The user may be more talkative, restless and excited. They may feel powerful, superior, aggressive, and even hostile. They might exhibit bizarre, repetitive behavior. Large doses can produce flushing, tremors and hallucinations. Death can be caused due to burst blood vessels, heart failure and fever.
Violence is a leading cause of amphetamine-related deaths.
Long-term effects for chronic heavy users are malnutrition and amphetamine psychosis, a mental illness. Violent tendencies can develop after long regular use. Ritalin is available in both short acting and sustained release doses. Short-acting Ritalin is available in 5 to 20 milligram tablets. In as little as 20 minutes it takes effect.