Symptoms:

Some of the symptoms and behaviors of drug dependence include:

• Confusion
• Continuing to use drugs even when health, work, or family are being harmed
• Episodes of violence
• Hostility when confronted about drug dependence
• Lack of control over drug abuse - being unable to stop or reduce alcohol intake
• Making excuses to use drugs
• Missing work or school, or a decrease in performance
• Need for daily or regular drug use to function
• Neglecting to eat
• Not caring for physical appearance
• No longer taking part in activities because of drug abuse
• Secretive behavior to hide drug use
• Using drugs even when alone

See: Drug abuse for more information about symptoms that may be present when using these drugs.

For information about symptoms of withdrawal, see also:

• Cocaine withdrawal
• Opiate withdrawal

Signs and tests:

Drug tests (toxicology screens) on blood and urine samples can show many chemicals and drugs in the body. How sensitive the test is depends upon the drug itself, when the drug was taken, and the testing laboratory. Blood tests are more likely to find a drug than urine tests. However, urine drug screens are done more often.

Opiates and narcotics are usually in the urine 12 to 36 hours after the last use, depending on the amount used and how often the drug was used.

CNS stimulants such as cocaine can be found in urine for 1 to 12 days, again depending on how often the drug was used.

CNS depressants such as Valium and Xanax are found up to 7 days after the last day of use, mostly depending on the substance used and how quickly the body removes it (its half-life).

Most hallucinogens also can be found in the urine up to 7 days after the last use. However, evidence of marijuana can be found for up to 28 days after its last use in regular users.