The issue has been brought back into focus after new figures revealed there has been a rise in cannabis possession offences at schools, colleges and universities in the West Midlands over the last five years.
It suggests schools and colleges are facing an increasingly difficult battle to keep the drug outside their gates.
Drug experts UKAT say this shows parents should be concerned drugs are making their way into schools more than ever before.
The stats don't show a surge - there was a rise from 50 offences to 64 across the whole West Midlands police force area between 2015 and 2019 - but do point to an upward trend.
Alan Jarvis heads the Base 25 youth service in Wolverhampton, was previously drug action co-ordinator in Walsall and has done work with the Home Office.
He believes it is impossible to keep cannabis out of schools and has a lot of sympathy for headteachers doing their best to keep children safe.
Mr Jarvis said: "Unfortunately, cannabis has become the norm. We have young people being introduced to cannabis by their parents who have weighed up the risk of a young person drinking alcohol and a young person smoking cannabis and consider the risks of cannabis to be less than alcohol.
"Within the Black Country are we live, there are a couple of things to contend with. Cannabis is so easy to grow in your own home. And we are down the road from Junction 10 of the M6, one of the busiest motorway networks in Europe.
"It will never dry up because logistically we are smack in the middle of the country so we have always got stuff coming in. It's a free-flowing system.
"The police are meant to stop this stuff coming in but they are so under-resourced."
He added: "People go on about what schools can do. Schools do as much as they can.
"Prisons have sniffer dogs, guards, cameras and everything else but drugs are more rife in prisons than they are in schools. Realistically what do you expect them (schools) do to if you can't stop it in a closed environment like prisons?"
'Support services needed'
West Midlands Police and Crime Commissioner David Jamieson has taken radical steps to try and tackle drug use, arguing for the introduction of controversial 'drug consumption rooms' for heroin addicts, effectively providing them with an area to shoot up.
The suggestions has raised eyebrows but the hope is the rooms would reduce "needle litter" on the streets, deaths from overdoses and put addicts on a path towards treatment.
He said of the latest figures: "It is a concern that if young people are using the drug more openly near schools, colleges and universities that we need to be doing more to educate on the dangers of illegal substances. The Government should be properly investing in initiatives which reduce crime such as youth and drug support services.
“Our Cannabis Disposal Team work around the clock dismantling cannabis factories across the West Midlands and helping us seize assets from the criminals who are operating them.
“I’m investing in warning people of the dangers of taking cannabis. Some young people are under the misapprehension that there aren’t big risks to smoking cannabis.”
There is also the long-standing argument about whether cannabis should be legalised, allowing police to focus resources on more harmful drugs and cutting off the revenue stream to the dealers.
But Mr Jarvis believes legalising cannabis in the UK in a non-starter and actually presents other dangers.
He said: "Certain people in this country and across the world make a huge amount of money from drugs. If you legalise drugs these people will look for alternative methods of making money which aren't legal. Human trafficking and sex slavery are far worse than drug misuse."
Mr Jarvis says, however, the big problem is that many people buying cannabis on the streets do not know what they are actually smoking.
"The problem we face is with people growing it in their own homes, the THC level can go through the roof. One strong argument for regulation is people can choose what strength they get. It's like going into a pub, ordering a pint of lager and getting a double vodka."
And he warned: "If cannabis gets removed completely they are going to find something else."
A 25-year-old cannabis user from Stafford admits he is "pretty dependent" on the drug.
He said he had smoked cannabis "on and off" for around three years but had smoked daily since the start of the year following a difficult break-up.
He said: "If I go a day without it as soon as I go to bed I can't sleep. It does worry me. If I smoke it when I get back from work it writes the rest of the time off, I can't do anything. I do need to slow down."
He added: "It's so easy to get. It's everywhere. There are so many people doing it."
Smoking is not risk free
It is the social drug of choice for many, smoked openly on the streets and, for many teenagers, all part of being sociable with friends.
But risk-free it is not. Cannabis has proven links with mental illness and in many cases it has ruined lives and led to suicide.
Scientists believe they have identified about 60,000 cases of depression in adults under 35 in the UK, and more than 400,000 in the US, that could be avoided if adolescents did not smoke cannabis.
An international team of scientists looked at 11 studies published from the mid-1990s onwards, involving a total of more than 23,000 people. After taking into account factors including age, mental health issues at the outset and socioeconomic status, the results linked cannabis use to a greater likelihood of later developing clinical depression, having suicidal thoughts or attempting suicide.
The odds of attempting suicide were almost 3.5 times worse among those who used cannabis before the age of 18 than those who did not.
Dr Andrea Cipriani, co-author of the research from the University of Oxford, said: “The number of people who are exposed to cannabis, especially in this vulnerable age, is very high and I think this should be a priority for public health and the medical sector as well.”
The key psychoactive ingredient of cannabis is THC, or delta-9 tetrahydrocannabinol, which binds to receptors in the brain that are particularly common in regions important for emotion and learning as well as rational thinking.
Density of such receptors in these regions peaks during adolescence. That, together with the fact that young people’s brains are still developing, has led to increasing concern about the impact of cannabis on young users.
In some cases continued use of cannabis can cause very serious mental health issues. Recent research suggests that smoking high-potency marijuana every day could increase the chances of developing psychosis by nearly five times.
Another common trait is an inability to be active. Cannabis is associated with an ‘amotivational syndrome’, defined as a diminished or absent drive to engage in typically rewarding activities, like work or physical exercise.