It’s a question often asked by worried parents who have been fed a pack of lies about the effects of medication for ADHD, a physical, neurochemical brain disorder.

There is a great deal of misunderstanding on this subject, exacerbated and sometimes caused entirely by incompetent journalism.

The murder trial of a 19-year-old cannabis addict who stabbed his grandmother to death in Britain two years ago began today (April 20, 2022), according to a report published by the British Daily Mail.

The 69-year-old woman, a restaurant owner, was stabbed at least 17 times by her grandson, who at the time was age 17. He had been diagnosed in 2018 with ADHD. He was also apparently being treated for anxiety, but was abusing cannabis as well.

Following the murder, the teen dialed police, and turned himself in.

“In the months leading up to the killing he had become a habitual cannabis user, regularly smoking a couple of joints every day,” according to the Daily Mail, quoting court papers. “His behavior started to deteriorate and he began to skip college and often failed to turn up for work at the family restaurant.” The teenager also started selling his clothing to get the money to be able to buy cannabis.

His father believed the ADHD medicine he had been prescribed — Elvanse (known in the United States as Vyvanse (generic: Lisdexamfetamine) — was largely to blame for his son’s problems and would flush the drugs down the toilet before the teen moved to his grandmother’s house in Brighton, where he continued his cannabis abuse.

(Ed. Note: Elvanse is a long-acting, once daily medication for the control of the symptoms of ADHD. Elvanse is the first of a new class of dopamine modulators approved in Europe that uses pro-drug technology to release the active drug in the body. It is available in the USA and Canada under the trade name Vyvanse® for the treatment of ADHD in children, adolescents and adults, and is currently the most prescribed branded ADHD medicine in the USA. Elvanse has been prescribed to treat more than 4 million patients in the USA, Brazil and Canada.)

The teen had also been prescribed Xanax (alprazolam), which the Daily Mail erroneously categorized as an anti-depressant. Xanax does not treat depression. It is an anxiolytic, meaning it is prescribed to address symptoms of anxiety, including panic attacks and post-traumatic stress disorder (PTSD).

The teen’s grandmother had written to his psychologist to let her know he was continually smoking weed. She said he was “suffering paranoia” and was mostly uncooperative.

A friend likewise told police the teen had become “negative and despondent,” as well as “quite paranoid.”

The teen admitted to the killing, but is denying the murder charge.

So, now let’s unpack the above tragic tale to take a look at some relevant factors.


To begin with, the teen was diagnosed in 2018, at the age of 15 or 16. It is possible that by this time he had already had become addicted to cannabis. But even if he had not, his father’s deliberate sabotage of the prescribed treatment may have increased the risk.

ADHD children and teens who receive appropriate medication for the condition are les likely to abuse or become addicted to drugs and/or alcohol.

Leading ADHD researcher Dr. Russell Barkley writes in his article, “Does the treatment of attention-deficit/hyperactivity disorder with stimulants contribute to drug use/abuse? A 13-year prospective study” that “Stimulant treatment in either childhood or high school was not associated with any greater risk for any formal Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised drug dependence or abuse disorders by adulthood. Treatment with stimulants did not increase the risk of ever having tried most illegal substances by adulthood except for cocaine.”

Barkley notes that the findings of his study concur with 11 previous studies in finding “no compelling evidence that stimulant treatment of children with attention-deficit/hyperactivity disorder leads to an increased risk for substance experimentation, use, dependence, or abuse by adulthood.”

Equally prominent ADHD researchers Tim Wilens, Joseph Biederman and several others go further, pointing out in their article, “Does stimulant therapy of attention-deficit/hyperactivity disorder beget later substance abuse? A meta-analytic review of the literature“, that their results “suggest that stimulant therapy in childhood is associated with a reduction in the risk for subsequent drug and alcohol use disorders.”

Brain chemistry has a lot to do with this.

ADHD brains have low levels of a neurotransmitter called norepinephrine. Norepinephrine is linked arm-in-arm with dopamine.

The cannabis receptors are densely populated in prefrontal and limbic areas in the brain, which are involved in reward and motivation. They regulate signaling of the brain chemicals dopamine, gamma-aminobutyric acid (GABA) and glutamate.

Dopamine is involved in motivation, reward and learning. GABA and glutamate play a part in cognitive processes, including learning and memory.

Cognitive impairments have been noted in mild cannabis users as well as those addicted to it, and those who abuse this substance have been shown to have a tendency to make riskier decisions than others and have more problems with planning.

ADHD occurs primarily in the pre-frontal and frontal lobe of the brain, areas that help people to organize, plan, pay attention, and make decisions. These areas of the brain may mature a few years later in people with ADHD.

The frontal lobe is the area of the brain responsible for: problem solving, memory, language, motivation, judgment, impulse control, social behavior, planning, decision-making, attention, ability to delay gratification and time perception.

In addition, cannabis abuse / addiction has been known to trigger latent schizophrenia.

Cannabis use during adolescence has also been reported as a risk factor for developing psychotic experiences as well as schizophrenia“, according to the article, “How Cannabis Affects Our Cognition and Psychology,” published in Neuroscience News, and sourced from The Conversation.

“One study showed that cannabis use moderately increases the risk of psychotic symptoms in young people, but that it has a much stronger effect in those with a predisposition for psychosis (scoring highly on a symptom checklist of paranoid ideas and psychoticism,” according to the article, published April 13, 2022.

As noted above, untreated ADHD can raise the risk of substance and alcohol abuse.

The young man now standing trial for the murder of his grandmother had a history of mood disorder — which can create a predisposition for psychosis — as well as having untreated, or inadequately treated ADHD due to his father’s destruction of prescribed medication.

The issue of personal responsibility for one’s actions cannot, however, take a back seat in this case. There are millions of children, teens and adults around the world who have ADHD and mood disorders, and very few of them stab their grandmothers.

The trial is continuing, and with it the likely prospect of testimony by clinical professionals along the way.

Can ADHD medication account for, or cause, such behavior? The answer is a categorical “NO.” But what about cannabis?

The jury’s still out on that one.

Image courtesy, Ronny Overhate at Pixabay.