PRETORIA - A mental health crisis is looming among young South Africans amid alarming increases in both vaping and cannabis use. Known as co-use, the trend is being fuelled by poor regulation, loopholes in the law and insufficient attention to youth mental health and well-being, according to University of Pretoria (UP) public health expert Professor Olalekan Ayo-Yusuf.

“Co-use of cannabis and e-cigarettes, also known as vapes, is a symptom of youth disconnection and distress. You cannot blame the youth for this crisis in the making,” said Prof Ayo-Yusuf, Head of UP’s School of Health Systems and Public Health while delivering the 36th UP Expert Lecture in early October. The lecture was titled ‘Youth vaping and cannabis co-use: Policy failure or mental health crisis?’.

Setting the context, Prof Ayo-Yusuf said one in 10 adolescents in South Africa has a mental health disorder and may be suicidal, although there is a tendency towards underdiagnosis and undertreatment of mental health disorders. “Mental distress is high among out-of-school or unemployed youth,” he emphasised.

Describing the connections between cannabis and vaping co-use and mental health disorders, Prof Ayo-Yusuf noted a confluence of possible contributing factors since 2017, when the Western Cape Division of the High Court of South Africa first decriminalised private cannabis use in South Africa, and again from 2020, when the COVID-19 pandemic began, worsening poverty and unemployment in the country.

Cannabis-related psychiatric admissions rise sharply

Prof Ayo-Yusuf said there has been a sharp increase in cannabis-related psychiatric hospital admissions among adolescents since 2017. At one Cape Town hospital, these admissions have risen from 35% of adolescent patients pre-2017 to 65%, with similar trends found at other hospitals.

While increased cannabis-related psychiatric admissions could be associated with greater access to cannabis since decriminalisation, they could also be linked to the increasing potency of THC (the psychoactive compound in cannabis).

A marked increase in THC potency has been observed in the United States and elsewhere, Prof Ayo-Yusuf said, adding that in South Africa, cannabis plant material has high amounts of THC, making it particularly potent.

He said research on the effect of cannabis use on adolescent brain development has shown that adolescence is a vulnerable period for the development of the prefrontal cortex – the part of the brain associated with problem-solving, flexibility, adaptation, judgment and frustration tolerance.

The use of cannabis at this vulnerable stage could lead to learning and memory problems, substance dependence and abuse, and depression and psychosis – even more so when paired with nicotine use.

“The adolescent brain is still developing up to the age of 21. Introducing both nicotine and THC before the age of 21 can disrupt brain circuits related to motivation, learning and emotional regulation,” Prof Ayo-Yusuf said.

Why vaping and cannabis co-use is so worrying

Nicotine use has been growing in South Africa since around 2010, but a significant increase occurred after 2020 – coinciding with the COVID-19 outbreak and the rising popularity of products such as waterpipes (hubbly-bubblies) and newer e-cigarettes.

Overall, smoking in South Africa has increased by 50% since 2018, rising to about 14,9 million smokers currently. The increases have been highest among users of e-cigarettes and waterpipes, both of which have seen usage grow by 200% between 2018 and 2024, Prof Ayo-Yusuf said.

Currently, an estimated 3.3 million South Africans use e-cigarettes daily or non-daily.

The growth in nicotine use – from both vaping and tobacco – has gone hand in hand with the co-use of cannabis, especially among young people.

He pointed to UP research among 2 427 students aged 18 to 25 across 15 South African universities. According to the findings, 33% of the students surveyed used waterpipes, almost 28% were e-cigarette/vape users, just over 25% smoked cigarettes, and 21.5% used cannabis, popularly known as dagga.

What was striking, Prof Ayo-Yusuf said, was the extent of substance co-usage among students surveyed: 11% said they used waterpipes only, while 10.9% said they co-used cigarettes, waterpipes and cannabis. This ranked second only to the use of waterpipes, which he said were “scarily popular” among the youth.

Shared vulnerability explains concerns

Explaining why health researchers are so concerned about vaping nicotine in conjunction with cannabis use, Prof Ayo-Yusuf referred to what he called “shared vulnerability factors”. This refers to people who are at risk for substance use and also for mental health disorders.

“This shared vulnerability between cannabis use and poor mental health has been more strongly associated with vaping nicotine than smoking nicotine, hence our interest in the co-use of vapes and cannabis on mental health,” he said. “This is a lesser-known effect of vaping, as the tobacco industry has aggressively marketed vapes to young people as a relatively safe product to aid in quitting cigarette smoking.”

Prof Ayo-Yusuf turned to the measures he believes should be taken to protect young people’s mental health and well-being in relation to vaping and cannabis.

Strengthen child protection and close policy gaps

One of the crucial steps would be to strengthen child protection clauses in the Cannabis for Private Purposes Act of 2024 and swiftly pass the Tobacco Products and Electronic Delivery Systems Control (TPEDS) Bill, which would regulate vapes, including how they are marketed to young people.

In terms of child protection, Prof Ayo-Yusuf said people under 21 should be restricted from accessing cannabis – especially as most co-using students in the universities’ survey said they had used cannabis before vaping. The current age limit for cannabis use in South Africa is 18.

He also pointed out that the recreational cultivation of cannabis is unregulated, unlike cultivation for hemp and medical use. This has created a policy vacuum. He recommended that cannabis use through smoking or vaping be prohibited indoors where children are present (as is the case with tobacco legislation). Child-proof cultivation and storage measures should be made mandatory in homes, and it should be made clear to adults that any cannabis use in the presence of children is an offence or seen as child endangerment.

Steps also need to be taken to strengthen enforcement capacity, which is weak, and expand youth mental health services. “Coordinated responses are needed across the health, education and law enforcement sectors to prevent long-term harm to youth mental health and wellbeing,” he said. “South Africa needs a multisectoral response that addresses both the supply and demand sides of the issue.”

Finally, he said, the vaping and cannabis industries must be held accountable for aggressive marketing and misinformation.

He pointed to the launch of new vaping products such as cannabidiol (CBD) vapes by big tobacco companies such as British American Tobacco. “When companies like BAT start marketing CBD vapes as a ‘new sensory experience’ or to cater for a ‘variety of moods’, then it should worry the regulators in South Africa, given the policy vacuum.”