Depressants Smaller doses of depressants cause effects similar to alcohol, including calmness, relaxed muscles, slurred speech, poor physical coordination, and altered perception. Larger doses can cause respiratory depression, coma and death. The combination of depressants and alcohol is extremely dangerous because it multiplies the effects of both drugs. Like many other drugs, the use of depressants can become psychologically and physically addictive. Regular users also develop tolerances and require larger and larger doses.
Withdrawal symptoms range from restlessness, insomnia and anxiety to convulsions and death.
Hallucinogens These drugs, the most common of which are PCP and LSD, have extremely unpredictable effects on users. They have been known to cause violent mood swings, anxiety attacks, confusion, disorientation, panic, severe paranoia, and hallucinations. Narcotics Use of narcotics such as heroin initially produce a feeling of euphoria, followed by drowsiness, nausea and sometimes vomiting. An overdose may produce slow and shallow breathing, clammy skin, convulsions, coma and even death. Tolerance to heroin and other narcotics develops rapidly.