What causes depression? It’s a question that has no simple answer. However, there is significant evidence that causes of depression may be related to biochemical imbalances in the brain. It’s less clear whether external factors (stress or grief, for example) cause the biochemical imbalance, or if the biochemical imbalance makes a depressed patient more susceptible to such external factors.

What researchers do know is that almost one-third of all mental health patients suffer from depression symptoms. Some professionals suspect that many more suffer through bouts of depression without receiving the mental health care they need. Often, sufferers of depression rely on substance abuse instead of seeking treatment.

According to the Help Guide website, 10 percent of the male population suffer from depression symptoms at some point in their lives. Rates of depression in women are even higher — 25 percent. Teenage depression is also on the rise, a problem that’s reflected in the fact that half a million teenagers attempt suicide every year in the United States alone.

Genetic Depression Causes

Some types of depression, such as bipolar disorder and severe major depression, appear to run in families, which indicate genetic causes of depression. Studies performed by the Medical College of Virginia’s psychiatric department involving identical twins have shown that if one twin suffers from depression or bipolar disorder, the other twin has a 70 percent chance of also having the disorder.

Similar studies were done on adopted children. A child adopted into a family with mental health issues is no more likely to share those problems than any other child. However, the Stanford School of Medicine found that if a child’s biological family members suffers from depression, the child is three times more likely to also experience depression, further suggesting genetic depression causes.

Stress-Related Depression Causes

It’s also possible to experience stress-related causes of depression. Some common triggers include:

  • Chronic illness
  • Family crisis
  • Personal loss
  • Problems at home, at work or with finances.

Stress plays an important role in depression. In fact, a vital aspect of treatment of depression symptoms is stress reduction.

Biological Causes of Depression

Studies have indicated that an imbalance in the brain’s serotonin levels may be one of the causes of depression. Serotonin is one of the key mood regulators in the human brain. Too little serotonin may be what causes depression, while irregular serotonin levels contribute to bipolar disorders or manic depression. A family of pharmaceuticals called selective serotonin reuptake inhibitors (SSRIs) can help regulate the brain’s serotonin levels and bring relief to those suffering from depression symptoms.

No one is entirely certain what causes depression — that is, whether personal experience or biochemical imbalances cause depression symptoms. Both therapy and drug treatments have proven effective in combating major depression, so the answer may lie somewhere in between.


Croft, H. (2009). Causes of depression. Retrieved April 7, 2010, from the Healthy Place website: http://www.healthyplace.com/depression/main/causes-of-depression/menu-id-943/.

Depression.com Staff. (n.d.). Causes of depression. Retrieved April 7, 2010, from the Depression.com website: http://www.depression.com/causes_of_depression.html.

Eaves, L.J., Heath A.C., Kendler, K.S., Kessler, R.C. and Neale, M.C. (1993). A longitudinal twin study of personality and major depression in women. Retrieved April 8, 2010, from the PubMed website: http://www.ncbi.nlm.nih.gov/pubmed/8215811.

Holt, K. (2010). Depression — Symptoms, causes and treatment options. Retrieved April 7, 2010, from the Daily Break website: http://dailybreaknews.com/depression-symptoms-causes-and-treatment-options/6856.

Levinson, D.F. and Nichols, W.E. (n.d.). Major depression and genetics. Retrieved April 8, 2010, from the Stanford School of Medicine website: http://depressiongenetics.stanford.edu/mddandgenes.html.

Smith, M. (2009). Understanding depression: Signs, symptoms, causes and help. Retrieved April 7, 2010, from the HelpGuide website: http://helpguide.org/mental/depression_signs_types_diagnosis_treatment.htm.

 Posted on : June 26, 2014