Some of my work in the community involves spending time with young people who live in care.

Last week I was in a young offenders' institution. This is a prison for people between the ages of 16 and 21. Midweek I ran classes at a residential school for children who have been excluded from every other form of education, usually due to their "challenging" behaviour. On Friday, I visited a young man currently being detained in a secure unit or a "secure".

This is essentially where teenagers go when they are too young to be sent to jail.

People are sent to these places for different reasons but there are common themes that emerge from almost everyone's story. The first being poverty. The second, some form of abuse or neglect which usually occurs in the context of substance misuse or full-blown addiction.

The addictions often begin as coping strategies but over time they become the main problem. And in many cases the addictive behaviours are passed down through generations.

I have seen first-hand how they can tear families and communities apart.

And yet there are still people out there who genuinely believe addiction is a myth.

There are hundreds of thousands, if not millions, who wholeheartedly believe that the parents of these young people consciously choose to continue using alcohol and drugs because they enjoy it and not because they are struggling with psychological and physical dependencies.

Some have gone further, like the formidable right wing polemicist Peter Hitchens, and called for even harsher prison sentences for addicts who commit drug-related offences.

I'm not part of the no-platform brigade, so regardless of how deeply this issue has personally affected me, I do not believe in condemning or socially exiling people based on their opinions, bonkers as they are.

However, my own experiences as a recovering addict, the child of a dead alcoholic and as a someone operating in communities where substance misuse is alarmingly prevalent, tell me that addiction deniers are away with the bloody fairies.

I can still recall swearing off the drink one morning but somehow being drunk by midday, taking an overdose of pills in front of my partner and being rushed to hospital, put on a drip, and discharged two days later - only to find myself staring at the bottom of another bottle within an hour.

I recall watching my friends, both heavy drinkers, lowering our fallen comrade, a chronic alcoholic, into his early grave as I sipped whisky from a hip-flask, thinking one of us wasn't far behind him.

There's nothing quite as scary as reaching for a box of codeine-laced painkillers for a night cap, only to realise you have finished the whole box within 24 hours and that there's a big chance your liver will fail if you don't go immediately to casualty.

Then my mind turns to people who have mutilated their own bodies, to free themselves of restraints, so they could escape rehab facilities to use drugs. I think of prisoners who have resorted to licking up someone else's vomit in the hope of imbibing the faintest trace of alcohol into their systems or the vulnerable women risking their lives every night as sex workers just to feed their unforgiving habits.

And I think of the millions of people who have plunged filthy needles deep into their own veins, often in front of their own children, hoping desperately to experience a short reprieve from their horrific reality, only to convulse and die after misjudging the dose.

It's hard to fathom how anyone could consciously choose to behave in this manner because they enjoyed it. Yes, they may enjoy the temporary relief when they get their fix, but every other second of their life is a nightmare - believe me.

Surely, it's beyond doubt that addiction is a mental state, triggered by a chemical reaction in the brain that subverts or severely impairs a person's decision-making faculties? A phenomenon that centres in the mind of the sufferer, manifesting as a mental compulsion, often coupled with a physical craving, which infects a human being's basic integrity.

It's primary symptom: a cunning torrent of dishonest thinking that assails a person's better judgement, slowly undermining, deforming and perverting their humanity until recovery - or death.

Ever reach for a packet of biscuits, genuinely intending to have one but end up eating the whole packet? Well substance misuse works in pretty much the same way except the reaction is much more toxic.

People who believe otherwise, who swear dependancy is a myth, are perfectly entitled to their view. But they have either not seen addiction up close or they are, I'm sorry to say, mental.

And yes, it's correct that the threat of prison does deter some people from engaging in criminal activities and that a stint behind bars, whether a few nights in the cells or a few months in prison, can often have the desired corrective effect when it comes to drug-related offending.

However, you need only spend an hour in any of Her Majesty's prisons to see that drugs are just as easy to obtain behind bars as they are anywhere else. Sending an addict to prison to get over their addiction is like sending a type-2 diabetic to Krispy Kreme to regulate their blood sugar.

Our young offenders' institutions are packed to capacity, often with people who've suffered abuse and neglect as children. Local authorities can't always afford to send troubled kids to residential schools because the financial costs are so great, which increase their chances of being excluded from mainstream schools or being brought before children's panels.

And for many of them the last stop before prison will be a secure unit, where beds are dwindling every year as vital services are cut.

A social work and prison system at absolute breaking point, full of troubled young people from dysfunctional and abusive families, should be reason enough to realise the debate about the existence of addiction is over. If you don't believe in addiction then the rest of us must move on without your input.

Because the only thing we should be arguing about now is how to drive this social plague from the lives of our country's most vulnerable children.

Comment by Darren McGarvey. Darren is a writer and broadcaster and, under the name Loki, a rapper and hip hop artist. His music can be found here.