As clinicians we know that the sex addict doesnt fall too far from the family tree. Or as a friend of mine put it: Sex addiction comes barreling down the generations like a locomotive!

So addictions run in families, but what part of this is due to genetics, to life experiences, and to other personality variables? And can the genetic research on other addictions be applied to sex addicts?

Researchers have been investigating the genetic factors in drug and alcohol addiction for many years using identical twins vs. non-identical twins. It is reported that approximately 50% of the predisposition to addiction was accounted for by genetic factors. More recent studies use brain science and genetic factors to help understand why addiction is heritable.

Where genes come into play

According to a 2008 review entitled Genes Matter in Addiction, researchers using brain imaging concluded that genetic differences accounted for the number of dopamine receptors in the brain. This could be used to predict whether someone would become addicted to drugs or alcohol, meaning fewer dopamine receptors is related to vulnerability to addiction.

However, these researchers broke the addiction process down into three parts: (1) experimenting with drugs, (2) repeatedly using drugs, and (3) becoming addicted to drugs. They found that it is at the point after repeated use that genetic vulnerability begins to determine who winds up addicted. In other words, prior to repeat usage, other factors may have a greater influence. But overall, children of addicts have been reported to be eight times more likely to develop addictions.

Brain chemistry and genetics

Regardless of genetic makeup, drug usage has the ability to rewire the brain to strengthen the power of the chemical in question to activate the reward system in the brain. Genetic make-up evidently has the potential to kick the process over into addiction more readily.

According to the data summarized in the 2008 article, the genetic connections are particularly strong for smoking. Genetics account for about 75% of the likelihood of beginning to smoke, 60% of the tendency to become addicted and 54% of the probability that you can quit.

All addictions seem to work the same

If your genetics are such that you are predisposed to addiction, that predisposition applies to all addictions. Since they all operate in the same areas of the brain, a family history of addiction renders you more susceptible to any addiction. This is why abstaining from one addiction can result in the emergence of another, which in turn can trigger a relapse of the original addiction.

This tendency for addictions to substitute for one another means not only that addicts need to quit all potential drugs of abuse but that they need to address the deeper causes, the other 50% of determinants beyond the genetic ones in order to stay sober.

Relevant personality factors are heritable as well

A paper from 2005 reports on the use of more refined mapping of genetic markers to analyze specific inherited personality traits that contribute to the genetic predisposition for addiction. In particular, impulsivity, risk-taking and stress responsivity. The authors conclude that:

Addiction is a complex disorder with interacting factors, including environmental factors, drug induced neurobiological changes, comorbidity, personality traits and stress responsivity.

Important implications for sex addiction and other addictions

In one 2012 report from the University of Bonn researchers have been able to link the genes associated with smoking with internet addiction as well. Online addicts were compared to non-addicts. The addicts more often carried the same gene variant as the smokers. The genetic studies to date have important implications:

  • Although the neurobiochemistry of addiction may rest on normal brain processes, the existence of addictive gene variants has the potential to further support the disease model of addiction
  • The research supports the idea that the genetic findings for drugs, alcohol and nicotine are applicable to other behavioral addictions as well including behavioral ones like sex addiction and porn addiction.
  • Increasingly sophisticated studies of the genetics of addiction will allow us to diagnose and treat and ultimately protect against all addictions with far greater specificity.