Gender:
Gender can play a role. Men are more likely to develop alcoholism (this is not to say, however, that there are not alcoholic women, there are). This is hardly surprising. In many cultures men drink more than women, much more. It is a part of their daily lives. After work, while socializing, to relax, to celebrate, to forget. The more a person drinks the more likely he is to develop alcoholism.

Changes in the Brain:
Over time alcohol will alter brain chemistry. Most importantly, when you drink your brain produces dopamine. Dopamine makes you feel good (from the same family of chemicals as morphine, which makes you feel really good but is highly addictive). Unfortunately your body builds up a tolerance to dopamine so you need more and more alcohol to get that feeling of pleasure. The more you drink the more chance there is of developing alcohol dependence.

Genetics:
Research over the past few years has pointed to the fact that people are more likely to develop alcoholism whose parents have or have had a drinking problem. Studies carried out all over the world now support that alcoholism and genetics go hand in hand. Hereditary alcoholism is a real danger among those with an alcoholic family member.

Social:
Alcohol is everywhere. Our society drips with the stuff. It is legal and socially acceptable and, sometimes, socially required (try refusing a drink in some situations and people will think your subnormal). The pressure to drink can be huge. Being around heavy drinkers as a child can also increase the chances of developing dependence.

Personality type:
People with certain personality traits are said to be more likely to drink alcoholically. There is such a thing as an alcoholic personality.An alcoholic personality displays such traits as perfectionism, an inability to cope with frustration , emotional immaturity and competitive in nature. Alcohol dependents are more likely to have problems communicating, feel socially inferior, a guilt complex, low self-esteem and depressive tendencies.

Environmental:
As genes play a role in alcoholism so does your environment. Growing up in a society/family/neighborhood where alcohol is everywhere is, of course, going to make it more likely that you will develop alcoholism. For example, a son with a drinking father is more likely to be a drinker regardless of genes, he becomes what he sees. He 'learns' to drink. Living with an alcoholic is a high risk factor.