ADHD Medications: How Do They Work and Should I Take Them?

Adult ADHD is a treatable disorder. The best treatment approach is a combination of oral medication and therapy, followed by secondary support such as coaching, psychoeducation, mentoring and peer-support groups. None of these are permanent cures, nor will they solve all the problems that ADHD is associated with. They can help people concentrate better, sometimes reduce anxiety and achieve tasks and goals. Obviously, every medical treatment comes with risks and although research has demonstrated the long term safety of ADHD medicines, they do have a number of side effects to be discussed with your doctor.

There are two types of approved medicines for treating adult ADHD; stimulants and non-stimulants. Stimulants are drugs that normally speed up the body’s systems, but at low doses, they have beneficial effects on the core traits of ADHD. The three stimulant drugs approved in the UK are methylphenidate (e.g. Ritalin, Concerta) and the two classes of amphetamine-based drugs are dexamfetamine (e.g. Adderall, Dexedrine) and lisdexamfetamine (e.g. Elvanse, Vyvanse). Research suggests that the amphetamine-based drugs are more effective than methylphenidate.

All of the stimulant drugs work by increasing the activity of chemicals in the brain such as dopamine and noradrenaline, which do not work as well in people with ADHD. It is not uncommon however for adults with ADHD to be hesitant when offered medicine to treat the disorder.

Just like for the formal diagnosis, the initial prescription for ADHD must be given by a specialist psychiatrist and cannot be given by a GP (at least in the UK). The exact type and amount of medication to be taken can be overseen by the clinical team (e.g. a psychiatric nurse). This process is called titration. Once titration is complete, stable prescriptions can be handled by your GP as part of a ‘shared care agreement’.

The drugs

Methylphenidate (Ritalin) is the most commonly prescribed drug in adult ADHD. Methylphenidate works by blocking the removal of dopamine and noradrenaline, so they hang around in your brain for longer. A meta-analysis [glossary] of 18 clinical trials showed that methylphenidate has a moderate effect on ADHD symptoms at a dose of 57mg/day, with less effective results if given as a slow-release form. Common side effects of methylphenidate include insomnia, decreased appetite, nausea and headache.

The amphetamines (lisdexamfetamine and dexamfetamine, also known as Elvanse and Adderall respectively) work by increasing the release of dopamine, noradrenaline, and serotonin plus also blocking their removal from the brain, thus increasing their levels in the brain. Evidence suggests that amphetamines should be the first choice drug for treating adult ADHD, however, this is not the case. Side effects for amphetamines include increased heart rate and blood pressure, insomnia and loss of appetite.

The non-stimulant based drug that is licensed for adult ADHD is called atomoxetine (also known as Strattera). Atomoxetine works by blocking the removal of noradrenaline, meaning it stays in the brain for longer. Atomoxetine does not have any stimulant effects but still is effective in treating adult ADHD.

The ‘off-license drugs’

There are some other drugs that psychiatrists may be willing to prescribe ‘off license’ (this means they are drugs approved for other uses but they may be beneficial in adult ADHD). These include bupropion (also known as Wellbutrin). Bupropion is an anti-depressant that has emerging evidence of effectiveness in treating adult ADHD, but the evidence is of low quality.  Other ‘off license’ options include modafinil and venflaxine, which have a much weaker evidence base and are therefore not licensed. They may be given to you if other treatments fail or if the side effects are not tolerable.

Whilst these medicines are not a permanent cure for ADHD and should be part of a treatment plan including psychoeducation, psychiatric care and ongoing community support, ADHD medicines are relatively safe, generally tolerable and effective at reducing a number of the symptoms thought to be most problematic for adults with ADHD.

Author: Alex Conner PhD.

Editor: James Brown PhD.