What are the risks of long term ADHD medication use and do benefits continue?
Attention deficit hyperactivity disorder (ADHD) is a condition that can affect all stages of life. Medication is not the only treatment, but it is often the treatment that can make the most obvious difference to a person who has difficulties focusing attention, sitting still or not acting on impulse.
But what happens once you’ve found the medication that works for you or your child? Do you just keep taking it forever? Here’s what to consider.
What are ADHD medications?
The mainstay of medication for ADHD is stimulants. These include methylphenidate (with brand names Ritalin, Concerta) and dexamfetamine. There is also lisdexamfetamine (branded Vyvanse), a “prodrug” of dexamfetamine (it has a protein molecule attached, which is removed in the body to release dexamfetamine).
There are also non-stimulants, in particular atomoxetine and guanfacine, which are used less often but can also be highly effective. Non-stimulants can be prescribed by GPs but this may not always be covered by the Pharmaceutical Benefits Scheme and could cost more.
How stimulants work
Some stimulants prescribed for ADHD are “short acting”. This means the effect comes on after around 20 minutes and lasts around four hours.
Longer-acting stimulants give a longer-lasting effect, usually by releasing medication more slowly. The choice between the two will be guided by whether the person wants to take medication once a day or prefers to target the medication effect to specific times or tasks.
For the stimulants (with the possible exception of lisdexamfetamine) there is very little carry-over effect to the next day. This means the symptoms of ADHD may be very obvious until the first dose of the morning takes effect.
One of the main aims of treatment is the person with ADHD should live their best life and achieve their goals. In young children it is the parents who have to consider the risks and benefits on behalf of the child. As children mature, their role in decision making increases.
What about side effects?
The most consistent side effects of the stimulants are they suppress appetite, resulting in weight loss. In children this is associated with temporary slowing of the growth rate and perhaps a slight delay in pubertal development. They can also increase the heart rate and may cause a rise in blood pressure. Stimulants often cause insomnia.
These changes are largely reversible on stopping medication. However, there is concern the small rises in blood pressure could accelerate the rate of heart disease, so people who take medication over a number of years might have heart attacks or strokes slightly sooner than would have happened otherwise.
This does not mean older adults should not have their ADHD treated. Rather, they should be aware of the potential risks so they can make an informed decision. They should also make sure high blood pressure and attacks of chest pain are taken seriously.
Stimulants can be associated with stomach ache or headache. These effects may lessen over time or with a reduction in dose. While there have been reports about stimulants being misused by students, research on the risks of long-term prescription stimulant dependence is lacking.
Will medication be needed long term?
Although ADHD can affect a person’s functioning at all stages of their life, most people stop medication within the first two years.
People may stop taking it because they don’t like the way it makes them feel, or don’t like taking medication at all. Their short period on medication may have helped them develop a better understanding of themselves and how best to manage their ADHD.
In teenagers the medication may lose its effectiveness as they outgrow their dose and so they stop taking it. But this should be differentiated from tolerance, when the dose becomes less effective and there are only temporary improvements with dose increases.
Tolerance may be managed by taking short breaks from medication, switching from one stimulant to another or using a non-stimulant.
Too many prescriptions?
ADHD is becoming increasingly recognised, with more people – 2–5% of adults and 5–10% of children – being diagnosed. In Australia stimulants are highly regulated and mainly prescribed by specialists (paediatricians or psychiatrists), though this differs from state to state. As case loads grow for this lifelong diagnosis, there just aren’t enough specialists to fit everyone in.
In November, a Senate inquiry report into ADHD assessment and support services highlighted the desperation experienced by people seeking treatment.
There have already been changes to the legislation in New South Wales that may lead to more GPs being able to treat ADHD. Further training could help GPs feel more confident to manage ADHD. This could be in a shared-care arrangement or independent management of ADHD by GPs like a model being piloted at Nepean Blue Mountains Local Health District, with GPs training within an ADHD clinic (where I am a specialist clinician).
Not every person with ADHD will need or want to take medication. However, it should be more easily available for those who could find it helpful.
Alison Poulton, senior lecturer, Brain Mind Centre Nepean, University of Sydney.