The devastating effects that drug addiction has at many levels of society is unequivocal. So is, I would argue, the evidence that addiction is a disease and should therefore be treated as such.
Disease reflects the underlying dysfunction of some aspect of the body. In type 1 diabetes this can be clearly traced to a deficiency in insulin production. In addiction the cause is admittedly more obtuse, but the fact that the underlying cause is complex does not in any way negate the fact that drug addiction is a disease like any other, with corresponding neural dysfunctions which must be treated.
The persistence of the view touted by Peter Hitchens and others that drug taking is always an action of free will and that people only ever take drugs ‘because they enjoy it’ is naïve and demonstrates a blatant ignorance of the overwhelming evidence that neural pathways mediating reward, choice and emotion are profoundly damaged in individuals suffering from addiction.
So what are the changes that occur in the disease of addiction? Addictive drugs have diverse effects in the brain but all share one feature in common – they raise levels of dopamine in emotional (limbic) pathways involved in reward. This release of dopamine produces feelings of reward so strong that monkeys given the opportunity to freely self-administer cocaine will do so continually until they die, ignoring both food and water (Deneau 1969). The effects of cocaine are thus incredibly powerful and simply choosing to stop taking a drug is clearly not quite as easy as Mr Hitchens suggests.
In addition to this powerful reward effect, there are also many longer term drug induced changes in the brain that result in a further inability to cease drug taking. The body’s compensatory response to the effects of a drug result in withdrawal symptoms when an addict attempts to quit. These will be exactly opposite to the effects the drug has e.g. withdrawal from heroin will be felt as depression, cramping, diarrhea and agitation. Withdrawal symptoms make it very difficult to quit, because normality for an addict comes to necessitate the drug, and without it, daily life can become rapidly unbearable. So addiction profoundly alters an individual in such a way that quitting becomes nigh on impossible without external help.
To make matters worse, the brain of an addict becomes distinctly less able to make rational judgements or exert control over impulses. This is due to dysfunction of pathways between the frontal cortex and the aforementioned emotional (limbic) centres of the brain. The prefrontal cortex is what distinguishes humans from other animals and its slow development compared to the rest of the brain explains the impulsivity and risk taking behaviours seen in teenagers. A kind of internal parental influence, enabling you to make decisions rationally and control impulses. Addictive drugs hijack this master controller to place themselves at the top of the motivational priority list and block out the sensible rationality of the prefrontal cortex. They can be assimilated therefore, to parasites that take hold over their victims to make them obtain more and more, whilst also eroding their ability to fight off the disease and say no. This is why an individual will continue with the habit despite the fact that it is ruining their health, relationships, financials and career.
Helping individuals to overcome their struggle, with medication and therapy, is therefore essential. As opposed to the alternative ‘treatment’ of placing addicts in a prison cell where, if anything, an addiction will be further cemented and previously productive citizens will becomes isolated and criminalised. Substituting the drug for less potent and less addictive substitutes such as buprenorphine (to replace morphine) works well to wean an individual off the drug and reduce the impacts of withdrawal. An effective treatment for alcoholism is disulfiram which reacts with the alcohol to produce hangover like effects immediately after drinking so as to entirely abolish the positive effects of the drug and to make the consequences of taking it more immediately averse than not taking it. Other methods for treating addiction strengthen the saliency of natural rewards by increasing dopamine release. A potential avenue for the future is antibodies that bind to and prevent the drug from entering the brain, thus blocking any positive effect.
I would like to stress, that whilst addiction is clearly a disease that needs medical treatment not punishment, this does not absolve an individual of any responsibility regarding addiction. As Dr Volkow points out: ‘People say if you consider drug addiction a disease, you are taking the responsibility away from the drug addict. But that’s wrong. If we say a person has heart disease, are we eliminating their responsibility? No. We’re having them exercise. We want them to eat less, stop smoking. The fact that we have a disease recognizes that there are changes, in this case, in the brain.’
So whilst the decision to first take a drug is clearly a choice, the addiction that takes hold thereafter is a disease and I defy those who suggest they can prove otherwise.