Addiction Research

Cocaine Use Shown to Speed Brain Aging

Brain aging is a general term used to describe structural, chemical and psychological changes that commonly occur in the brains of older individuals. While this process doesn’t affect everyone in the same way, aging in the brain is associated with a number of significant health problems, including Alzheimer’s disease and depression. Current evidence indicates that people who habitually abuse cocaine develop changes in their brains that point toward the onset of premature brain aging. In particular, habitual cocaine abuse can destroy grey matter, the material that forms the core of the brain’s communications network.

Brain Aging Basics

Brain aging is a natural occurrence in older adults, and roughly mirrors the aging process that affects other parts of the body. However, according to the results of a study published in 2010 in the journal NeuroImage, the initial signs of aging appear in certain parts of the brain as early as one’s 20s and 30s. No species closely related to humans shows similar age-related changes in their brains; however, members of these species may simply reach the limit of their natural lifespan before their brains can change to any large extent. Because of this extended lifespan of humans, age-related changes in the brain become more noticeable and cause more problems over time.

Structural changes account for many of the signs and harmful symptoms associated with brain aging. Much of this change stems from the gradual loss of grey matter, the darker tissue of the brain and spinal cord that plays an essential role in the brain’s ability to operate in a coordinated manner and provide the control and command signals required to keep the body running properly. In addition, dramatic structural changes occur in the brain’s white matter, the tissue containing nerve fibers.

According to a study published in 2011 in the Proceedings of the National Academy of Sciences, humans naturally lose as much as 14 percent of the grey matter content of certain parts of the brain between the ages of 30 and 80. During that time, the brain loses as much as 24 percent of its white matter. The age-related loss of grey matter occurs at a fairly steady rate over time; however, fully three-quarters of the age-related loss of white matter occurs after a given individual reaches age 70.

The Role of Cocaine Abuse

In 2012, researchers from the University of Cambridge released the results of a study that examined the structural changes inside the brains of habitual cocaine users/abusers between the ages of 18 and 50. The study found that habitual cocaine use increases the rate of age-related loss of grey matter by almost 100 percent. Specific regions of the brain where grey matter loss is most prominent in cocaine users include the prefrontal cortex—which sits toward the front of the brain—and the paired temporal cortex, which sits on each side of the brain near the exterior region known as the temple. Together, these regions play a critical role in memory, the ability to make rational decisions, the ability to focus and pay attention, and the ability to control impulsive behavior.

Cocaine’s effects on brain size are cumulative over time, and each year of continued use adds to the deficit in grey matter. This means that chronic cocaine use may have an especially devastating brain-aging effect on younger people who continue to use the drug throughout their lives. Although no one knows for sure, a cumulative loss of grey matter may explain middle-aged cocaine users’ tendency to develop problems with the basic mental function not usually seen until much later in life. These problems typically involve impairments in parts of the brain that researchers now know shrink relatively rapidly in cocaine users.