Genes and Addiction: Can One Influence the Other?

There is a definite link between genes and addiction and the level of a specific genotype can influence the severity of addiction.  A study conducted at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory demonstrated that drug addicted individuals who have a certain genetic makeup have decreased gray matter density – and therefore fewer neurons – in areas of the brain that are essential for decision-making, self-control, and learning and memory.  The research is reported in the March 7, 2011 issue of the Archives of General Psychiatry. 

Nelly Alia-Klein, study coauthor and Brookhaven Lab medical scientist said, “This research shows that genes can influence the severity of addiction. The results suggest that addicted individuals with low MAOA [monoamine oxidase A] genotype may need a different kind of treatment than other addicted individuals who carry the high MAOA genotype. More studies need to be conducted before implementing changes in treatment strategies. However, addiction treatment professionals and others who manage addicted individuals, such as probation officers and judges, should be informed of these and other new findings in the neurobiology of drug addiction.” (Photo and quote courtesy BMED Report)

The study found that cocaine-addicted individuals with a low MAOA genotype had lower gray matter density in the brain’s orbitofrontal cortex than addicted individuals with a high MAOA genotype or non-addicted individuals. MAOA is an enzyme that regulates neurotransmitters in the brain, such as serotonin and dopamine, which control mood and behavior.

Curtailing drug use may be protective against such brain changes.  The longer cocaine, alcohol, and cigarettes were abused, the lower gray matter was found in the hippocampus and frontal regions of the brain.

The scientists recruited 82 men – 40 addicted to cocaine and 42 controls.  “Only males were part of this study and therefore it is important for future studies to examine these genetic and brain effects in females as well,” Klein explained. “Also, further studies will have to be done to track these gene-brain-behavior patterns throughout a lifespan that influence the volume of the brain’s neurons.”