One of the most common illnesses people suffer nowadays is depression. Depression is a common mental disorder, characterized by sadness, loss of interest or pleasure, feelings of guilt or low self-worth, disturbed sleep or appetite, feelings of tiredness and poor concentration. (WHO)

According to the definition by WHO, it seems to be a mental disorder but the latest researches made by an international team of researchers, led by the University of Granada (UGR) has scientifically proven for the first time that depression is more than a mental disorder—it causes important alterations of the oxidative stress, so it should be considered a systemic disease, since it affects the whole organism.

The results of this work, published in the renowned Journal of Clinical Psychiatry magazine, could explain the significant association that depression has with cardiovascular diseases and cancer, and why people suffering from depression die younger. At the same time, this research may help finding new therapeutic targets for the prevention and treatment of depression.

The lead author of this work is Sara Jiménez Fernández, Ph.D. student at the UGR and psychiatrist at the Child and Adolescent Mental Health Unit at Jaén Medical Center (Jaén, Spain).

This research is the first detailed work of its kind about what happens in the bodies of people suffering from depression. It consists of a meta- analysis of 29 previous studies involving 3961 people, which studies the imbalance between the individual increase of various  oxidative stress parameters (especially malondialdehyde) and the decrease in antioxidant substances such as uric acid, zinc, and the superoxide dismutase enzyme.

figura 2 Figure 2. This figure shows the other effects of depression on the whole body, which are:

  • Overwhelming sadness
  • Emptiness or hopelessness
  • Cognitive changes
  • Preoccupation with death
  • Clinginess
  • Aches and pains
  • Weight problems
  • Poor appetite
  • Constricted blood vessels
  • Heart attack outcome
  • Weakened Immune System

Malondialdehyde (MDA) is one of the final products of polyunsaturated fatty acids peroxidation in the cells. An increase in free radicals causes overproduction of MDA. It is used as a biomarker to measure the oxidative deterioration of the cell membrane.

But what is oxidative stress?

We need oxygen to live and breathe, but oxygen can also have a detrimental effect on our bodies. Oxygen is highly reactive and can be quite damaging on the human tissue – hence why antioxidants are good for you. In medicine, there is a concept called oxidative stress which reflects an imbalance between the manifestation of reactive oxygen species and a biological system’s ability to readily detoxify the reactive intermediates or to repair the resulting damage. 

They found that in patients receiving treatment for depression, levels of malondialdehyde were significantly reduced. The team also discovered that levels of antioxidant substances in depressed patients climbed back to normal when receiving treatment for their condition (these antioxidants include zinc and uric acid).

There has been plenty of evidence pointing to depression and an association with other health issues.

Heart disease and depression. One recent study spanning 13 years found that depressed patients were 4.5 times more likely than others to suffer a heart attack, and another found that depressed patients faced more than three times the risk of death shortly following an attack.

Cancer and depression. The National Institute on Aging shook up the medical world with the results of a remarkable study: Tracking 4,825 people ages 71 and older, researchers found that those who were chronically depressed for at least six years had an 88 percent greater risk of developing cancer within the next four years.

Hypertension and depression. A study from the Centers for Disease Control and Prevention (CDC) provides compelling evidence that depression and anxiety can play a major role in triggering the condition. The landmark CDC study got its start in the early 1970s with thorough psychological testing of nearly 3,000 adults with normal blood pressure. When researchers checked the blood pressure and medical records of the subjects between seven and 16 years later, they spotted a remarkable trend: People suffering from either severe depression or anxiety at the start of the study were two to three times more likely than the others to develop hypertension.

All these studies prove that depression affects the whole human organism, not just the mind, and a better understanding of that would help scientists in discovering future treatments.


  • Jiménez-Fernández Sara et al. Oxidative Stress and Antioxidant Parameters in Patients With Major Depressive Disorder Compared to Healthy Controls Before and After Antidepressant Treatment: Results From a Meta-Analysis. The Journal of Clinical Psychiatry – Published 2015.
  • 20 Januar 2016
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