Can Genes Influence the Severity of Substance Abuse?

A recent study by the Brookhaven National Laboratory found that drug-addicted individuals who have a certain genetic makeup showed lower gray matter density (and therefore fewer neurons) in areas of the brain that are crucial in decision-making, impulse control, learning and memory. As a result, the study demonstrated that genes can influence the severity of addiction for an individual.

Using cocaine-addicted individuals and a control group, scientists took DNA samples and analyzed them for the presence of high or low MAOA to determine each participant’s genotype. MAOA is an enzyme that regulates neurotransmitters in the brain, such as serotonin and dopamine.

The cocaine-addicted individuals with a low MAOA genotype had lower gray matter density in the frontal cortex of the brain than those addicted to cocaine with a high MAOA genotype and the control group (non-addicted individuals). In addition, the study found that patterns of low gray matter correlated with the number of years drugs and alcohol were abused. The longer the substance abuse, the lower gray matter was found the the frontal cortex of the brain.

The research suggests that addicted individuals with a low MAOA genotype may need different methods of treatment than those who carry a high MAOA genotype. The researchers say more studies need to be conducted to further shed light on these neurobiological findings.(Medical News Today)

The study was published in a March issue of  the Archives of General Psychiatry.