For a long time, Marc Lewis felt a body blow of shame whenever he remembered that night.

"We thought you were dead," accused one of  his mates, leaning over him. Lewis was slumped half-naked in a bathtub. "We were just talking about what to do with the body."

Lewis was at only the beginning of his odyssey into opiates. After this overdose, he dropped out of university and didn't pick up his studies for another nine years. At the next attempt, he was excelling at clinical psychology when he made the front page of the local paper. He'd been busted raiding a pharmacy for goodies, hopefully Demerol or Methedrine. That was careless; he'd been successfully pulling off three or four break-ins a week.

That was 34 years ago. Now 64, Professor Marc Lewis is a developmental neuroscientist, based at the Radboud​ University in Nijmegen​ in the Netherlands. He details his early exploits in 2011's Memoirs of an Addicted Brain, with the sort of thrilling detail that ought to give you some kind of biochemical response. His new book, The Biology of Desire: Why Addiction Is Not a Disease, cements his image as a rock star of neuroscience by loudly challenging the status quo.

The prevalent theory in the United States, and to some degree in Australia, is that addiction is a chronic brain disease – a progressive, incurable condition that can be kept at bay only by fearful abstinence. There are variations of this disease model, one of which became the basis of 12-step recovery and the touchstone of the vast majority of rehab programs.

Lewis argues that addiction – or dependence, as we would call it in Australia – is the result of "deep learning", probably triggered by stress or alienation. It can duly be unlearned by forging stronger synaptic pathways via better habits.

The implication for the $35 billion-dollar treatment industry in the US is that tackling addiction as a medical issue should be only a small element of a more holistic approach. The problem is, there's a lot of vested interest – and financial investment – in perpetuating the disease model.

There's consensus on the science, at least. As Lewis explains to Fairfax Media, repeated alcohol and drug use causes tangible changes in the brain. "We all agree on that," he says. "The changes are in the actual circuitry, within the synapses that connect the striatum to other parts.

"The longer a time that you spend in your addictive state, the more the cues attached to your drug or drink of choice is going to turn on the dopamine system," Lewis says. At the same time as the release of dopamine, nicknamed the feel-good chemical, is being ramped up, there is a decreased activity in areas of the brain responsible for judgment and decision-making.

According to the globally influential, US-based National Institute of Drug Abuse (NIDA), these neurobiological changes are evidence of brain disease. Lewis disagrees. Such changes, he argues, are induced by any goal-orientated activity that becomes all-consuming, such as gambling, sex addiction, internet gaming, learning a new language or instrument, and by powerfully valenced activities such as falling in love or religious conversion. And while the American Medical Association may have classified alcoholism as a disease in 1956 and obesity in 2013, it hasn't gone so far as to similarly smote love or Catholicism.

"It even applies to making money," Lewis says of this deep learning. "There have been studies showing that people making high-powered decisions in business and politics also have very high levels of dopamine metabolism in the striatum, because they're in a constant state of goal pursuit."

The result of constantly stimulating this reward system keeps the user focused only on the moment. "You can't think about tomorrow or next week," says Lewis. "You've lost the idea of yourself being on a line that extends from the past into the future. You're just drawn into this vortex that is the now."

While the disease concept suggests that a person who has become abstinent will be in perilous remission forever, Lewis argues that new habits can overwrite old. "People have to really be ready, because there has to be a powerful surge towards other goals," says Lewis. "Goals about their relationships and feeling whole, connected and under control. The striatum is highly activated and looking for those other goals to connect with.

"There was a study made on addicts of cocaine, alcohol and heroin, and it showed that six months to a year into their abstinence there were regions of the prefrontal cortex that had previously showed a decline in synaptic density from underuse, which had returned to baseline and then gone beyond baseline. That indicates growth of powerful new synaptic networks, and if you're setting up new paths then you're deactivating old paths, because they're being used less."

Lewis certainly isn't the first scientist to believe that "most people who become addicted are experiencing some kind of loneliness, depression or alienation." He cites psychologist Stanton Peele – who has table-thumped the idea since the 1970s that addiction is a learned behaviour influenced by personal suffering – and neuropsychopharmacologist Carl Hart, who wrote a hair-raising memoir of his own and who insists "drugs aren't the problem", rather it's draconian drug laws and marginalisation.

What's undeniable is that the disease concept they reject is deeply embedded into our culture, largely through Alcoholics Anonymous. There can be few American TV serials that haven't depicted a recovering alcoholic leaving their place in the circle of chairs, to attempt to control their own drinking. When the doomed character dramatically relapses in a bar, the message reinforces the "Minnesota Model" of disease, adopted by AA in the 1950s: that alcoholism is an involuntary disability, not the symptom of an underlying problem.

The first of AA's 12 steps states: "We admitted we were powerless over alcohol", and AA literature dictates that the reins be handed over to a higher power, at odds to Lewis' belief that sobriety requires self-empowerment. Even as a member diligently attends meetings in church halls, their disease is, it's said, "doing push-ups in the parking lot". In other words, dare to stop attending meetings and it'll king-hit you.

Lewis doesn't entirely discredit AA – which in Australia has close to 20,000 members – but he does suggest that while 12-step recovery "works for some addicts, it does so by promoting a kind of PTSD".

As for rehab, he concedes that medicine needs to be there as an adjunct for those transitioning through withdrawal and maintenance periods, "but you don't need to go to a rehab centre that costs $50,000 a month because it's got medical care that turns out to be bullshit, diluted by 12-step meetings, group meetings and equine therapy.

