The Partnership for a Drug-Free America defines crystal meth as a form of methamphetamine that a user smokes, although some people may inject the drug instead. When a person uses crystal meth, it interferes with the neurotransmitters dopamine and serotonin, resulting in the drug high. However, as a person continues to use the drug, it can damage his brain.
Mood Changes
The University of Maryland's Center for Substance Abuse Research explains that crystal meth increases the levels of two neurotransmitters: serotonin and dopamine. Both of these neurotransmitters are linked to mood. Crystal meth mimics these neurotransmitters, causing the brain to release more dopamine and serotonin. The increased amount of these neurotransmitters causes the user to feel euphoric, and can also cause an increased alertness. As the effects of crystal meth wear off, the levels of these neurotransmitters decrease, which also change the user's mood. For example, the decrease in dopamine can result in depression, a low mood characterized by crying spells and feeling worthless or hopeless. The Partnership for a Drug-Free America adds that the changes in neurotransmitters can result in violent behaviors, or an unpredictable mood, meaning the user's mood changes from agitated to depressed.
Psychosis
While on a short-term basis, the fluctuating levels of serotonin and dopamine caused by crystal meth cause mood changes, the National Institute on Drug Abuse points out that long-term crystal meth abuse causes psychotic symptoms, which can last up to years after a person stops using the drug. The psychotic symptoms, in which the user has a break with reality, occur when dopamine levels increase. Examples of psychotic symptoms that can occur with crystal meth use include paranoia, delusions, hallucinations and repetitive motor activity such as the user her picking at the skin. With the hallucinations, users can hear or see things that do not exist. The National Institute on Drug Abuse notes that users may feel like a bug is crawling under the skin. The Partnership for a Drug-Free America adds that users may have anxiety or thoughts about death.
Addiction
The changes to the neurotransmitter levels in the brain make crystal meth an addictive drug. The University of Maryland's Center for Substance Abuse Research explains that users of crystal meth become addicted to the drug because of its intense highs and lows. For example, when a user takes crystal meth, he can feel fantastic, but when that effect wears off, he feels terrible, driving him to use the drug to regain that high. Users of crystal meth develop a tolerance of the drug, leading them to use more crystal meth to reach the same high as before. The National Institute on Drug Abuse points out that addiction is linked to physiological changes to the brain. For example, since crystal meth increases the dopamine release, the user's brain slows down its own production. As a result, the user takes even more crystal meth to compensate for his brain's decrease in natural dopamine production.
Brain Damage
The University of Maryland's Center for Substance Abuse Research notes that crystal meth damages serotonin and dopamine-producing neurons, which are cells in the brain. For example, without these dopamine-producing cells, the levels of dopamine decrease in the brain. The loss of these cells results in symptoms similar to Parkinson's disease and Alzheimer's disease, according to the Partnership for a Drug-Free America. As a result, users can have memory loss, twitching or problems moving. The changes to the brain may also result in a coma, stroke or death.
