Home » The Real Deal on Drugs » Can ADHD medications cause a positive roadside drug test?

Can ADHD medications cause a positive roadside drug test?

“I know someone who got a positive drug test for methamphetamine when he was driving and he’s never taken that drug. He is on ADHD medication though. In one of your posts you said that this shouldn’t happen, why would it and what should he have done?”

Roadside (or mobile) drug testing (RDT or MDT) involves two tests and you don’t say in your question whether your friend failed both of these tests or not. I’m guessing they most likely only failed the first and when they took the second, more accurate test, they passed. Even so, if they had never used methamphetamine (i.e., speed or ice) and were told by a police officer that they’d just failed a drug test that would be terrifying – so why would this happen?

Firstly, why could ADHD medications possibly cause a problem?

Attention deficit hyperactivity disorder (ADHD) can cause those with the condition to have difficulty focusing and affect learning. Those diagnosed with ADHD are often prescribed stimulant medications to help them concentrate and reduce hyperactive behaviour. There are non-stimulant medications available but these are not used as often.

In Australia, the medications mainly used to treat ADHD are dexamphetamine, methylphenidate and lisdexamphetamine and these can be either short-acting (releasing immediately with the effect lasting about 3-4 hours) or long-acting (lasting much longer, between 6-12 hours). Most young people know these medications by their brand names. Methylphenidate is best known as Ritalin or Concerta and Vyvanse is the brand name for lisdexamphetamine. Dexamphetamine is usually prescribed as ‘dexamphetamine’ or Aspen.

As I wrote in a previous post, the first test used in Australian roadside drug testing is a simple saliva test. This identifies three illicit drugs – cannabis, or more specifically THC, ecstasy (MDMA) and methamphetamine. NSW and Queensland now also test for a fourth drug – cocaine. Of those four drugs it is the testing for methamphetamine that could be potentially problematic for young drivers with ADHD.

Methamphetamine and other forms of amphetamine, including dexamphetamine, are not all the same. As a result, police say that the initial RDT saliva test will not detect different ADHD medications, i.e., their devices only test for methamphetamine. That said, I’ve met a number of young people who’ve told me that they failed the first test for methamphetamine and, like your friend, swear that they’d never used that drug. They all passed the second test – that is a far more accurate laboratory test that will certainly be able to distinguish between different forms of amphetamine – but that’s little comfort for those people who fail that first one through no fault of their own.

Police say that this shouldn’t happen but, to be on the safe side, if you’re prescribed ADHD medication and you’re selected for an RDT, let the officer know what medication you are currently using. Keep an empty packet of it in your glove compartment, where your name can be clearly seen, just in case. I can almost guarantee that the officer conducting the test will tell you that the device will not pick-up that medication and won’t want to see the packet but nevertheless, saying something to them as politely and respectfully as you can let’s them know that you’re a little more aware of the process.

If you are unlucky and do return a positive test result, at least the officer may now have some understanding of why that could possibly have occurred. You’ll still have to do the second test but, don’t panic, if it is an ADHD medication that caused the problem, the more accurate test will make that clear.

Published: August 2023

Recent Posts

Looking for information or support services on alcohol or drugs?

If you or a friend or family member needs assistance in this area, Alcohol and Drug Information Services (ADIS) are available in every state and territory. Each of these are each staffed by trained professionals who can help with your query and provide confidential advice or refer you to an appropriate service in your area.

Scroll to Top