"It's really a fraud," he says, "when there are better ways, such as outpatient rehab. With that, you're not being whisked off to some pastoral environment, spending a month getting clean, and then being sent back to the environment where you became addicted, which is a set-up for relapse and further costs."

Professor Steve Allsop, from Curtin University, is concerned that the disease model over-simplifies drug and alcohol problems with one-size-fits-all assessment and treatment. As director of the National Drug Research Institute (NDRI), based in Perth, he's instrumental in the policies of the more multifaceted public health model in Australia. This model advocates harm-reduction, with abstinence at one end of the spectrum.

"That's not the same as anarchy," he laughs, "I'm not suggesting anything goes. But some people find in-patient care critical, or long-term help in a collegiate community such as AA, or are helped by particular pharmacotherapies. No single approach has been demonstrated to be 'the way'."

As the US hasn't had the free or subsidised health system that the United Kingdom and Australia enjoys, a person needs to have a definable illness in order to have treatment covered by health insurance, so to have NIDA classify addiction as a chronic brain disease facilitates that process.

Keith Humphreys, professor of psychiatry at Stanford University, says the US National Institute of Health (of which NIDA is a part) funds 90 per cent of the world's addiction research and that funding is being cut which "is devastating to the field".

Carl Hart has complained that, as one opposed to the disease model, he doesn't receive funding any more. As Lewis says: "You don't bite the hand that feeds you."

Professor Suzanne Fraser is the leader of Australia's NDRI's Social Studies of Addiction Concepts Research Program and one of the authors of the book Habits: Remaking Addiction. She says, "The neuroscientific disease approach is heavily promoted by NIDA under the leadership of its director, Nora Volkow​, who believes that calling addiction a disease will reduce stigma.

"It seems Volkow's approach to addiction is in part informed by her own experiences of family drug consumption – in [The] Huffington Post she's called her grandfather's alcohol problem a 'disease of free will'. Like other researchers her view is shaped by her personal experiences, yet NIDA's research is presented as though it has achieved a bias-free viewpoint, from which it can tell us the truth of drugs and addiction."

Professor Alison Ritter​, director of the Drug Policy Modelling Program at the University of NSW says that when the disease model was first adopted by NIDA it was to both de-stigmatise addiction and, by making it a medical condition, it would be eligible for government funding for treatment and research.

During the 1990s – known as the "decade of the brain" – advancements in neuroscience and brain imaging meant "technology caught up with the terminology," Ritter says. "There seemed to be a shift from the term 'disease' as a rhetorical device to something that Americans believed literally. This simplifies dependence down to brain chemistry. In reality it is a complex cultural, social, psychological and biological phenomenon."

Ritter predicts fatigue with the brain disease model. "It has not produced any new technologies for treatment nor necessarily decreased stigma or improved the lot of people who experience dependence problems," she says. "So in a sense, there is this available space to ask: 'What has it been good for, if anything?'"

For now, Lewis is looking forward to hearing about the "progressive-sounding" system in Australia when he speaks at the Melbourne Writers Festival August 30 and then  September 6 at the Festival of Dangerous Ideas in conversation with Johann Hari, author of Chasing the Scream: The First and Last Days of the War on Drugs.

"I agree with his [Hari's] emphasis on the importance of connection," says Lewis. "He says 'the war on drugs' is exactly the wrong term and I agree with that, too."

Not all of Lewis' meetings are likely to be so harmonious – he's guaranteed to lose friends and alienate people at every conference he attends, though he's particularly holding out for a pas de deux with the NIDA's Nora Volkrow.

"I'm sure there are people out there who think I'm a fraud," Lewis laughs, when asked if some researchers might grumble that he is biased by his own success story of giving up drugs his way. "For this new book there were three customer reviews on Amazon before it had even come out, giving it one star. These people proclaimed that I must be an asshole: 'If Lewis is a scientist then I'm an astrophysicist.' They probably think I'm making excuses for myself. But I think my credentials are pretty good."

Allsop believes  Lewis' mainstream approach is a good tool with which to debate these paradigm clashes. "Those of us in the public health sector need to engage much more effectively in informing the community," he says.

Lewis himself knows that the success of his book is a double-edged sword. "I did this talk show in New York and one of the callers was pleading with me, 'Don't take this away from us. I need this in order to get on with my recovery.' That's pretty heartbreaking for me. I don't want to take away from somebody something that's going to make them feel better. I just think in the big picture the disease model is doing more harm than good."

Professor Marc Lewis appears at Melbourne Writers Festival, Deakin Edge, August 30, and at the Festival of Dangerous Ideas, Sydney Opera House Playhouse, September 6.

Isn't addiction genetic?
High-profile addiction experts such as Dr Drew Pinsky​ promote the message that "if you don't have the gene, you don't get the disease".

Neuroscientist and author Marc Lewis says: "There's no gene for addiction or even a cluster of genes.  Rather, it's a combination of features, each of which has some genetic loading, such as impulsiveness, frustration tolerance and sensitivity to rejection.

"Even a high or low IQ could be a genetic factor because both can make you vulnerable to different kinds of environmental stress."

According to Lewis, the bedfellows of dependence are anxiety, attention deficit hyperactivity disorder (ADHD) and obsessive compulsive disorder (OCD) which tend to be hereditary traits that can be triggered by stress or shame, such as trauma, loss of a relationship or job, and societal disruption or oppression.

Curtin University's Professor Suzanne Fraser says that until about 10 years ago, the scientific focus was on the genetics of addiction, "but since then geneticists have acknowledged that genes are too complex to cause addiction".

Biological causes, she says, are appealing because they don't ask us to question our social arrangements. Genes, neurochemistry, hormones, she says, "all have at times been presented as the basis for complex social problems like addiction".