While the physical symptoms of withdrawal might last only a few days or a week, the psychological withdrawal, such as depression or dysphoria, can last for weeks.
For detailed information about withdrawal symptoms associated with specific drugs, please see:
Alcohol Withdrawal Symptoms
Heroin Withdrawal Symptoms
Marijuana Withdrawal Symptoms
Nicotine Withdrawal Symptoms
OxyContin Withdrawal Symptoms
Vicodin Withdrawal Symptoms
How severe are your symptoms when you try to quit?
Drug Abuse FAQ
National Institute on Drug Abuse. "Frequently Asked Questions." The Science of Drug Abuse and Addiction. Accessed February 2014