ADHD medicine types: stimulants, non-stimulants and how they differ

ADHD is linked to differences in brain networks that rely on dopamine and noradrenaline. Medicines in this area increase the availability or effect of these chemicals in regions involved in attention and impulse control. Stimulants act quickly, within an hour, and wear off over hours depending on whether they are immediate or modified release. Some non-stimulants take weeks to reach full effect but act smoothly across the day.

NICE guidance (NG87) describes choices according to age and presentation. In adults, a stimulant such as lisdexamfetamine or methylphenidate is generally the first option, with the alternatives described below. Choice also depends on other conditions, risks and preferences.

• Reduced appetite and weight loss, particularly with stimulants.

• Difficulty sleeping, especially with later doses.

• Headache, stomach ache, dry mouth.

• Raised heart rate and blood pressure.

• Irritability, anxiety or emotional flatness in some people.

• Drowsiness and low blood pressure with guanfacine; nausea with atomoxetine.

People with certain heart conditions, uncontrolled high blood pressure, a history of psychosis, severe anxiety, tics, seizures or substance misuse need careful assessment. Alcohol and drug use affect risk and effectiveness. Medicines should be stored safely, because stimulants have potential for misuse and diversion. The MHRA publishes safety updates, and side effects can be reported through the Yellow Card scheme.

The process is often trial and adjustment. A specialist starts at a low dose, increases gradually and reviews benefit and side effects. If one medicine does not help or is not tolerated, an alternative may work better. Many people use medicine on selected days or hours, depending on need and tolerability, with agreement from their prescriber.

Psychoeducation, cognitive behavioural therapy adapted for ADHD, coaching, practical organisation strategies and adjustments at work or study complement medicines. Treating sleep, anxiety and depression also improves function.

It is reasonable to ask why a particular medicine is being suggested for you, how long you should try it before judging it, which side effects are most likely and how they can be managed. Ask what happens if you are pregnant or planning pregnancy, what to do about caffeine and alcohol and how often you will be reviewed. Ask also about practical points, such as how many days of supply you can receive at once and what to do if a prescription is lost. Written information and a named contact make early weeks easier.