As discussed above alcohol dependence is the leading cause of missed days at work. Alcohol dependence is also associated with severe medical problems which we will discuss in more detail below. People who continue to use alcohol despite adverse effects on their health, occupational or social functioning show symptoms of alcohol dependence. Finally, some substance abuse experts define dependence solely with physiological adaptation to alcohol. In the past this has been referred to as physical dependence.
Physical dependence is shown by either tolerance or withdrawal.
Tolerance is defined as a decrease in the response to alcohol as use continues over time. Thus, it takes a progressively larger amounts of alcohol to produce the same effect. Chronic alcohol users may also experience withdrawal symptoms such as rapid heart rates or excessive sweating when they stop or decrease alcohol drinking. People who show either physical tolerance or symptoms of withdrawal are said to be physically adapted to the drug. These factors interact in complex ways to influence behavior.