Low Serotonin Levels Could be Responsible for Addiction

A new study conducted by Sarah Bradbury, who recently received her PhD in Psychology, has found a direct correlation between drug addiction and levels of serotonin in the brain. This study has the potential to start a revolution in addiction recovery treatment.

Serotonin helps regulate mood, appetite and sleep. Additionally, it has some cognitive functions, including memory and learning. Several classes of pharmacological antidepressants modify serotonin at the synapses. Bradbury found that a person’s serotonin levels in their first experiences with drug use play a critical role in whether they form an addiction. She also suggests that serotonin levels begin to decrease once drug use becomes more frequent. Bradbury’s research focused on MDMA and cocaine but she said that her findings translate to a much larger range of addictions.

“People develop drug addiction due to changes in specific brain systems following repeated drug use, but not all users become addicted,” she explained. “Another brain chemical, dopamine, seems to be the critical determinant of drug addiction during this phase.”

Bradbury’s findings are similar to other recent research projects. A Vanderbilt University study from December 2011 found a connection between recreational ecstasy use and sustained increases in serotonin receptor density. This can lead to major serotonin depletion and even severe depression as the drug exits the user’s system. Once the damage is done to the serotonin receptors, there is no way to fix it; the damage is permanent. Some scientists use ecstasy as a means of treating autism and post-
traumatic stress disorder but it’s an entirely different situation than using it just for fun. There’s a major difference between using the drug recreationally and using it therapeutically.

Also connected to the susceptibility to addiction is a person’s natural dopamine levels. Dopamine is a hormone and neurotransmitter that has a number of important roles in the human body and brain. Dopamine plays a major role in reward-motivated behavior, motor control, and in controlling the release of several other important hormones. A study published in July 2013 in the journal Proceedings of the National Academy of Sciences found that chronic marijuana use dampened the brain’s dopamine reaction to stimulants. This means that chronic users may experience less of a reward or motivation from things that most people find enjoyable. Contrary to the stoner stereotype, it could leave users feeling irritable, moody and restless.