The Addictive Brain as taught by Professor Thad A. Polk Part V

This is the final post of the review of The Addictive Brain. Please see part one dated 12/5/2016 and scroll upwards for the subsequent parts. The last two lectures covers the controversial subjects of behavioral addictions.

Lecture 11: The Gambler’s Brain

Gambling behavior often mimics drug addiction behavior. Obsession to gamble despite severe personal and social consequences. A very high percentage of people have experienced gambling but the vast majority don’t develop problems. 4 – 6 million americans experience problems due to gambling. About 2 million meet criteria for pathological gambling. The 5th edition of the Diagnostic and Statistical Manual, the bible of psychiatry, classified pathological gambling along with the behavioral addictions. Was classified as impulse control problem such as kleptomania in older editions.

Behavioral similarities to drug addictions:

1) Recurrent substance use, or gambling resulting in failure to perform major role responsibilities at work, school or home.

2) Jeopardized or lost a major relationship or job or career opportunity due to gambling.

3) Persistent desire or unsuccessful efforts to cut back, stop or control gambling behavior.

4) Continued gambling despite significant negative consequences.

In a sense tolerance develops to gambling. The problem gambler often needs to wager larger amounts or go for larger jackpots to get the same rush of excitement he used to get with gambling smaller amounts. They do have symptoms with withdrawal. 91% of problem gamblers experience craving upon withdrawal. 87% feel restless and irritable. 2/3 of people reported physical symptoms like headache, insomnia, shaking and sweating.

Brain changes in addiction to drugs are mirrored in gamblers brains:

1) Numbing in the Nucleus Accumbens so things besides gambling don’t give pleasure.

2) Large releases of dopamine in the reward circuits of the brain. Eventually leads to cravings and triggers.

3) Chronic use results in reduced self control in the prefrontal cortex.

Twin studies show that problem gambling are heritable. Problem gamblers often have alcoholism.

Some of the same approaches in drug addiction are helpful in gambling addiction. CBT and social support like 12 step groups help. Naltrexone effective in reducing gambling behavior.

Lecture 12: Junk Food, Porn, Video Games – Addictions?

Dr Polk starts by reminding us of the shared characteristics of addiction. Genetic susceptibility of some. Similar patterns of neural rewards and reinforcements. Continued addictive behavior despite significant negative consequences. In this lecture he wants to talk about 3 behaviors that people seem to pursue compulsively: Junk Food, Pornography and Video Games.

This is a grey area and scientists don’t all agree these behaviors constitute a true addiction. It is safe to say that many people do have trouble with these behaviors to the point of it adversely affecting their lives.

It’s important to understand the concept of supernormal stimuli. We are naturally attracted to sweet foods. In nature they are found in fruits. When you refine sugar and make “super sweet” desserts we naturally are attracted to the supernormal sweet. Intense sweet foods that don’t exist in nature. You can make the point that all three of the above are supernormal stimuli. Our reward circuits were evolved to give us pleasure in eating natural sweets so they are super stimulated by the supernormal sweets.

The same logic applies to sex. We are highly motivated to seek the pleasure of sex but sexually provocative stimuli in the natural environment is rare. Porn and sexually provocative stimuli are now common.

Video games have progressed a lot since Pong. We now have sophisticated graphics and gamers get immersed in elaborate fantasy worlds. It’s also big business. In the first 3 days the latest Grand Theft Auto made over a billion dollars. There is a scientific consensus that video gaming can become compulsive in some individuals. One study showed that about 8% of a study group had pathological gaming. Gaming that was causing problems and interfering with their life.

Michael Astolfi, a video game designer, wrote a thesis at NYU claiming video games have stimuli that are supernormal. Mainly that we may have evolved to be hunters and video games overstimulate our hunting instincts. Many of the popular games are first person shooter games. In real hunting you maybe take a shot once in a day or so. With video games you take shots every second or two or even more rapidly. Thus getting your reward system over stimulated.

Neuroscience studies for behavioral compulsions are in their infancy but the lecturer points out that some studies have shown that these behaviors increase dopamine in the brain reward circuits. Even the pattern of the reward centers getting numbed to chronic stimulation from these behaviors is present.

For treatment the individual has to recognize that they have a problem and want to improve their behavior. Cognitive behavioral strategies help along with social support networks.


Dr Polk then did a couple of minutes of summary of some points.

1) Addiction is defined as the continuation of a behavior despite significant consequences. Characterized by abuse, physical dependance and a pathological craving.

2) Some people are genetically more susceptible to addiction. There is not a single addiction gene. There seems to be a large number of genes involved and just because someone is susceptible doesn’t mean they will become an addict.

3) The brains of an addict are different from the times before they started using or drinking. The reward system has been hijacked and rewired to produce pathological craving, numbing of the reward centers and weakening inhibitory self control.

Understanding the biological basis of addiction helps us understand the seemingly incomprehensible behavior of some addicts such as the alcoholic with cirrhosis continuing to drink. Also understanding this helps us approach the addict with compassion and understanding instead of judgement and criticism.



One thought on “The Addictive Brain as taught by Professor Thad A. Polk Part V

  1. Hi Steve. I listened to this course with interest and think you have a great summary. I’m also jealous to see you’ve watched The Business of Recovery already – it’s not available here in the UK yet. Anyway just wanted to touch base and say hi after I saw your piece in AA Beyond Belief. I’ve also been interviewed there and done a blog. Not sure if you’ve seen it but thought I’d mention it as we have a similar experience. Best wishes and thanks for all the good work. JS

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