Long-term use of methamphetamine

Long-term use of crystal meth may result in addiction. Crystal meth abuse can also cause violent behavior, anxiety, and insomnia, as well as psychotic behavior such as paranoia, hallucinations, mood swings, and delusions. The crystal meth user can also develop a tolerance to the drug, which requires the user to take increasing amounts to induce the desired effects. Chronic users of crystal meth are also characterized as having poor hygiene, a gaunt or pale complexion, and, at times, sores on their bodies from scratching at "crank bugs", which is a common delusion that bugs are crawling under their skin. Additionally, long-term use of crystal meth can cause damage to the dopamine-producing cells of the brain.