I don’t know if people choose not to realise that drug abusers and alcoholics embrace social vices because of circumstances. Alcoholism and drug abuse are fuelled by circumstances and the influence around these people. 

In most cases, many people try drugs or alcohol out of curiosity, or perhaps to have a good time. But a great number of people that indulge in drug use or consumption of alcohol do so because of peer pressure. When friends are doing it, another will be tempted to ‘blend in’ too.  Some people will do anything to please their friends. If you are not extremely principled you may end up drinking; there have been cases or circumstances where girls use drugs just to please a guy they are dating and in doing so, end up totally hooked. It starts with casual behaviour and before you know it, it has blossomed into a real problem. Therefore, drug abuse and alcoholism are not choices, but vices that prey on the weak. Circumstances such as trauma, stress, anxiety, or depression have been attributed by psychologists in leading to drug abuse or alcoholism. I have personally witnessed some of my friends drinking alcohol just because they are heartbroken. In most cases, drugs or alcohol have been as used a way out of a problem.   After drinking alcohol or using drugs the abuser may feel a temporary confidence or happiness for even the shortest time possible. But when it wears out, the unhappiness or anxiety returns and takes an even stronger toll on an individual, forcing them to consume more and eventually turning into addiction. According to an article by helpguide.org "Drug Abuse & Addiction,” learning about the nature of drug abuse and addiction, how it develops, what it looks like, and why it can have such a powerful hold will give you a better understanding of the problem and how best to deal with it. The article further states that as with many other conditions and diseases, vulnerability to addiction differs from person to person. Your genes, mental health, family and social environment all play a role in addiction. Risk factors that increase your vulnerability include abuse, neglect, or other traumatic experiences in childhood, mental disorders such as depression and anxiety or methods of administration either through smoking or injecting a drug may increase its addictive potential.