Risk factors

Anyone who smokes or uses other forms of tobacco is at risk of becoming dependent. Factors that influence who will use tobacco include:

• Age. Most people begin smoking during childhood or the teen years. The younger you are when you begin smoking, the greater the chance that you'll become addicted.
• Genetics. The likelihood that you will start smoking and keep smoking may be partly inherited. Genetic factors may influence how receptors on the surface of your brain's nerve cells respond to high doses of nicotine delivered by cigarettes.
• Parents and peers. Children who grow up with parents who smoke are more likely to become smokers. Children with friends who smoke are also more likely to try it.
• Depression or other mental illness. Many studies show an association between depression and smoking. People who have depression, schizophrenia, post-traumatic stress disorder or other forms of mental illness are more likely to be smokers.
• Substance use. People who abuse alcohol and illegal drugs are more likely to be smokers.