Symptoms include intense cravings for nicotine, anger or irritability, anxiety, depression, impatience, trouble sleeping, restlessness, hunger or weight gain, and difficulty concentrating.[1][2][3] Withdrawal symptoms make it harder to quit nicotine products and most methods for quitting smoking involve reducing nicotine withdrawal.[1] Quit smoking programs can make it easier to quit.[1] Nicotine withdrawal is recognized in both the American Psychiatric Association Diagnostic and Statistical Manual and the WHO International Classification of Diseases.