(HealthDay News) -- Nicotine typically is as addictive as heroin, says the University of California San Francisco.
Within minutes of smoking, the brain releases chemicals that give users a rush. Smokers then get hooked on this pleasant feeling. And when people stop smoking, withdrawal side effects commonly appear.
The school mentions these signs of nicotine withdrawal:
- Anxiety or depression.
- Difficulty concentrating.
- Impaired performance.
- Increased appetite and weight gain.
- Irritability, frustration and anger.
- Restlessness and impatience.
- Sleep disturbances, such as insomnia or sleeping too much.