The main cause of drug addiction is the person's own individual choices and decisions. While there are many factors that can contribute to someone's decision to start using drugs, ultimately it is their own choice that leads them down the path of addiction. There are many reasons why someone might choose to start using drugs, including curiosity, peer pressure, and boredom. However, once someone starts using drugs, they quickly develop a physical and psychological dependence on the substance. This dependence leads them to continue using drugs, even when they are aware of the negative consequences. Over time, this addiction can take over their life, leading to financial, social, and personal problems. While there are many programs and treatments available to help people overcome their addiction, ultimately it is up to the individual to make the decision to seek help.