Although depression is classified as a mental condition, its causes, like its symptoms, are not restricted to the mind. Depression remains a serious condition with varying causes that can prove mentally, emotionally and physically disabling. Fortunately, depression is a treatable condition. However, successful treatment is predicated on the identification of its cause. Therapy alone may not prove sufficient for patients with a family history of depression.
Risk
According to Drs. Douglas F. Levinson and Walter E. Nichols of the Stanford School of Medicine, genetics prove a major factor in the development of depression. Specifically, individuals with a parent or sibling who suffers from major depression have a 20 to 30% chance of developing depression whereas someone with no family history of depression has a 10% chance.
Depression Gene
No specific gene has been identified as the cause of depression. From a biological standpoint, depression results because of a chemical imbalance in the brain. As such, medications can help to regulate this imbalance. The lack of serotonin, a neurotransmitter associated with mood, is compensated for by anti-depressant medications known as Selective Serotonin Reuptake Inhibitors (SSRIs). Common SSRIs include Prozac, Paxil and Zoloft.
Brain Scans
According to the National Institute of Mental Health (NIMH), the parts of the brain responsible for controlling mood, processing thoughts, regulating sleep and maintaining appetite prove noticeably different in individuals with or without depression. The abnormal development and functioning of these parts of the brain may result from heredity.
Research Studies
Research studies involving the development of twins separated at birth support the argument that some individuals prove genetically predisposed to depression. For example, Drs. Levinson and Nicols of Stanford indicate that identical twins are at a 40 to 50% risk of developing depression if their sibling has the disorder. They also state that adopted children present an increased risk to develop depression if they have a biological parent diagnosed with depression.
Other Factors
Genetics are not the sole indicator of a individual's susceptibility to depression. Other factors, such as environmental circumstances, also impact the development and course of depressive episodes. According to a study by KS Kendler et.al., published by The American Journal of Psychiatry in 1995, individuals with a genetic predisposition to depression may present more of a risk for major depression due to an increased sensitivity to stress.
References
- Stanford School of Medicine: Major Depression and Genetics
- National Institute of Mental Health (NIMH) - Depression
- "The American Journal of Psychiatry"; Stressful life events, genetic liability, and onset of an episode of major depression in women;KS Kendler, RC Kessler, EE Walters, C MacLean, MC Neale, AC Heath and LJ Eaves; 1995
