How Stress Contributes to Depression
Depression is a mysterious disease, and that makes treatment particularly difficult. However, one thing is understood: in the complicated web of variables and interactions that create the conditions for clinical depression, stress plays a starring role.
Although genes, environment, and other difficult-to-control factors will influence your depression risk, you do have the power to limit the stress that’s feeding your mental suffering. Both positive and negative events can bring on sudden stress, or it can build up gradually, with daily trials and overwhelming obligations of a busy life. In any case, you must first understand your susceptibility to stress, and then manage it in a way that’s tailored to your personality and lifestyle.
The Biological Connection Between Stress and Depression
Some stress is helpful, and small bouts of it can actually keep you motivated and energized, but long-lasting stress is cause for concern. Severe and prolonged stress can come from a job loss, chronic illness, grief, or a major upheaval in your environment. In some people, this stress response continues even after the stressful event has passed, and the body begins to malfunction:
- Chronic stress leads to a chemical imbalance. Many chemicals are responsible for healthy emotional balance. Dopamine and serotonin are necessary to regulate processes like sleep and mood, but sustained stress will chip away at these important neurotransmitters. An ongoing stress response also means a consistent release of cortisol, a stress hormone that breaks down tissue. Experts suspect that too much cortisol can directly induce depression.
- Stress can induce chronic illness. Many studies have shown that chronic stress is linked to hundreds of diseases, from cancer and diabetes to IBS and fibromyalgia. Over 30% of people living with a chronic medical condition will experience symptoms of depression, and some will become clinically depressed. Physical changes brought on by the illness may trigger the depression, or it may stem from a psychological reaction to the stress of the illness.
- Stress shrinks the hippocampus. Studies have shown that stress slows the production of new brain cells, especially in the hippocampus – the center that impacts depression the most (along with the amygdala and the thalamus). One study published in The Journal of Neuroscience followed 24 women with a history of depression, and found that the hippocampus was 9% to 13% smaller in those that were currently depressed than those who were not.
A healthy brain is able to rebuild cells with a process known as neurogenesis, but a brain under stress can’t undergo this important process of regeneration. Ultimately, the chemical changes brought on by chronic stress will interfere with your brain’s function, and that can be difficult to reverse without a creative approach to stress management.
Next page: How stress impacts symptoms and tips for better stress management.