No specific cause for depression has been identified, but there are a number of factors believed to be involved.
• Heredity - The tendency to develop depression may be inherited; there is some evidence that this disorder may run in families. Brain chemicals called neurotransmitters allow electrical signals to move from the axon of one nerve cell to the neuron of another. A shortage of neurotransmitters impairs brain communication.
• Physiology - There may be changes or imbalances in chemicals which transmit information in the brain, called neurotransmitters. Many modern antidepressant drugs attempt to increase levels of certain neurotransmitters, like serotonin. While the causal relationship is unclear, it is known that antidepressant medications do relieve certain symptoms of depression. Seasonal affective disorder (SAD) is a type of depressive disorder that occurs in the winter when daylight hours are short. It is believed that the body's production of melatonin, which is produced at increased levels in the dark, plays a major part in the onset of SAD, and that many sufferers respond well to bright light therapy, also known as phototherapy. High levels of Omega-6 fatty acids in the brain have also been linked to depression.
• Psychological factors - Low self-esteem and self-defeating or distorted thinking are connected with depression. While it is not clear which is the cause and which is the effect, it is known that sufferers who are able to make corrections to their thinking patterns can show improved mood and self-esteem. Psychological factors include the complex development of one's personality and how one has learned to cope with external environmental factors, such as stress.
• Early experiences - Events such as the death of a parent, abandonment or rejection, neglect, chronic illness, and severe physical, psychological, or sexual abuse can also increase the likelihood of depression later in life. Post-traumatic stress disorder (PTSD) includes depression as one of its major symptoms.
• Life experiences - Job loss, financial difficulties, long periods of unemployment, the loss of a spouse or other family member, or other traumatic events may trigger depression. Long-term stress, at home, work or school, can also be involved.
• Medical conditions - Certain illnesses including hepatitis, mononucleosis, and hypothyroidism may contribute to depression, as may certain prescription drugs such as birth control pills and steroids.
• Alcohol and other drugs - Alcohol can have a negative effect on mood, and misuse or abuse of alcohol, benzodiazepine-based tranquillizers and sleeping medications, or narcotics can all play a major role in the length and severity of depression. The link between cannabis abuse (as opposed to use) and depression is also widely documented.
• Postpartum depression - About ten percent of new mothers experience some form of depression after childbirth. When it occurs, the onset is typically within three months after delivery, and it may last for several months. About two new mothers out of a thousand have depression so severe it includes hallucinations or delusions.
• Living with a depressed person - Those living with someone suffering from depression experience increased anxiety, and life disruption, which increases the possibility of their also becoming depressed.
• Social Environment Evolutionary theory - suggests that depression is a protective mechanism: if an individual is involved in a lengthy fight for dominance of a social group and is clearly losing, depression causes the individual to back down and accept the submissive role. In doing so, they are protected from unnecessary harm. In this way, depression maintains the social hierarchy.
• Other Evolutionary Theories - Another evolutionary theory is that the cognitive response that produces modern day depression evolved as a mechanism that allows people to assess whether they are in pursuit of an unreachable goal. Still others claim that depression can be linked to perfectionism. People that accept satisfactory outcomes in lieu of "the best" outcome tend to lead happier lives.
Lisa Angelettie, M.S.W., is a psychotherapist, author, and an online advice expert. She has been helping people make smarter life choices since 1998. Visit her for Advice & Counseling, or take a free Depression Screening today. Subscribe to the growing self-help ezine "Better Choices". Contact info: info@GirlShrink.com
