Although the brain has incredible reserve power, Dr. Schuster believes that people who have used high doses of methamphetamine will eventually lose some cognitive ability.

High doses of methamphetamine have a clear physiological effect on the brain, but its long-term effects on people’s ability to function are uncertain. With more than $1 million from the National Institutes of Health, Dr. Charles Schuster is using PET imaging and specialized neurocognitive tests to determine whether or not methamphetamine (MA) causes a deficiency in brain function.

“The loss of functional ability has been evidenced in animals, but it’s harder to pinpoint in humans,” said Dr. Schuster, professor of psychiatry and behavioral neurosciences. Levels of important brain chemicals, namely dopamine and serotonin, can be reduced by 50 percent in MA abusers, but behavioral symptoms are generally not detected until depletion reaches 70 or 80 percent. Dr. Schuster likens this puzzle to patients with Parkinson’s disease who display severe neurological impairments by the time they have lost 90 percent of the dopamine in their system. Still, at a 75 percent loss, they are completely asymptomatic. The loss of brain function can not be detected until it is too late.

“We know that there is a gradual loss of serotonin and dopamine with the normal aging process,” said Dr. Schuster. “We need to know how dramatic that normal loss may be if combined with a drastic loss of dopamine from previous experience with drug abuse. A person may have no detectable brain deficiencies until they reach a particular threshold. At the moment, however, we can’t pinpoint that threshold,” he said.

A current study, being conducted by Dr. Schuster and his research team, will assess neurological functioning in people who have used high doses of methamphetamine in the past. Patient enrollment is currently underway in conjunction with collaborators from the University of Michigan, Haight-Ashbury Free Clinic, Sinai Hospital, and the University of Cambridge. To refer patients or get more information, call (313) 993-3960 or (888) 457-3744.