Theory of Depression

The effects of depression on a person's everyday life can be debilitating and can grow increasingly worse with time. As of yet, the specific cause for this condition remains unknown. The physical and psychological components that accompany depression symptoms have formed the basis for a number of theories on its origin.

Identification

• Depression is classified as an affective disorder that disrupts a person's emotional state. Feelings of sadness, loss of interest in daily activities, fatigue and muscle aches and pains are all possible symptoms of this disorder. A person's emotions, thoughts and behaviors are factors that play a part in how this condition is experienced. A theory of depression will incorporate one or more of these factors to explain how this condition develops within a person's life.

Neurobiology Theory

• The neurobiological theory of depression identifies specific neural processes that contribute to the symptoms a person experiences. Chemicals in the brain called neurotransmitters are responsible for regulating the processes that take place in the body. Epinephrine, dopamine and norepinephrine are the chemicals involved in regulating emotions and thought processes. When any one of these chemicals is out of balance, depression symptoms can result. Treatment models based on this theory use antidepressant medications as a way to correct whatever chemical imbalances may be present in the brain.

Cognitive Theory

• A prominent, 20th century psychologist named Aaron T. Beck is the founder of the cognitive-behavioral branch of psychotherapy. His theory--Beck's Cognitive theory of Depression--identifies the source of depression within the thought processes of the mind. Individuals who experience symptoms like sadness, loss of self esteem and hopelessness are typically plagued with negative patterns of thinking. This theory views thought processes as the "conductors" of emotion. Treatment approaches focus on eliminating these negative thinking patterns, and replacing them with positive, constructive patterns of thinking. Once negative thought processes are gone, their resulting emotional symptoms are eliminated.

Evolutionary Theory

• Evolutionary psychology is concerned with how human behaviors relate to the survival of the species. A theory of depression, called Rank Theory, views depression disorders as a survival tactic that promotes the survival of the weaker members of a society. Individuals who accept their lower ranked status in society exhibit depression symptoms as a defensive mechanism, and as a way of coping with their status. As depression symptoms can be readily visible in the form of sadness and fatigue. These symptoms reduce the likelihood of competition or conflict with others, while at the same time work toward maintaining the social equilibrium of the species.

Malaise Theory

• The Malaise Theory of depression views the disorder as caused by a hyperactive immune system response that attacks specific chemical processes within the body. This theory defines depression as a sickness behavior caused by higher than normal levels of cytokines in the system. Cytokines are a class of immune active agents. These agents are believed to be responsible for the fatigue, and muscle aches that accompany some forms of depression. Symptoms become further aggravated by negative thought processes and emotions. Malaise theory views antidepressants as a type of analgesic, or pain-killer that reduces the number of cytokines in the system, which is why symptom relief occurs.