Although the use of illegal drugs in general has decreased among young people, cannabis is still the ‘most widely used illicit substance among young people, and prevalence rates in the UK are among the highest in Europe.[1]’ However the term ‘illegal’ may not apply to marijuana for much longer. Many countries around the world have begun to legalise the drug. Some purely for medical reasons whereas others have gone as far as legalising it for recreational use. While it is still illegal in the UK, some police forces have decided to take a more relaxed attitude when finding people with it in their possession. What does this actually mean, and what are the implications for our kids?

What is marijuana?

On the streets it goes by names such as Bud, Hash, Ganja, Grass, Mary Jane, Reefer, and Skunk. Marijuana comes from the dried leaves and flowers of the Cannabis sativa or Cannabis indica plants. The active ingredient responsible for its psychotropic, or mind-altering, effects is THC, the content of which has significantly increased in recent years: from around 3.74 percent in the early 1990s to nearly 10 percent in 2013.

How is marijuana used?

It can be smoked, mixed with tobacco and put in joints, bongs or pipes. It can be cooked in food, normally called hash brownies, but also in cakes or biscuits. Furthermore you can find it brewed and drunk in a tea like mixture. A new way adolescents are abusing marijuana is through a process called “dabbing”, whereby they smoke or vape the resins of the plant. ‘The extract is typically made by pouring a solvent over marijuana plants to extract the THC, then letting the solvent evaporate.[2]

Since the resins are unregulated and, therefore, untested, ‘medical experts have begun to raise alarms, saying the substance is too new to be fully understood and could pose unknown health risks.[3]

If you haven’t heard of dabbing before, listen out for other words your children might be using for it, such as ‘shatter, butter, and honey[4]’. It is definitely something for parents to be concerned about, as it seems to be a much more extreme way of consuming marijuana than any that has gone before. Teenagers are reporting that they often pass out after inhaling the resins and can feel its numbing effect in their system for hours. Some even report it as hallucinatory. The negative consequences of dabbing can be pretty terrifying too. Emily Feinstein, the director of health law and policy for the National Center on Addiction and Substance Abuse, when speaking to the New York Times said, “there is some evidence to suggest that the outcomes, like the effects, may be supercharged… Side effects can include: a rapid heartbeat, blackouts, psychosis, paranoia and hallucinations that cause people to end up in psychiatric facilities.[5]

Marijuana and the brains of our children

Obviously there is a certain amount of controversy surrounding the new laws and leniency towards marijuana and its use today. One of the concerns is that legalising the drug will encourage young children to use it more as it will be more readily accessible. This is a concern because there is still evidence to show that the developing brain of a teenager is particularly vulnerable to potentially long lasting alterations and damage from the drug. According to Susan Weiss, PhD, director of the division of extramural research at the National Institute on Drug Abuse (NIDA), “there’s a growing literature, and it’s all pointing in the same direction: Starting young and using frequently may disrupt brain development.[6]

Although marijuana has shown some promise in research around it treating pain, seizure conditions, muscle spasms and sickness from chemotherapy, it is thought that these conditions have been made better through cannabidiol, which is the part of the plant that doesn’t produce mind altering effects. The reason most of our young people use marijuana recreationally is for the mind altering effects which comes from the THC. ‘And evidence is mounting, says Weiss, that THC is not risk-free.[7]

Much research has been done showing that marijuana use can affect functions such as attention, memory, learning and decision-making. Researchers at the University of Montreal monitored and tested 3,800 adolescents over four years, starting from around the age of 13, showing that those using marijuana regularly demonstrated ‘lagged (neurotoxic) effects on inhibitory control and working memory and concurrent effects on delayed memory recall and perceptual reasoning (with some evidence of developmental sensitivity)[8].’

However, the jury is still out as to whether the blame for these issues experienced by adolescents is purely down to marijuana use. There has been evidence that suggests that other factors such as ‘peer influence, emotional distress or a tendency toward problem behaviour could predispose people to drug use as well as poor life outcomes.[9]’ However, one longitudinal study from New Zealand showed some concrete and troubling findings regarding marijuana use in adolescence and a drop in IQ. Following 1000 New Zealanders born in 1792 until the age of 38. ‘Cannabis use was ascertained in interviews at ages 18, 21, 26, 32, and 38 y. Neuropsychological testing was conducted at age 13 y, before initiation of cannabis use, and again at age 38 y, after a pattern of persistent cannabis use had developed.[10]’ The evidence they found by assessing this cohort demonstrated that long-term, heavy cannabis use causes neuropsychological impairment that remained even if a participant had had an extended period of abstinence from the drug.

The fact is, whatever the results of studies done regarding marijuana use among our children. We do know that at least until our early or mid-20’s, our brains are still under construction. During this period of neurodevelopment it is possible that the brain is ‘uniquely susceptible to lasting damage from marijuana use.[11]’ Without knowing for sure if changes in the brain that have been demonstrated to occur after marijuana use are permanent or not, and without any concrete, undeniable evidence that there is a safe level of marijuana use, why would we want our kids to risk it?


[1] Melrose, M et al. ‘The impact of heavy cannabis use on young people’s lives’

[2] Maslin Nir, S., The New York Times. (2016). Chasing Bigger High, Marijuana Users Turn to Dabbing’. accessed 2/9/2019

[3] ibid.

[4] ibid.

[5] Maslin Nir, S., The New York Times. (2016). Chasing Bigger High, Marijuana Users Turn to Dabbing’. accessed 2/9/2019

[6] Weir, K. Marijuana and the developing brain. American Psychological Association. November 2015, Vol 46, No. 10. Print version: page 48

[7] ibid.

[8] Jean-François G. Morin, Mohammad H. Afzali, Josiane Bourque, Sherry H. Stewart, Jean R. Séguin, Maeve O’Leary-Barrett, and Patricia J. Conrod. A Population-Based Analysis of the Relationship Between Substance Use and Adolescent Cognitive Development. American Journal of Psychiatry 2019 176:2, 98-106

[9] Weir, K. Marijuana and the developing brain. American Psychological Association. November 2015, Vol 46, No. 10. Print version: page 48

[10] Madeline H. Meier, Avshalom Caspi, Antony Ambler, HonaLee Harrington, Renate Houts, Richard S. E. Keefe, Kay McDonald, Aimee Ward, Richie Poulton, and Terrie E. Moffitt. Persistent cannabis users show neuropsychological decline from childhood to midlife. PNAS October 2, 2012 109 (40) E2657-E2664; https://doi.org/10.1073/pnas.1206820109

[11] Weir, K. Marijuana and the developing brain. American Psychological Association. November 2015, Vol 46, No. 10. Print version: page 48