Several explanations (or “models”) have been presented to explain addiction. The moral model states that addictions are the result of human weakness, and are defects of character. Those who advance this model do not accept that there is any biological basis for addiction. They often have scant sympathy for people with serious addictions, believing either that a person with greater moral strength could have the force of will to break an addiction, or that the addict demonstrated a great moral failure in the first place by starting the addiction.
The moral model is widely applied to dependency on illegal substances, perhaps purely for social or political reasons, but is no longer widely considered to have any therapeutic value. Elements of the moral model, especially a focus on individual choices, have found enduring roles in other approaches to the treatment of dependencies. The disease model holds that addiction is an illness, and comes about as a result of the impairment of healthy neurochemical or behavioral processes.
While there is some dispute among clinicians as to the reliability of this model, it is widely employed in therapeutic settings. Most treatment approaches involve recognition that dependencies are behavioral dysfunctions, and thus involve some element of physical or mental disease. The genetic model posits a genetic predisposition to certain behaviors. It is frequently noted that certain addictions “run in the family,” and while researchers continue to explore the extent of genetic influence, there is strong evidence that genetic predisposition is often a factor in dependency.
Researchers have had difficulty assessing differences, however, between social causes of dependency learned in family settings and genetic factors related to heredity The cultural model recognizes that the influence of culture is a strong determinant of whether or not individuals fall prey to certain addictions. For example, alcoholism is rare among Saudi Arabians, where obtaining alcohol is difficult and using alcohol is prohibited. In North America, on the other hand, the incidence of gambling addictions soared in the last two decades of the 20th century, mirroring the growth of the gaming industry.
Half of all patients diagnosed as alcoholic are born into families where alcohol is used heavily, suggesting that familiar influence, genetic factors, or more likely both, play a role in the development of addiction. The blended model attempts to consider elements of all other models in developing a therapeutic approach to dependency. It holds that the mechanism of dependency is different for different individuals, and that each case must be considered on its own merits.
Although the term addiction is sometimes often used loosely rather than as a medical classification, there are some physiological conditions related to everyday behaviors that are also related to the more commonly recognized mechanisms associated with addiction. Pleasurable activities, like sexual activity, cause the release of endorphins, and this endorphin-rush can conceivably become ‘addictive’. Evolutionary biologists have suggested this process of attentuating pleasure pathways is part of the brain’s natural system for ensuring that humans develop abiding interests.
Since human societies depend on enduring attachments, many theorists suggest such addictions are not necessarily a problem. Other views, such as the those summarized in Buddhist concept of tanha, suggest trivial attachments are at the root of much human suffering. In general terms, endorphins stimulate activity of the neurotransmitter dopamine. Increased dopamine activity is often met by an increase in the number of receptors sensitive to dopamine. This process is called upregulation.
The increased number of receptors tends to result in reduced electrical activity along post-synaptic nerve pathways, unless some behavior or substance causes a continued high level of dopaminergic stimulation. The absence of a pleasurable sensation in conditions that were formally sufficient can cause a mild feeling of let-down after neurons have been upregulated. The increased requirement for dopamine to maintain electrical activity is the basis of both tolerance and withdrawal associated with addiction. In fact, some studies have indicated that pornography can have the same effect on the brain as drugs.