Your brain hijacked -- possessed by a chronic, relapsing brain disease. Scientists now view addiction as a disease, not a behavioural problem.

Brain circuits involved in reward and pleasure, planning and control are dramatically changed. The priority is medical treatment, not shame and blame.

But others challenge what they dub the 'disease rhetoric', arguing it's fatalistic and reductionist.

Do we treat the brain, or the person? And, should we surrender control to the addicted brain?

[Excerpt from transcript:]

Natasha Mitchell: Hello, Natasha Mitchell, great to have your company on ABC Radio National. Today on All in the Mind, drug addiction, and dis-ease over calling it a brain disease.

William Moyers: I have an illness with origins in the brain, a genetic predisposition that's set me up to process alcohol and other drugs differently than 90% of the rest of the population. An allergy of the body, an obsession of the mind, a volatile cocktail that set me up to take me down. Down into the depths of the disease that didn't let go until it all but killed me.

Sally Satel: It's the brain disease rhetoric that I find troubling because it's using the language that we would normally use to describe brain tumours, multiple sclerosis, Alzheimer's -- afflictions that are not initiated by the patient and can't be overcome by the patient's desire to be well. It's very pessimistic and it paints the addict as in a passive position.

Wayne Hall: The advocates of the chronic relapsing brain disease model are very much in favour of increasing access to effective forms of treatment and more humane treatment of people who are addicted. And that's certainly a very commonly expressed hope.

The fear is, and I think it is a realistic one, it's no accident that we've had two inquiries in NSW and Victoria within the last four or five years that I'm aware of -- parliamentary inquiries considering a reintroduction of compulsory treatment for addiction under provisions very similar for those that are used to compulsorily treat people for mental illness. And the rationale and justification for that has increasingly appealed to neuroscience research on addiction.

Natasha Mitchell: Professor Wayne Hall, and before him Dr Sally Satel, staff psychiatrist at the Oasis Drug Treatment Clinic in Washington, DC and a resident scholar at the American Enterprise Institute where you'll also find key players like Paul Wolfowitz, Newt Gingrich, Ayaan Hirsi Ali amongst others. Dr Satel has just penned two provocative pieces confronting what she calls the 'brain disease rhetoric of addiction'. More in a moment.

Former journalist William Moyers, son of the acclaimed journo Bill Moyers, knows what it's like to be diagnosed with a brain disease, a story he tells in his memoir Broken. He's vice-president now of external affairs at the famous drug treatment centre called Hazelden, and I caught him at a conference on addiction at Massachusetts Institute of Technology.

William Moyers: So I am indeed quite honoured to be here because in some ways I am here despite myself. I shouldn't be here, I get to sit in the audience and listen to you all talk about my brain, my amygdala, and my pre-frontal cortex and all that dopamine and those nucleus accumbens...see, I'm getting good at this. Last year a teenager started living in my house, my oldest son Henry. So my son Henry and I went on his 13th birthday in October to open his first savings account.

The personal banker wanted to know my full name (William Pope Moyers), he wanted to know my social security number (05356); and he wanted to know where I worked (the Hazelden Foundation). Everybody in that part of the country, they know what we are and what we do there. We've been there since 1949 and it's one reason why locals know Minnesota not as the land of 10,000 lakes as the state model proclaims, but really as the land of 10,000 treatment centres.

And he thought he would make a little bit of small talk with me and so he said 'Oh, you work for Hazelden, you work for that place where they fix those crooked people.' 'I'm sorry?' I said. Well the banker was still smiling that personal banker smile of his, when he replied, 'You know, that place where people go to get their problems fixed...got to get their acts together, you know, learn to stand up straight, you know -- crooked people. You guys do great work there.'

I paused, and for a brief moment I glanced at my son Henry, who was looking at me with the same perplexed look on his face that I must have had on my face. Because you see Henry knows one of those crooked people and so do I.

So I replied to the banker, 'Oh, those crooked people! You mean somebody like me.' I was addicted to legal and illegal substances, I was sick with a disease of addiction. I stand here before you to speak out and stand up for crooked people.

I am an alcoholic, I am a drug addict in long term recovery from a 20-year love affair with alcohol and other drugs. Science tells me I have a disease. I did not ask for it but I have learned that if I don't take personal responsibility for living with this illness, then I shall surely die from it. Because while there is a solution to my disease, there is no cure, at least not yet.

Natasha Mitchell: William Moyers. A whopping TV series called Addiction has just been screened on USA's HBO network. Star of the show, Dr Nora Volkow, she heads up the National Institute on Drug Abuse, they're powerful, they fund 85% of all research on drug addiction in the world.

And while we're name dropping, Volkow is Tolstoy's great-grand-daughter.

Her findings that drugs cause major adaptations in the brain's reward circuitry have been instrumental in redefining addiction as a brain disease.

Drugs cause a surge of your brain's pleasure chemical, or neurotransmitter called dopamine, but that's not all they do.

Nora Volkow: Yes it's a disease of the brain in as much as the brain is the main target, but it's not just one little brain region that is abnormal; there are multiple circuits that appear to be involved and disrupted in people that are addicted. What happens with the process of addiction is that increases in dopamine and the pleasurable response is what seduces the person to take it again.

But it's certainly not what determines the compulsive use and the loss of control. It's what initiates a series of adaptations that then trigger the clinical presentation of addiction, which is that compulsion of using the drug, despite its catastrophic consequences.

So it's almost like it has become an automatic process in these people's lives that is very devastating, because they cogitatively don't want to take the drug and they come to recognise that they don't have control over their own behaviour.

Natasha Mitchell: So we understand when someone takes an addictive drug they get a surge of dopamine initially. But what's happening in the frontal lobes so that their whole decision-making processes, their rational mind shifts and goes AWOL?

