Substance abuse usually begins as a social habit and then increases until the user feels he cannot live without the drug and will do anything to get it. Substance abuse affects the people around the addict. Family and friends can watch for signs of a drug addiction to determine if an individual needs help. Symptoms of drug addiction vary by the drug. Note, however, that not everyone who displays some of these symptoms is a drug addict. Watch for signs of an addiction to prescription drugs. Signs of this addiction include sleeping at inappropriate moments, droopy eyes, listlessness and drunken mannerisms, such as slurred speech and stumbling while walking or standing. Look for symptoms of cocaine addiction. Signs include unusually large pupils and glassy eyes, weak and broken teeth, needle marks on the arms that are usually covered by long sleeves even in hot water, raw nose from sniffing the drug and weight loss. Other signs include sleeplessness for an extended duration followed by periods of extended sleep, picking at body parts, irritable and aggressive behavior, sudden weight changes, no interest in food, licking lips constantly and rambling conversations. Identify an addiction to opiates. Similar to a cocaine addiction, symptoms include needle marks on the arms, pale skin, constant sweating and thirst, pinpointed pupils, constant scratching and sleeping at inappropriate times. Find out if the individual is using methamphetamines. During the "rush" of taking the drug, the individual has an elevated sense of well being, an increase in energy and a decrease in appetite. This rush lasts for six to eight hours. When it ends, the individual appears to be highly agitated, often becoming violent, performs the same task repeatedly, appears to be depressed and unfocused, is sexually promiscuous, is awake for days and maintains a rambling conversation. Examine the individual for signs of a marijuana addiction. Bloodshot eyes, dry lips, blank stares and a smell of burnt grass are common signs of this addiction. Other signs are laughing suddenly without cause, constant hunger, lack of emotion and a euphoric stupor.