Methamphetamines, like many illegal drugs, act by initiating chemical changes in the brain. By affecting the brain's levels of neurotransmitters related to energy and happiness, meth creates a temporary state of euphoria. Over the long run, these same changes leave the user with a depletion of important brain chemicals after the high wears off and encourage the body to produce fewer of them, as it senses overload.
Meth's Long-Term Changes in Brain Chemistry
Many of the chemical changes meth causes in the brain are temporary; however, some imbalances created by methamphetamines can have serious long-term effects. In fact, a 2008 John Hopkins study found that memory function remains impaired in meth users, even after dependency ends. Because many of the neurological changes meth creates occur in the synapse the space between two neurons where messages are transmitted over time, its ability to send and receive impulses becomes impaired. This damage within brain cells can lead to a host of long-term problems, including attention span issues, visual problems and impaired cognitive and decision-making abilities.
As meth alters brain chemistry, it can impede the brain's ability to regulate the nervous system, as well. Many of the organ functions we take for granted each day such as heartbeat and respiration can become affected as brain chemistry shifts. Because methamphetamines affect norepinephrine chemical levels in the brain (producing adrenaline), arrhythmia and tachycardia can also occur as fight-or-flight responses become needlessly triggered into a crisis state, heightening the body's risk for heart disease and brain injuries.
Unfortunately, some long-term changes that meth induces can create prolonged psychological issues. As dependency takes hold, meth users can experience severe mood changes that linger even after sobriety is reached. Meth dependent individuals can experience long-term anxiety, clinical depression, and even suicidal ideation. Some meth users even suffer paranoid thought and accompanying hallucinations for up to a year after recovery from addiction. Personality changes can occur, as well, leaving some individuals with full-blown personality disorders or even schizophrenic psychosis, long after use stops.