There are dozens of reasons people choose to use drugs, and even more reasons that drug use - or any substance use - may lead to substance abuse and eventually dependency. Some people are biologically predisposed to substance abuse and dependency, both of which are diagnosable and treatable disorders according to the DSM-IV. Despite a biological tendency, many people avoid substance use as a personal choice or out of necessity. The reasons people may turn to substance use include variations in environment, social support and socioeconomic status that can make drugs or alcohol seem like an easy coping mechanism. Other reasons include cognitive variations, such as an impulsive personality that leads to riskier decision-making, or coexisting conditions that have a positive correlation with substance use. Understanding the reasons that people use substances makes it possible to identify dangerous situations and avoid them. A Biopsychosocial Perspective In terms of the biopsychosocial model, people are susceptible to substance abuse and dependency because of contributing biological, psychological and social factors. The biological component refers to the specific brain structures that surround the way drug use affects the body, as well as the processes leading to physical addiction. The psychological component describes how cognitive and mental processes can lead a person to substance use, whether as a coping mechanism in response to stress or because of poor cost-benefit analysis, where a person perceives the benefits of substance use as more significant than the potential costs involved. Finally, the social component refers to environmental pressures that can lead to abuse and dependence, which include family life, social support, socioeconomic status and other factors. The Biology of Substance Addiction Substance addiction has a foundation built on neurobiological functions and structures, and understanding the underlying process can make it easier to recognize and avoid problematic use. Substance use directly affects neurotransmission by blocking or activating receptors to mimic the effect of specific neurotransmitters, which varies depending on the specific drug, but usually produces a short-lived positive feeling that activates the reward centers of the brain in the amygdala, basal forebrain, and other areas that process emotion and motivation. In part, this triggers cravings, where the body feels that it needs more of the substance - one of the diagnostic criteria for substance dependence. While this explains the physical short-term reward of substance use and the long-term process of dependency and addiction, many external factors contribute to whether an individual actually chooses to use substances. Avoiding biological addiction can be difficult for people who have a genetic predisposition, but identifying addictive disorders in close family members makes a strong case for avoiding substance use that may lead to the same addictive disorder. Psychological Influences on Addictive Behavior Numerous psychological factors can influence whether a person chooses to use substances, or whether this use leads to abuse and dependence. People with neurotic, addictive or risk-seeking personalities may be more likely to use substances. Alternatively, poor coping skills or negative thought may lead to substance use and abuse as a coping mechanism in response to stress or emotional turmoil. Some psychological disorders, such as major depressive disorder or bipolar disorder, are positively correlated with substance use. People who live with these disorders should work with their mental health caregiver to find effective coping strategies instead of turning to substance use. Genetic Tendencies and Social Pressures Overlap Although not everyone has a genetic tendency toward substance addiction, those who do may have a harder time than most avoiding the social pressure to indulge. A 2010 study showed that women who are genetically predisposed toward substance addiction are more likely to seek out social support from people who are substance users. Social environment is a substantial factor that contributes to whether an individual chooses to use substances. A biological tendency toward addiction makes it more dangerous for any person to surround him or herself with people who use substances socially, as recreational use carries a heightened risk of addiction or substance abuse. According to the DSM-IV, individuals are diagnosable with substance abuse if their use falls into a maladaptive pattern. This includes failing to fulfill obligations and commitments, using substances in hazardous conditions, and substance use without regard for social, interpersonal or legal problems that result. Having a natural tendency to choose social relationships that facilitate substance use, as described in the 2010 study, can make it easier to fall into abuse and then addiction. Instead, a clean and positive social support system can help a susceptible person avoid situations that might lead to maladaptive substance use. If a positive social support system is unavailable, because of either a negative family environment or a lack of close social connections that are not substance users, seeking out a support group or therapy can provide alternative support.