Chemical warfare
YOU may not have heard of dopamine but the chemical plays an important role in our lives. It’s there in the sigh of pleasure as we sip cold white wine; at the end of a long day. it’s there when we tuck gleefully into a bowl of hot, creamy pasta; it’s there when we have sex, and when we shop; buy something new at the shops and when we win big at the horses. Dopamine is a key chemical component of the ‘feel-good factor’. But there’s more to it. Experts say it has a dominant role in how people become addicted.
“Dopamine is one of 60 or so neurotransmitters in the brain and one of the main transmitters on the brain reward pathway, also known as the mesolimbic dopamine system,” says Professor Carlton Erickson, the director of the addiction research centre at the University of Texas, who is speaking at this week’s Neuroscience and Evidence-based Practices for Addiction and Recovery (NEAR) Conference in Co Wicklow.
This conference will bring together a panel of national and international experts to deepen our understanding of what addiction actually is and what can be done to treat it. Professor Erickson’s talk will focus on the latest discoveries in relation to dopamine and the implications for how addicts can be helped to recover in the future.
“Dopamine plays a major role in the functions of the brain involving mood, muscle control, the ability to experience pleasure and perhaps other functions we don’t even know yet,” he says.
“What we do know is that any time a person experiences a pleasurable event — whether it’s eating, winning a bet, attending a wedding or the birth of a new baby — this pathway fires and results in that person feeling good.”
At a chemical level, dopamine travels along the mesolimbic dopamine system until it arrives at the dopamine receptors. These receptors translate the dopamine into a feeling of pleasure and send these pleasurable nerve signals to the frontal lobe, the area of the brain that takes decisions and controls impulses and judgement.
Once it has received a sufficient amount of these signals, the frontal lobe decides when enough pleasure has been experienced. This is what causes you to stop drinking, eating, having sex, shopping or gambling.
Or not, as happens in some cases. “What we have discovered is that something goes wrong with the reward pathway in the addictive brain,” says Professor Erickson.
“The pleasurable nerve signals being sent to the frontal lobe are misinterpreted as encouragement to continue using the chemical, even though adverse consequences may either be looming or actually occurring. Put simply, addictions are the result of our brain losing the ability to recognise when it is time to stop.”
Because alcohol has been the most commonly-used addictive substance in the past 25 years, most of the research in this field relates to it.
“We have found that in the case of alcohol, up to 60% of addicts had a predisposition to alcohol dependency,” says Professor Erickson.
“This means that they had a faulty pathway and faulty dopamine receptors. This was a significant factor in their developing an addiction.”
Although it has yet to be scientifically proven, experts such as Professor Erickson say that there is a genetic basis to this predisposition. People are likely to be born with faulty dopamine receptors.
It’s not just those who are born with faulty dopamine receptors who develop problems. The brain’s reward pathway can also be changed by continued exposure to addictive substances.
“Drinking a lot can cause the dopamine receptors to adapt and begin to react in an improper way,” says Professor Erickson. “This process of neuro-adaptation also results in the dopamine receptors sending the wrong message to the frontal lobes and ultimately results in addiction.”
Professor Erickson says that a faulty reward pathway and damaged dopamine receptors constitute the difference between substance abuse and addiction.
“Abuse is what we see in pubs on Saturday nights,” he says. “These are people who choose to drink too much. They can control their condition and their consumption can be reduced by education, punishment, maturity or increased willpower. But in the cases of addiction or dependency, there is no choice there. They simply have to drink more and it will usually require powerful intervention and intensive treatment if they are to stop.”
This medical model of understanding addiction is only proven in the context of alcohol dependency, but Professor Erickson is convinced it is true of other forms of addiction too.
“It could explain dependency on drugs and other compulsive behaviour such as shopping, excessive internet usage and overeating,” he says. “But the research just isn’t there to prove it definitively, at the moment.”
In the US, the treatment of addiction has adapted in line with these new discoveries. But it hasn’t changed as much as you might expect, or even in the way you might anticipate. “You might think that addiction medicine would be a magic bullet in dealing with a faulty mesolimbic dopamine system,” says Professor Erickson.
“But I’ve seen people in the Betty Ford Centre. I’ve heard their stories, observed their therapies and seen the outcomes. From what I’ve seen, it’s best to use medical treatment in tandem with some sort of talk therapy, such as cognitive behaviour therapy, psychiatric counselling or a 12-step programme. It’s the combination of the two that seems to make people better.”
