Short-term usage effects: Methamphetamine can increase wakefulness, attention and physical activity and decrease appetite and fatigue. A brief, intense sensation, or feelings of euphoria. Other effects include increased rate of respiration and hyperthermia. Long-term usage effects: Long-term usage of methamphetamine may result in dependence and addiction psychosis [which includes symptoms of paranoia, hallucinations, mood disturbances, reptitive motor activity]. Weight loss, and more seriously, stroke is possible. Chronic methamphetamine abusers exhibit symptoms that can include violent behavior, anxiety, confusion, and insomnia. With chronic use, tolerance for methamphetamine can also develop. In an effort to intensify the desired effects, users may take higher doses of the drug, take it more frequently, or change their method of drug intake. In some cases, abusers forego food and sleep while indulging in a form of binging known as a "run," injecting as much as a gram of the drug every 2 to 3 hours over several days until the user runs out of the drug or is too disorganized to continue. Chronic abuse can lead to psychotic behavior, characterized by intense paranoia, visual and auditory hallucinations, and out-of-control rages that can be coupled with extremely violent behavior. (Retrieved from http://parentingteens.about.com/cs/meth/l/blmeth4.htm)

all, the individual doesnt matter it still eats everyone up. it was explained to me that its like a drop of water on a sugar cube. thats what it does to everyone who uses.