Methamphetamine.

Methamphetamine

What is it?

Methamphetamine also knows as meth or ice is a psychostimulant drug. It enters the brain and releases dopamine and serotonin. Meth is a white, odorless, crystalline powder. It can be taken orally, snorted, smoked, or injected.

What effects does it have on the user?

Long-term methamphetamine abuse has many negative health consequences, including extreme weight loss, severe dental problems, anxiety, confusion, insomnia, mood disturbances, and violent behavior. Chronic methamphetamine abusers can also display a number of psychotic features, including paranoia, visual and auditory hallucinations, and delusions.

How does it affect society?

Methamphetamine plays a huge roll in the transfering of HIV. Many meth users reuse needles because they do not think clearly.  
Studies of methamphetamine abusers who are HIV-positive indicate that HIV causes greater neuronal injury and cognitive impairment for individuals in this group compared with HIV-positive people who do not use the drug.

How many users in the U.S?

Fortunately the number of meth users has been declining the most recent study, in 2008, showed that 314,000 people were users.