The most dramatic and direct effect of depression on health is suicide. An estimated 15% of those with major depression will die at their own hands. And while suicide is the most newsworthy and serious consequence, there are a host of less than fatal health effects.
Stress and anxiety associated with depression is well known to contribute to many major illnesses. Headaches, upset stomach (acid reflux and possible ulcer), high blood pressure, difficulty sleeping and increased risk of stroke and heart attack have all been linked to elevated stress levels.
Of the six leading causes of death by disease, stress raises the risk for all of them: cancer, heart disease, lung disease, cirrhosis and even accidents.
Is depression a cause or an effect?
Because depression doesn’t cause these diseases but only adds to the harm they do, it is hard to blame depression directly. To complicate matters, being ill is a risk factor to becoming depressed in the first place.
However, for those over 55 who are diagnosed with depression, the risk of premature death four times greater than those without depression. (This includes unipolar and bipolar types of depression.)
One study out of Sweden compared mortality rates for more than 50,000 patients with either unipolar or bipolar depression. They found: “Compared with the general population, suicide was 15 times more likely in bipolar males, 22 times more likely in bipolar females, 21 times more likely in depressed males, and 27 times more likely in depressed females.
Patients also died from natural causes significantly more often than did individuals in the general population; bipolar patients and unipolar women were particularly prone to death from cardiovascular, respiratory, and cerebrovascular causes.”
Along with these health risks, those who are depressed are much more likely to turn to alcohol or illegal drugs in an attempt to escape their symptoms. Addiction then presents with further health effects as a consequence of the original depression.
The attempt to relieve stress, anxiety and depressive symptoms then becomes harmful as the compulsive behavior takes over. The obsessive behaviors can revolve around eating, gambling, the Internet, shopping, sex, alcohol or any of a number of habits used to mask and evade stress or depression.
Unfortunately, these strategies only work in the very short term. Soon the addiction becomes just another source of anxiety, stress and depression. The distressed person becomes trapped in a vicious cycle and many who seek treatment for substance abuse also suffer from underlying depression.
Other health effects from depression are a consequence of just not caring about health anymore. A failure to eat properly, get enough exercise and abandoning a regular sleep schedule all contribute to lowering overall health.
While not specifically shown, it is likely that the immune system suffers, making untreated depression a pathway to infection.
In short, depression doesn’t cause immediate damage to health (other than suicide). Rather, the disease contributes to many other health problems and can lead to a long term slide into poor health.