Neurotoxicity refers to the damage to neurons in the brain that may or may not be entirely reversible. Meth interacts with dopamine and serotonin nerve terminals in the brain, which can interfere with the normal release of these neurotransmitters. This can lead to neurotoxicity, which is incredibly dangerous.
How Meth Works
Methamphetamine, or meth, is a powerful stimulant drug, abused by more than 650,000 Americans at the time of the 2016 National Survey on Drug Use and Health (NSDUH).
When used recreationally, meth causes levels of dopamine and serotonin to spike. It interacts with the transmission, production, and reabsorption of these important neurotransmitters. With repeated meth use and disruption of the dopamine and serotonin nerve terminals in the brain, the cells can be damaged.
Meth can have toxic effects on the nerve terminals, which can lead to a depletion of dopamine and serotonin in the brain. Dopamine and serotonin help to regulate emotions and are involved in memory and learning functions. They also aid in movement and sleep abilities.
Neurotoxicity related to meth use can cause thinking and memory problems, sleep disruptions, significant mood swings, uncharacteristic and unpredictable behaviors, and a weakened immune system. It even leads to the onset of a movement and nerve disorder such as Parkinson’s disease.
Meth neurotoxicity can lead to lasting cognitive, emotional, and physical problems.
Serotonin and Dopamine
Meth is abused for its stimulant, hallucinogenic, euphoric, and empathogenic properties, the journal Life Sciences publishes.
Meth causes a rush of euphoria, or a burst of pleasure, and a meth high can be intense. This is created by a surge of dopamine and serotonin in the brain that is stimulated by meth.
Dopamine is a neurotransmitter the brain uses to regulate learning, movement, attention, and emotions. Serotonin is another of the brain’s neurotransmitters involved in learning and memory functions as well as mood regulation. These are two of the brain’s chemical messengers involved in the reward pathway, and high levels of dopamine and serotonin can make a person feel happy.
Meth is also a central nervous system stimulant, which means it speeds up one’s heart rate and blood pressure while raising body temperature and increasing wakefulness, alertness, and energy levels. Meth intoxication can make a person feel excited, euphoric, and more energetic.
The meth high can wear off rather quickly, as dopamine and serotonin levels drop. The comedown can make a person feel fatigued, depressed, anxious, and mentally cloudy.
The desire to use meth again to relieve these negative feelings and increase pleasure can be significant. It is part of what makes meth so addictive.
Meth and Brain Damage
Regular and repeated meth use can interfere with how the brain makes, moves around, and reabsorbs dopamine and serotonin. This can have neurotoxic effects on the nerve terminals for these chemical messengers, leading to significantly low levels of the neurotransmitters.
The journal Frontiers in Psychology reports that meth neurotoxicity is caused by excitotoxicity, oxidative stress, and neuroinflammation.
Excitotoxicity is caused by the way meth interacts with glutamate levels in the brain. As a stimulant drug, meth increases levels of glutamate (an excitatory neurotransmitter). Chronically high levels of glutamate in the brain can have neurotoxic effects.
Oxidative stress has to do with mitochondrial dysfunction and the oxidation of dopamine in the brain, which also has toxic effects and leads to the death of neurons.
Neuroinflammation is a response to damage to the central nervous system. It is related to the neurotoxic impact of meth use.
Effects of Meth Neurotoxicity
Meth use can create an intense and euphoric high, but high doses of the drug can also cause psychosis, hallucinations, agitation, paranoia, delusions, and compulsive behaviors like skin picking, tremors and muscle twitches, aggression, and violent behaviors.
Chronic heavy meth use can cause damage to the structure and function of the brain, bringing neurotoxic effects.
In general, it takes repeated meth use in large amounts over a period to have a toxic impact, but one high dose can cause psychosis and negative effects of meth.
The National Institute on Drug Abuse (NIDA) warns that the following are side effects of brain damage related to meth use:
- Reduced coordination
- Impaired verbal learning
- Trouble regulating emotions
- Sleep disturbances
The onset of the nerve and movement disorder Parkinson’s disease can also be a side effect of meth neurotoxicity, as can symptoms of Alzheimer’s disease and a weakened immune system, the Center for Substance Abuse Research (CESAR) publishes.
Additional signs and effects of meth neurotoxicity can include:
- Difficulties thinking clearly
- Psychosis similar to schizophrenia
- Impulse control issues
- Poor concentration
- Impaired decision-making abilities
- Working memory impairment
- Difficulties with fine motor skills
- Suicidal or homicidal thoughts
The journal Behavioural Neurology publishes that meth neurotoxicity can have long-ranging consequences, including medical, legal, and social ramifications related to increased risk-taking behaviors, cognitive, and emotional deficits.
Is it Reversible?
NIDA publishes that some of the brain damage caused by chronic, repeated, and heavy meth use may be at least partially reversible with abstinence. Some of the neurotoxic effects may not be reversible, however.
Meth neurotoxicity can be extremely dangerous, having long-lasting and potentially permanent effects on emotions, cognition, and personality. Stopping meth use is the best way to minimize neurotoxic effects.