<P> Smoking cessation (also known as quitting smoking or simply quitting) is the process of discontinuing tobacco smoking . Tobacco smoke contains nicotine, which is addictive . Nicotine withdrawal makes the process of quitting often very prolonged and difficult . </P> <P> Seventy percent of smokers would like to quit smoking, and 50 percent report attempting to quit within the past year . Smoking is the leading preventable cause of death worldwide . Tobacco cessation significantly reduces the risk of dying from tobacco - related diseases such as coronary heart disease, chronic obstructive pulmonary disease (COPD), and lung cancer . Due to its link to many chronic diseases, cigarette smoking has been restricted in many public areas . </P> <P> Many different strategies can be used for smoking cessation, including quitting without assistance ("cold turkey" or cut down then quit), behavioral counseling, and medications such as bupropion, cytisine, nicotine replacement therapy, or varenicline . Most smokers who try to quit do so without assistance, though only 3% to 6% of quit attempts without assistance are successful . Behavioral counseling and Medications each increase the rate of successfully quitting smoking, and a combination of behavioral counseling with a medication such as bupropion is more effective than either intervention alone . </P> <P> Since nicotine is addictive, quitting smoking leads to symptoms of nicotine withdrawal such as nicotine cravings, anxiety, irritability, depression, and weight gain . Professional smoking cessation support methods generally attempt to address nicotine withdrawal symptoms to help the client break free of nicotine addiction . </P>

Name two types of medications and/or services that have been shown to help smokers quit successfully