Long-Term Effects of Methamphetamine Abuse

The long-time effects of methamphetamine abuse can be more severe that those of some other illicit drugs and some of those effects can be irreversible.

One of the negative consequences of long-time meth abuse is developing an addiction to the drug. Methamphetamine addicts will continue compulsive drug seeking and drug use in spite of negative consequences. This is due to changes in the brain that changes the user's reward system.

As with other drug addictions, meth addicts develop a tolerance to the drug, requiring higher dosages to get the same effect, and they experience withdrawal symptoms if they try to quit.

National Institute on Drug Abuse research has shown that long-term meth abusers' brains are changed to the point that they may find it difficult to experience any pleasure other than that provided by the drug. This provokes even further drug abuse.

Chronic methamphetamine abusers can also experience other symptoms, including:

• Anxiety
• Confusion
• Insomnia
• Mood disturbances
• Violent behavior

Meth abuse can also produce a variety of psychotic features that can include paranoia, visual and auditory hallucinations, and delusions. Some chronic methamphetamine abusers report the sensation of insects creeping under the skin.

Unfortunately, some of these psychotic symptoms can persist for months or years after the abuser quits using meth. Reoccurrence of these symptoms can be triggered by stress long after the person has stopped using.

NIDA-sponsored neuroimaging studies have found that meth use alters the dopamine system associated with reduced motor speed and impaired verbal learning.

Methamphetamine abuse can also negatively affect non-neural brain cells called microglia, which support the brain by removing damaged neurons and defending the brain against infectious agents. But, too much microglial activity can damage healthy neurons in the brain.

Imaging studies have detected double the levels of microglial cells in the brains of former methamphetamine abusers, compared with people who never used meth.

Some studies have found that some of the brain damage caused by chronic methamphetamine abuse is partially reversible. Motor and verbal memory have shown to improve after extended abstinence from methamphetamine (14 months, but not six months).

However, other brain functions damaged by meth abuse did not recover even after 14 months, one study found.

There are other physical effects that methamphetamine users can experience including weight loss, skin sores, and severe tooth decay and tooth loss, a condition known as meth mouth.