addiction

Genetic Makeup and Duration of Abuse Reduce the Brain’s Neurons in Drug Addiction: Due to the research accomplished by U.S. Department of Energy’s Brookhaven National Laboratory, Brookhaven Lab, Stony Brook University, Mount Sinai School of Medicine, the National Institute on Alcohol Abuse & Alcoholism, and the National Institute on Drug Abuse, a study shows that many individuals have a particular genetic makeup that is lower in gray matter density, which supplies less neurons in certain areas. These areas are essential in decision-making, memory and self-control.

A study coauthor and Brookhaven Lab Medical scientist, Nelly Alia-Klein comments. “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.”

Proven in this study and recent ones, cocaine-addicted individuals have lower gray matter density in frontal parts of their brain. The frontal part of the brain allows a person to organize their behavior and is also important for paying attention. The study showed that cocaine-addicted individuals with a low MAOA genotype had lower gray matter density in the brain’s orbitofrontal cortex while individuals with a high MAOA genotype and who were not addicted showed higher gray matter density. MAOA genotype is referred to an enzyme that standardizes neurotransmitters in the brain that controls behavior and moods.

The study also showed that a pattern formed between low gray matter and the amount of years an individual had been using cocaine, cigarettes or drinking. The longer an individual has been using one of all of the above, the less gray matter density there was to find in the brain.

For this study 82 men were used, 40 were addicted to cocaine while 42 were controlled. They were studied for their genotype, which was processed by taking DNA samples and analyzed for high or low MAOA. The men’s brains were also scanned via a magnetic resonance imaging as well as voxel-based morphometry, which were both able to provide density of gray matter in the entire brain. Once the gray matter density was found, it was compared between the two groups and then compared to genetic type and the duration of drug use.

Klein’s explains. “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. 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.”