Methamphetamine addicts can have pretty serious neurological problems, like motor skills and verbal memory. Researchers at the UCLA School of Medicine wanted to map out the shape of a meth addict's brain and find connections between these problems and brain shape.

What the researchers wanted to know: What does the brain of a methamphetamine abuser look like? Does the structure of a methamphetamine abuser's brain reflect learning disability or memory loss?

What they did: Researchers recruited 43 HIV negative people for the study–21 control people and 22 methamphetamine abusers. All the participants underwent physical examinations to make sure that they were relatively healthy (no diseases, no psychoactive drugs, etc.). The methamphetamine abusers had been using the drug for an average of 10.5 years, and six of them also smoked more than one joint a day or had a history of dependence on pot. Researchers, therefore, studied the results of the tests with and without these six participants. Both the methamphetamine users and the control group took surveys about their drug use. The researchers tested both groups for their abilities to remember pictures and words, analyzed the participants for depression, and performed MRI scans of their brains. An image analyst outside the study (who did not know what he was looking for) mapped the images of the participants' brains.

What they found: The methamphetamine abusers' brains looked pretty different. The right hemispheres had serious deficits of gray matter, the kind of brain tissue that contains nerve cells. This part of the brain controls emotions and craving, and when meth users lose cells in this area, they end up needing more meth to feel satisfied. They also lose some memory capacity. The ventricles in the right side also became bigger, a typical feature of certain neurological disorders. The average meth user had a smaller hippocampus and increased white matter in the brain. White matter is the part of the brain that contains nerve fibers, and it increases because brain damage causes the tissue to swell. When users stop taking meth, the swelling seems to go away. The smaller the hippocampus size, the worse the participants tended to do in remembering words. The transformations of the brain size of the methamphetamine abusers were similar to or worse than typical changes in the brains of people with dementia or schizophrenia. The methamphetamine abusers were also more likely to describe themselves as depressed in the surveys.

What this means to you: Methamphetamines cause serious damage in your brain, so maybe you shouldn't do them. Not to mention the jail time.

Caveats: Researchers still aren't sure how the changes in the brains of methamphetamine abusers occur or if they can be fixed. There were many more smokers in the methamphetamine group than in the control group, so maybe tobacco is playing some role is brain damage.

Find out more: Facts on methamphetamines from the National Institute of Drug Abuse.

Read the article: Thompson, Paul M., et al. "Structural Abnormalities in the Brains of Human Subjects Who Use Methamphetamine." The Journal of Neuroscience. June 30, 2004. Vol. 24, No. 26, pp. 6028-6036.