Depression is medically classified as a mood disorder. Even by that definition, it sounds aloof and hard to pin down to a specific set of criteria — which is exactly the case when it comes to depression. There is no single lab test that will tell a doctor if a person suffers from depression. That means that there is no singular cause.
Instead, many things can contribute to depression, including biology, life events, and more. It also means that depression can manifest in different ways. It is not always treated the same way medically, and it can be a vastly different experience for each person going through it.
All of that said, there are well-known underlying causes of depression, and we’re going to cover them.
1. Brain Chemistry
Perhaps the best-understood cause of depression is serotonin regulation. Serotonin is a chemical in your brain that helps neurons communicate with each other. If your brain produces too little serotonin, or if it is metabolized too quickly, the lack of this important chemical can cause depression.
When depression symptoms can be linked to serotonin regulation, the most common therapy is with serotonin reuptake inhibitors. These medications help patients retain more of the chemical in order to combat the underlying cause of depression.
Genetics can make some people much more susceptible to depression. Some genetic causes are being unraveled, and others remain a mystery to researchers. One example is a small hippocampus. This is a region in the brain, and in some people, it is smaller than others. Researchers believe that in at least some cases this is genetic.
A smaller hippocampus results in having fewer serotonin receptors in the brain as a whole, and that can contribute to depression. Other genetic causes are less understood, but it does seem to be the case that depression can run in a family.
3. Life Events
Events in a person’s life can cause depression. It’s easy to imagine how major trauma can instigate a mood disorder. Incredible loss and grief, as well as experiencing terrifying situations can cause changes in the brain, and those changes can very easily lead to depression.
But life events don’t have to be “major” to trigger a mood disorder. Stress alone can cause depression. Chronic stress has a high correlation with depression, but even large short-term increases in stress can end with a mood disorder.
It surprises very few people that drugs can cause changes in behavior. This applies to unregulated street drugs and well-regulated prescription medications. Opioids are one of the most common culprits. They dramatically impact mood, and they can create powerful disorders.
Many medications can cause depression as a side effect. In general, if you ever experience a change in mood after taking a new medication, you should talk to your doctor right away. Even if the change in mood feels positive, it’s something that needs to be monitored.
It seems unfair, but the changing of the seasons can cause depression. Seasonal depression is quite common, and it tends to happen during the transition from fall to winter. The months with less sunlight are associated with a sharp rise in depression cases.
6. Other Medical Problems
If life events can cause depression, then surely medical issues can do the same. Injuries can impact mood and lead to depression. Some brain injuries can cause major changes to mood and brain activity.
Outside of injury, many illnesses can lead to depression. Stroke, cancer, and other major medical problems have a high association with depression. Thyroid issues can mess with hormone regulation on many levels, and depression is a common outcome. Most doctors will screen for depression upon diagnosing a separate medical issue. This is because they are aware of the strong correlation and want to help patients avoid compounding problems.
The causes of depression are numerous, but that doesn’t mean that the situation is hopeless. There are many treatments and therapies that help patients with depression. If you or someone you love is struggling, help is available. Contact Prime Behavioral Health for a consultation and learn more about how you can overcome depression.