The Biology of Desire (Marc Lewis)

Written by Fred Toates on .

Marc Lewis

Public Affairs, New York. 2015

From the responses on Amazon USA, it would seem that you either love or hate this best-selling book. I will suggest why this might be so in a moment. I am in the love camp, which forms the majority. For me, this is very well-written and blends beautifully the personal accounts of people who have experienced addiction with an understanding of the underlying neuroscience. The two-pronged approach, involving often distressing accounts of the suffering of addicted people, is necessary in order to gain a full picture of the nature of addiction. The author cuts very skilfully between neuroscience and his compassionate treatment of the insightful autobiographies, such that the various features of addiction can be linked to what is happening in the brain.

A number of such features of addiction described include:

These features are explained very well, always being linked to the personal angle. Although the bulk of the book is devoted to addiction to substances, the author rightly notes that addictions to sex or gambling show some very similar properties to drug addiction. Hence, contrary to the vociferous arguments of some, there is no 'myth of sex addiction'. It is real.

The book is written in a very clear style with a rich sense of humour and it could be read equally well by the expert and non-expert alike. It has a particular weight of conviction given the author's unique credentials: a respected developmental neuroscientist with his own history of drug addiction. The author rightly dismisses the kind of all-or-none bizarre logic that, if the brain is involved in addiction, then it must be a disease. The brain is bound to be central to addiction. An addicted brain is a changed brain but, in Lewis' opinion, that is not synonymous with a diseased brain. Misguided 'social versus biological' dichotomies rightly have no place in this book.

The central and controversial argument of the book is that the term 'disease' to describe addiction has outlived its usefulness, though the author notes that this is at least better than descriptions that suggest that addicts are simply weak-wiled or sinners. Somewhat in the spirit of humanistic psychology, the author argues that the medical model encourages passivity, rather than persuading addicts to make a life-review, to try to change their priorities in life and to anticipate a better future.

Addiction is rather different from an unambiguous disease such as diabetes or influenza since the psychological steps that Lewis suggests would hardly be likely to cure such conditions. It might appear then the author is in the camp of those who believe addiction is a so-called free-choice but he also rejects this model. No one freely opts for a career trajectory as an addict but that is not to deny some agency. For example, a large number of US soldiers in Vietnam were hooked on heroin but the prospect of a return home was enough to persuade them out of their habit. It seems to me to be a question of the psychological pain that is felt in refraining from the habit, rather as it is for obsessive compulsives in not engaging in, say, hand-washing. In this sense addiction is different from an automatic reflex.

I follow the author's logic but I wonder whether we are simply bedevilled by the problem of the social construction of language. That is to say, words do not necessarily convey an unambiguous meaning that is divorced from the goals and agenda of the user. For some purposes, it might still be useful to see addiction as a disease; as the author acknowledges, this helps to keep research money coming in and triggers sympathy rather than punitive measures. However, the situation might do a sudden flip whereby, in the spirit of this book and like the flip from seeing a rabbit to seeing a duck in an ambiguous figure, the word 'disease' is a very dangerous hindrance to progress. The author emphasises that addictions are examples of learning and habit formation. By the same token, I was led to speculate whether he would resist the use of the term 'disease' (or 'dis-ease' or 'illness') to describe depression, anxiety, obsessional disorder and post-traumatic stress disorder, since learning is doubtless of central importance there too and in some cases mindfulness meditation can help. The author told me "You're quite right that the problem doesn't go away when we consider other mental HEALTH issues, such as depression and PTSD. I would never call those diseases, per se....but once you get to bipolar disorder, the distinction becomes seriously blurry" (Lewis, personal communication).

Depending upon various circumstances, obesity might be treated as a disease by the use of gastric surgery or as a bad habit, a learning problem, by a switch of diet. Which of these is correct? It all depends. Could there be some addicted people for whom it is all too much to try to project into the future to an addictionfree existence and where the label of disease is comforting, whereas doubtless there are many others who would be lifted out of the pits of despair by following the message of this book? If so, I don't know how we might distinguish these two groups in advance. A doubleblind study of efficacy would be useful but the practicalities of doing so are formidable. Those who find the disease label a comfort might well not like this book, whereas those who have found their salvation through following this or similar messages would probably give it 5 out of 5 stars on Amazon.

Concerning brain changes accompanying addiction, I would micro nit-pick with the claim on page 42 that: "These changes don't result from addictive substances. They are not caused by booze or drugs." Surely they are partly caused by the substance but acting in combination with the environment and the hedonic experience. The substance needs to occupy receptors for the course of drug addiction to be set initially. After that, the addict might get high on any arbitrary substance in the belief that it is the target drug. This is evidenced by the phenomenon termed 'needle-freak', where addicts can get high on placebo injections. One assumes that the casino, prostitute or porno movie has its effect in part by means of triggering chemical changes in the brain that are similar to those triggered by addictive drugs. Similarly, on page 52 the author writes "For Natalie, it wasn't drugs in general, or opiates, or even heroin that changed her life. It was the practice of shooting up." Again I would suggest that it was the combination of the chemical changes in the brain AND the motor act and associated cues that changed her life.

To conclude, this is an exceptionally valuable and provocative book written from the heart, which is likely to be of great help to sufferers and those who treat them, as well as students of addiction.