Usually, substance abuse begins in adolescence . Therefore, numerous studies have shown that substance abuse in adolescents is a severe and ever-growing problem , with tobacco, alcohol, and marijuana cited as the commonly used addictive primary substance that adolescents try .
Substance abuse is also a relatively common problem among Iranian adolescents. According to a report published by the Iranian Ministry of Health, the prevalence of alcohol use among Iranian adolescents (15 to 18 years old) is 15%, opium use is 3.1%, and ecstasy use is 5.6% .
The tendency to use a substance is strongly influenced by various factors such as gender, age, psychological factors affecting sensation seeking, and genetic sensitivity. In addition, interpersonal and social influences also affect adolescents' behavioral choices and health outcomes .
Based on studies, three categories of individual, family, and social factors have been identified as influential in Iranian adolescents becoming addicted . Individual factors include variables such as adolescents' attitudes toward substance abuse, self-control, social competence, and family and school attachment . Parental disputes, lack of parental support, parental divorce, and emotional deprivation are family factors that affect adolescents' addiction . Also, attitudes toward school, friends' educational status, friends' attitudes toward substances, friends' abstinence from smoking, and friends' addiction are known as social factors of addiction in Iranian adolescents .
Studies have described a significant relationship between youth reckless behavior and sensation seeking. Young people who score high on the sensation-seeking trait tend to be more prone to substance abuse and early experience in using than those who have a low score in this field . The trait of sensation seeking is related to biological and mental sensitivity to the motivational effect and enhanced effects of substances and directly correlates with the early onset of substance use and alcohol consumption . In this respect, environmental factors also act as a mediator or moderator .
Research has shown that environmental factors influence the onset of substance use . For example, neighborhoods with poor socio-economic conditions are considered high-risk environments. In these environments, parents' relationship with adolescents can be an influential factor in adolescents becoming substance users. Therefore, it is essential to consider the socio-economic environment, the social impact of peer networks, the effects of parental relationships, and the interactions between them as factors that reduce or aggravate the consequences of health behaviors .
Substance abuse has been described in several models, but a general behavior model can be helpful to understand addiction better. According to the available research, a model is considered to explain and intervene in the phenomenon of addiction, which includes a full range of concepts of addictive behavioral models. One of the models with this feature is COM_B (capability (C), opportunity (O), motivation (M), behavior (B)) . According to this model, substance abuse can be observed in situations where a person has the necessary physical and mental abilities (such as self-regulatory capacity, ability to learn from punishment, ability to formulate and adhere to personal rules), the necessary opportunities (such as environmental and social guidelines, the availability of alternative sources of reward, the cost of activities), and competing motivations (such as emotional needs, a need for belonging, the anticipation of pleasure or satisfaction, anticipation of relieving cravings, and fear of rejection).
Therefore, this study aimed to understand better the capability, motivation, and opportunities of substance abuse prevention in adolescents to design educational interventions to prevent substance abuse based on the COM-B model in a group of high school male sensation-seeking students on the outskirts of Birjand in Eastern Iran.