If that’s what is happening in America, what of Ireland? What difference has the advancement in the understanding of addiction made to the treatment on offer here? The approach taken by the staff of Toranfield House, a residential rehabilitation clinic that opened in Wicklow two years ago, closely follows the American model advocated by Professor Erickson.
“We don’t see opiate addiction, alcohol addiction or gambling as separate diseases,” says the CEO and MD of Toranfield House, JC Durbin. “We see addiction as a syndrome that manifests itself differently in different people. It’s all based on the brain’s reward pathway. Any behaviour that triggers this pathway can cause a craving and lead to a subsequent addiction.”
If JC Durbin and the staff of Toranfield House agree with the science behind addiction, do they also follow the same form of treatment? Do they combine medicine with therapy?
“Our approach is what I call a humanist integrated one that allows for medical treatment and focuses on behavioural treatment,” says Durbin.
What this means is that residents at the facility attend group-counselling and individual-counselling sessions and their use of medication, such as antidepressants and other drugs, is supported as long as they are proving efficient in terms of their recovery.
This is not an easy process, especially as addiction in Ireland appears to be changing, says Durbin. “We know that Ireland has a long-standing problem with addiction,” he says. “But what we’re seeing now is much more complicated than it used to be. Very few clients come to us with just one issue.
“If they’ve got issues with alcohol, they’ve also got problems with gambling. If they’re overeating, they might also be compulsive shoppers. It’s no wonder, really, considering the multi-generational trauma people have undergone in this country.”
Addiction treatment is a long-term process as well as a complicated one. If it is to be successful, there must be proper aftercare in place. Every client of Toranfield House receives a year of aftercare after they leave the facility.
“It’s generally accepted that it takes three to five years to stabilise after addiction and become healthy,” says Durbin. “It’s the same as doctors saying that you are not in remission from cancer until you’ve been cancer-free for five years.
“This is why we encourage our clients to continue to come to the centre for weekly group therapy sessions for a year after they leave.”
If Toranfield House is close to Professor Erickson’s model of addiction treatment, the Rutland Centre in Dublin differs in some aspects.
Dr Fiona Weldon, clinical psychologist and clinical director of the centre, doesn’t hold with the theory that all addictions are the same.
“We have seen that there are certain characteristics that are common to all kinds of addiction, such as keeping your addiction secret, isolating yourself and the addiction taking over your life,” she says.
“These are the similarities but there are differences too. That is why we follow individual care plans that focus on group and individual therapy and that are based on psychiatric assessments.”
Like Durbin, she has also noticed a change in the type of people presenting themselves for help.
“Gone are the days of having one particular addiction,” she says. “These days, people present with several, such as alcohol and cocaine, for example.”
This makes treatment all the more difficult as the effect of the interaction of these substances on a person’s physical and mental health, as well as on their brain function, is hard to anticipate.
“It means that we have to tailor our treatment all the more,” says Dr Weldon.
While the advances in the scientific understanding of addiction, and the role played by dopamine, have yet to make much of an impact on the forms of treatment employed at the Rutland Centre, Dr Weldon says that this knowledge should be shared with the public.
Weldon says it’s vital that people be told about the impact their substance abuse might be having on their brains.
“People need to be educated,” she says. “They need to realise that what they are doing can cause organic damage. There can be a long-term effect of stimulating chemicals in the brain. The dopamine system needs to be balanced, and if the receptors are damaged, it can lead to long-term depression. People need to know that they can reach a point of irreversible damage.”
We are at a very early stage in our understanding of the science behind addiction, of the role played by dopamine and dopamine receptors, and how this knowledge can be used in future treatment. But Professor Erickson is hopeful that the latest discoveries in relation to the mesolimbic dopamine pathway will encourage governments to invest more in research.
“The way we are treating people is based on our understanding now,” he says. “It might have all changed in five or ten years’ time.
“Until now, governments have seen addiction as a personality or willpower problem, a problem the individual had to solve on his own. But if they understand that it can be genetic and that there is a scientific basis behind it, that addicts really have no control over what they are doing, they might change their attitude and increase funding.
“The reason we don’t know as much about addiction as we do about cancer or heart disease is because we haven’t spent as much money on it. With more funding, we’ll be able to understand addiction better and treat it more effectively.”
The Neuroscience and Evidence-based practices for Addiction and Recovery (NEAR) Conference will take place in the Ritz Carlton in Enniskerry, Co Wicklow from Thursday, November 10 to Saturday, November 12.
See www.nearconference.com for more details.
* The Science of Addiction: From Neurobiology to Treatment, by Carlton K. Erickson
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