Those who have never experienced depression may think of it as no more than a bad case of the blues. We picture someone who is constantly sad or who attempts suicide. But this is merely the tip of the iceberg when it comes to depression symptoms. That this is a mental disorder that can also include physical symptoms that wreak havoc on the body as well as the mind.
Depression and the Immune System: A Close Connection
One of the places we see depression’s physical symptoms is the body’s immune system. It’s still unclear whether malfunctions in the immune system cause depression or depression causes the immune system to malfunction. But one thing is certain between the two.
When you think about it, this makes perfect sense. We’ve known for a long time that sleep, stress, diet, and social factors can have a huge impact on our immune system’s ability to function. And we’ve also been aware that excess stress, changes in sleep, changes in appetite, and social isolation are classic symptoms of depression. Is it so much of a leap then to understand that these are closely linked?
One study suggests a connection between stress, depression, and immune function. In this study, mice who were repeatedly exposed to stress developed an immune response that released inflammatory proteins into the system. This inflammation caused atrophy and impaired responses in part of the brain, which in turn lead to common depressive behaviors. This chain reaction is highly suggestive of a cause-and-effect relationship linking stress, immune function, and depression.
When considering cause and effect, there are three possibilities that may explain the tie.
- Depression may weaken the immune system and cause increased susceptibility to illness.
- Major or long term illnesses may cause mood disorders such as depression.
- In some cases, illnesses or conditions may be caused by the same triggers as depression.
Each of these possibilities is equally likely, and there currently isn’t enough evidence to clearly discern which is most common. But what does the connection mean for those who struggle with depression or illness?