Science writer Dirk Hanson takes readers on a journey of understanding about addiction in The Chemical Carousel: What Science Tells Us About Beating Addiction. In a conversational tone, Hanson acts as teacher and storyteller as he sheds considerable light on the still-largely unknown field of addiction science. Some may wonder that there actually is such a field, but it is gaining traction every day, thanks to advances that are nothing short of ground-breaking.

Motivated by a personal experience with heavy drinking – and being able to quit – Hanson dove into research about what makes a person an alcoholic or a drug addict, what causes him to become sober and remain so, and why can’t some addicts ever get off the vicious cycle of addiction. This actually fits quite well with the title, since a carousel keeps going around in a circle, and addiction does the same (unless the addict gets treatment and gets off the circular pattern of behavior).

The capsule version of what the book is about appears in Hanson’s own words: [It’s] “the story of what happens to a molecule of cocaine, or a molecule of gin, or a molecule of THC, after it wends its way inside the human brain. Once that has happened, an alchemical combination of molecular messengers – serotonin, dopamine, norepinephrine, glutamate, corticotrophin-releasing factor (CRF) – operate at specific receptor sites, especially in the portion of the brain known as the limbic system. Everything that follows, from behavioral problems to broken marriages, from jail time to rehab is a result of changes in infinitesimally small amounts of these chemicals in the brain.”

Image that. Addiction all boils down to a mix-up and interplay between brain chemicals due to an influx of molecules from an addictive substance. Sounds simple enough, doesn’t it? If only it were so easy to dissect, addiction science would be a lot farther along today than it is. The complicating factor – and there are many – is that there is no single blueprint, no universally-identifiable pathway and firing or misfiring of neurotransmitters that is responsible for all addiction. The interplay is different in alcohol addiction versus heroin addiction, in methamphetamine addiction versus nicotine addiction, in addiction to prescription painkillers, inhalants, marijuana, and all the rest.

Genetic linkages have been found that play a role in a person’s predisposition – but not predestination – toward addiction. Environmental factors also loom large in whether one person in a family with alcoholism becomes an alcoholic as well or is able to overcome the influence of the alcoholic’s self-destructive behavior and role-modeling.

But back to the book and what it’s all about. Hanson divides the book into four sections, each more or less a self-contained read. Some of the terms are a little foreign and take getting used to for the average reader not well-versed in medical and scientific jargon. But you get the general gist of the message fairly easily. Best of all, it’s written in such a way that you can’t really get lost. Just re-read a paragraph if you’re distracted, or need clarification. Then, keep on reading. Everything will start to sink in.

Part one is all about a history of drug use and abuse, with a special emphasis on genetic studies. Chapter one, “The Alcoholic Rats of Dr. Li” is particularly enjoyable. Think Pavlov’s dogs and conditioned response and you’ll get an idea where this goes. Part two is an in-depth look at the drugs themselves. Ever want to know how drugs do what they do? You’ll find it in this well-written section. Hanson discusses alcohol and heroin, nicotine and caffeine, stimulants, marijuana, and carbohydrates. Part three concentrates on the drugs available for treatment as well as the emergence of new, anti-craving medications, what the author calls “fighting fire with fire.” Part four delves into alternative approaches to addiction, including self-help groups such as Alcoholics Anonymous, to the long-standing war on drugs, to an approach called harm reduction. There is also a comprehensive notes section, selected bibliography, and index.

Reading through the book, you get caught up in the science aspect. Two plus two doesn’t always equal four – sometimes it equals eight, confounding logic. This refers to the fact that addiction is a complex disease. Treatment sometimes requires years and many different modalities or treatment approaches. Relapse is common and, although it may one day be preventable, we’re not there yet. Often addicts move two steps forward and one step back, or treatment and recovery in not an altogether linear fashion.

In the final section discusses the merits and pitfalls of legalization, neo-prohibition, and decriminalization of drugs in the United States. These discussions tend to be controversial, so some readers may be put off by the author’s strong bias. However, he presents the arguments for each in a fair and more or less balanced way. It certainly does seem appropriate that he points out how much off kilter the expenditures are for interdiction of drugs and those who manufacture, deal, possess and use them versus funds available or targeted for prevention and treatment. Fortunately, Hanson sums it all up with a statement that “Addicts, and those who love them, are beginning to discover that the biochemical models of addiction are profoundly empowering notions all their own. They stand against denial, and lead in the direction of treatment and recovery. No other approach holds out such promise.”

For an enjoyable read by an author who has very much done his homework, this is one book that’s definitely worth a look. If nothing else, readers will remember Dr. Li’s alcoholic rats… As to whether an addict can get off the chemical carousel, and will it be anytime soon – the answer is, as always, maybe and that depends. Beating addiction takes grit and determination, adequate treatment, possibly medication, and time – lots of time.

Hanson’s book is available for purchase through Amazon.  Hanson also maintains a great blog on the science of addiction.