Nora Volkow: Well what happens is that the dopamine system regulates the limbic areas of the brain but it also regulates the frontal cortex. And the frontal cortex is what assigns value to stimuli and it allows us to make decisions on the basis of their values and their consequences. When drugs produce such a gigantic change in dopamine -- much greater than any single natural reinforcer -- your brain starts to adapt because it cannot tolerate extreme changes.

And as a result of that the normal responses to stimuli become so small that you no longer perceive them as pleasurable and the only signal that is strong enough to maintain your behaviour and motivation is the drugs of abuse.

These plastic changes that lead to the resetting of thresholds of what you consider pleasurable or valuable are done at the level of the frontal cortex.

Natasha Mitchell: But your own research and others have made very interesting observations about what happens to the dopamine system in the brain in long term, in chronic drug abusers.

Nora Volkow: What we and others found is that with chronic drug administration the dopamine system, which is the one that's started by drugs, become hypo-functional. It decreases its activity when the person is not taking the drug, so when they are not taking the drug they are completely unmotivated, they don't have any desire and they are much less sensitive to stimuli.

Because dopamine regulates the frontal cortex, processes that may be very elemental like cognitive activity -- to be able to call several thoughts into your brain at the same time you need the frontal cortex, and this is regulated by dopamine.

So your cognitive operations start to get disrupted. Also the frontal cortical area involved with controlling your emotions; you want very much that chocolate chip cookie but you know you shouldn't take it, so if it's not functioning -- guess what, your ability to control that desire is going to be impaired.

So then the other element too is something that may be very valuable when you're hungry, like a chocolate chip cookie, loses its value once you've eaten two or three of them. And that ability to change the value of one reinforcer to the other is the frontal cortex. If it's not functioning properly what happens is you become fixated, and the drug abuser cannot experience the pleasure from things other than the drug.

Natasha Mitchell: Still the majority of people don't become addicted who use drugs, so do we have any sense of the neurobiology of vulnerability?

Nora Volkow: Well we've come to recognise that there are genes that are likely to play a very important role in the differences in vulnerability among people to become addicted to drugs. We do not know what those genes are, there have been several stories and we have an idea what type of gene is likely to be involved in the vulnerability. We know much more about what genes may protect you, but it is likely that a significant portion of the differences of vulnerability are related to genetics.

Natasha Mitchell: Dr Volkow, how do you see this work trying to uncover the neurological mechanisms of addiction, channelling in to therapeutic options for people, because that's the key question for listeners?

Nora Volkow: That's a very important question because obviously if we can identify which areas of the brain are disrupted by drugs, then we can target treatments and evaluate whether in fact we can improve their functioning. And this pertains both for medication but also very importantly for behavioural interventions.

So for example we've shown that the frontal cortex is disrupted in people that are addicted to drugs and this is likely to account in part for the problem they have in exerting control over their desire to take the drugs. So could we do a treatment, the equivalent of exercise, to strengthen those circuits? Documenting the type of abnormality can guide us on strategies that can strengthen or try to restitute the function of those areas.

Natasha Mitchell: Dr Nora Volkow, director of the National Institute on Drug Abuse in the USA, where a Senate bill is proposed, to change its name to the National Institute on Diseases of Addiction. Called the Recognising of Addiction as Disease Bill 2007, it doesn't impress psychiatrist Dr Sally Satel. She's author of PC MD: How Political Correctness is Corrupting Medicine and Drug Treatment: The Case for Coercion.

Sally Satel: Well I'm a clinician, I treat people with heroin addictions in particular, and I find that the brain disease formulation is just not a very useful way to think about addiction or to approach patients.

Natasha Mitchell: Sally Satel thinks research into the neurobiology of addiction is definitely worthwhile. But in a controversial article in Slate magazine, she and psychologist Scott Lilienfeld argue that focusing on addiction as a brain disease sends a perilous public health message.

Sally Satel: Because foremost, it obliterates the fact that much of the addictive process is actually under personal control. I realise that may sound counter intuitive because the very nature of addiction is a compulsion that one has trouble stopping. But the key word there is has 'trouble' stopping as opposed to being, you know, an automoton enslaved by a substance.

We have an image of the heroin addict as someone who is perpetually nodding out or in a frenzy of withdrawal and then committing crimes to get money to get his next fix. Sure, that does describe some of them. But the vast majority actually are living life, they have families, do work and they are not perpetually in a state of withdrawal and craving.

They are functional during those long stretches in between, and one of the decisions they can make -- and it's a decision my patients clearly have made -- is to get help. And we are not paying enough attention also to people who get better on their own and stop on their own; they are actually the majority of people but clinicians will not see them.

William Moyers: In the late 1980s I got swept up in the crack epidemic that washed over New York City. By the way, my disease is not an excuse but it is an explanation. My brain craved crack. By that point I didn't do it because I enjoyed it, I did it because I needed it.

My body thirsted for it, my soul was soothed by it. I smoked cocaine until I couldn't stop no matter what. I consumed it until it consumed me.

Then in 1989, as I said, I hit bottom, I was locked up in the psyche ward of St Vincents Hospital in New York City.

Being locked up seemed to make perfect sense to me because indeed I was insane; my brain had been hijacked, my body had been robbed, my soul had been smothered by my insatiable appetite to binge on the very substances that were killing me despite the consequences -- financial ruin, bad health, failed marriage, insane thinking and all that stuff -- I still had a craving in that brain somewhere which I did not understand, I just felt it, I couldn't explain it.

Continued in the All in the Mind transcript.

William Moyers is author of Broken - My Story of addiction and Redemption.