Depression is a mental disorder characterized by a persistent low mood, an inability to enjoy life, and decreased energy. There is no single cause of depression, but various psychological theories have been proposed to explain its causes.
The most well-known theory of depression is the biomedical model, which asserts that a combination of genetic and environmental factors causes depression. This theory is based on the observation that some people are more likely to develop depression than others and that depression is often associated with a particular constellation of medical conditions (such as heart disease, diabetes, and obesity).
Other psychological theories of depression include the cognitive, self-fulfilling prophecy, and learned helplessness models. The cognitive model postulates that a deficit in cognitive abilities, such as willpower and self-confidence, causes depression. The self-fulfilling prophecy model suggests that people with a pessimistic outlook on life tend to experience more difficulties in life, confirming their pessimistic beliefs. Finally, the learned helplessness model suggests that people who believe they cannot control their destinies are more likely to develop depression.
Despite the many theories of depression, much is still unknown about the causes and treatment of this disorder. Theories of depression are constantly evolving, and new research is being conducted to improve our understanding of this complex mental illness.
