Chronic Meth Use Damages Brain Structures, Impairs Mental Flexibility
Methamphetamine, the chemically related substance amphetamine, cocaine and a range of other stimulants all achieve their basic effects by increasing the brain’s output of pleasure-producing chemicals and speeding up the rate of chemical and electrical communication in the brain and spinal cord. However, unlike other stimulants of abuse, methamphetamine has a dual impact inside the brain that results in especially profound forms of these effects. In habitual users of the drug, short-term changes in brain function can lead to the long-term changes necessary to produce physical dependence and addiction. Figures from a federally sponsored undertaking called the National Survey on Drug Use and Health indicate that roughly 0.2 percent of all American teens and adults abuse methamphetamine in a given month (this seemingly very low rate equates to 444,000 individuals). Approximately 0.4 percent of all teens and adults abuse the drug at least once in a 365-day time frame.
Known Associated Problems
In addition to the strong chance of developing a methamphetamine addiction (known technically as a form of stimulant use disorder), chronic users of the drug are susceptible to a number of other serious health problems. These problems include such things as unusual episodes of violence or aggression, an unusual tendency toward “down” or anxious states of mind, an inability to properly store or recall memories, an inability to think clearly or properly coordinate muscle movements, extensive deterioration of the teeth and gums (sometimes known as “meth mouth”), difficulty maintaining a healthy weight and the onset of hallucinations, delusions and other symptoms of the severely dysfunctional mental state called psychosis. Chronic methamphetamine users also run the risk of seriously altering the way in which the brain works, as well as the underlying physical structures that support normal brain function.
Structural Brain Damage
In March 2014, the National Institute on Drug Abuse reported the results of a study, published in late 2013 in the journal Psychopharmacology, by researchers from UCLA. These researchers used laboratory experiments with vervet monkeys to document the changes that chronic methamphetamine use triggers in the brain’s structures. One of the underlying goals of the experiments was to determine how much of the structural change in chronic meth users appears before a recurring pattern of drug use sets in and how much of the change appears after the onset of a recurring pattern of drug use. Vervet monkeys were used because of the close structural resemblance between their brains and the brains of humans. The specific brain areas under consideration play a prominent role in helping both humans and monkeys control habitual patterns of behavior.
The researchers gave increasing doses of methamphetamine to seven vervet monkeys for 31 days. For the sake of comparison, they subjected a second group of seven monkeys to harmless saline injections for the same amount of time. At the outset of the experiment, both groups of monkeys had an equal ability to control their habitual behaviors. However, after three weeks of meth exposure, the monkeys in the first group substantially lost this ability and had difficulty shifting their behaviors out of habitual “ruts.” Brain scans called MRI (magnetic resonance imaging) scans revealed that the methamphetamine-exposed monkeys had significant structural changes in the brain areas responsible for establishing behavioral control.
The authors of the study published in Psychopharmacology believe that structural change in the part of the brain tasked with controlling habitual behavior helps explain why addiction specialists find it so difficult to treat methamphetamine addiction, as well as partially explaining the relatively high chances that any given recovering addict will lapse at least temporarily back into meth use. They believe that treatment options developed in the future may help offset the chemical and structural problems in the brains of affected individuals. Potential examples of these options include medications that change the chemical balance in the brain and physical and mental exercises that could help restore structural functionality to the damaged brain areas.