablets or crush and ingest tablets that taste badly. A very effective course of action is to start with the short active Adderall, fine tune the dose based on the individual’s needs and then switch to the Adderal XR. Usually an additional 25-30% in total milligrams is required for this adjustment.

For example, a person who did best with 10mg of Adderall (short acting) will do very well with Adderall XR 15mg. This increases the duration of the same effect from 8-10 hours.


Concerta is a 12 hour (slow release) methylphenidate. This is the same substance as Ritalin, Meladate, Methylin, Daytrana and Quillivant XR. Concerta is an excellent alternative for Adderall, especially in the younger children who are irritable and cry easily as a side effect of Adderall or Dexedrine. Concerta must be swallowed and can’t be broken to small pieces since the mechanism of release is a small laser drilled hole at the pole of the capsule through which the medicine gets release during the course of the day.


Daytrana is the patch. It’s applied at the hip area and releases the same medicine as Concerta. The advantages include, no need to swallow, a full control on the duration of the activity (can be placed before the child wakes up or later during the day and may be taken off at any time.) Once taken off the effect continues for 3 hours. The disadvantages include a frequent rash, the child may take it off himself and some technical problems applying the patch reported by some people.

Quillivant XR

Quillivant XR is a liquid form of methylphenidate extended release that works well for 9-12 hours. It is an excellent first like medication since it provides the best available dosing flexibility with the measuring syringe, provided by the company.


Vyvance or Lisdexamfetamine, is a prodrug. Prodrug means that it has no effect at its given form, yet once ingested it converts into the active medication. In the Vyvance case, it converts to Dextroamphetamine and Amphetamine or Dexedrine. Dexedrine is a component of Adderall. Adderall is made of Dextroamphetamine and Amphetamine. The only difference between Vyvance and Dexedrine is the duration of action. Vyvance works 11-14 hours. Dexedrine works 4 hours and Dexedrine SR works 8 hours. Adderall is a more effective medication for most people and surprisingly, is very well tolerated.

Focalin and Focalin XR

Focalin is a component of Ritalin. The generic name is Detromethylphenidate (Dextro = Right) or the right side of the methylphenidate molecule. By splitting the Ritalin molecule and using just the right side of it, many of the side effects related to left side may be eliminated. This is an individual effect, but in some cases Focalin may eliminate the anxiety, tics, decreased appetite, OCD or sleeping problems that may occur in Ritalin.

To simplify the AD/HD stimulants medications understand: There are two groups. There are two groups. Ritalin-like and Adderall-like.

Group 1

  • Ritalin
  • Methylphenidate
  • Ritalin LA
  • Ritalin SR
  • Metadate
  • Metadate CD
  • Methylin
  • Methylin ER
  • Concerta
  • Daytrana
  • Quillivant XR
  • Focalin (Dextromethylphenidate)
  • Focalin XR

These are all the same. The only difference is the mechanism of release. Focalin is a portion (isomer) of Ritalin.

Group 2

  • Adderall
  • Aderall XR
  • Dexedrine
  • Dexedrine SR
  • Dextroamphetamine
  • Vyvance (once ingested)
  • ProCentra (4 hr liquid Dextroamphetamine)

Adderall and Adderall XR are Dexroamphetamin + Amphetamine, therefore, they will all have a similar effect. It must be noted, however, that for some unclear reason, some people will respond well to a particular medication, yet less effectively or poorly to the same preparation with a slightly different system.

In all, there are 12 Ritalin like medications and 5 Adderall like medications on the market. It may be confusing, but not if you think of it as just 2 drugs.

Treatment expectations

The treatment with stimulant medications is the backbone of treating AD/HD and the most important and effective measure of it. Parents have to be prepared for the fact that treatment may be prolonged. I like to compare treatment with stimulants and AD/HD in general, with placing glasses on eyes “which are out of focus.” This approach and understanding helps the child deal with his condition on a more acceptable level, not as a mental or psychiatric disorder, but more as a physical disability. I tell them, “Your attention span is out of focus. Taking Adderall in the morning is doing for your attention span what my glasses do for my eyes.” They are also told that “Without my glasses, despite having the ability to do well, I will not be able to read and I will most likely fail.” The same applies to AD/HD and medication. The parents should understand that fluctuating grades, a common aspect of AD/HD, may be similarly explained. A child who needs glasses, without them may do poorly, but when a lot of pressure mounts on him he will give it a great effort, placing his face close to the books, trying very hard to satisfy his parents, eventually succeeding to get a good grade because he has the mental ability. This effort, however, will be very difficult to maintain and a relapse to the lower grades is expected. The same thing may happen to children with AD/HD, resulting in their parents blaming them for being lazy, “Because you can do it, you have done it before.” This leads to increased frustration and more friction within the family.

Stimulants correct the underlying physiological abnormality causing AD/HD by increasing dopamine concentrations in the brain. The effect usually starts 1/2 hour after taking the medication. And with Adderall preparations, this lasts for an average of 8 or 12 hours. The effects must be clearly noticeable; a “questionable” response is unacceptable. Stimulants work in 70-80% of children with AD/HD. The effect of the stimulants may completely or partially correct the AD/HD. Once AD/HD is corrected, comorbid disorders must also be addressed. These include ODD (oppositional defiant disorder), anxiety disorder, OCD (obsessive compulsive disorder), and PDD (pervasive developmental disorder). These will be discussed in the next section.

Dosing and side effects

Dosing with the stimulant medication is not clearly formulated. This is more of an art than a science and requires sensitivity to improvements and side effects. Parents (rightfully) are most concerned with side effects. Even though side effects may exist, I like parents to regard AD/HD treatments with medications as a risk free proposition. “You like it, we will go ahead. You don’t like it, we can always decrease the dose or stop the medication.” I promise my patients’ parents that I will not let their children suffer any side effects. This however places a great responsibility upon the parents to watch, observe, and be sensitive to any undesirable changes that only they can detect, such as minor “changes in personality, mild irritability, etc.” Therefore, any changes of the doses of medications should be made over weekends and holidays, so that possible dose related side effects may be readily observed and corrected. About 80-90% of side effects are dos related and resolve as proper adjustments are made.

Dosing with short acting Adderall starts low and is gradually increased, as directed by the physician, until the best effect is obtained. Certain increases may be made on a weekly basis. And if side effects are observed, the dose should be decreased to the previous one that did not cause the side effects. This approach may minimize the side effects.

Some side effects of the stimulant medication include, most commonly, a decrease in appetite. An allergic reaction (rash), which is an indication to stop the medication and never use it again, is rare. Side effects that are dose related (too much medicine) include increased irritability, tiredness, and “zoning out” (being too focused on one thing). These respond to lowering of the dose. In about 2% of children, nervous tics may develop, eye twitches, facial grimacing, neck movement, or frequent throat clearing. This may require stopping the treatment or decreasing the dose. Other unusual side effects may include abdominal pain, headaches, sleeping difficulties (if dosing late in the afternoon), and increased heart rate. No fatality was directly related to stimulant medications if dosed appropriately.