Until recently, many experts and neurologists claimed that chronic depression was caused by a change in the brain. But it’s now proven that brain damage doesn’t cause depression, but quite the opposite: chronic depression causes brain damage. Common symptoms of depression include mood swings, which are also accompanied by impaired cognitive function — difficulty remembering, difficulty making decisions, planning, setting priorities, and taking action. You can learn about teenage mental health on our website.
Depression is considered a chronic stress-related illness. People with chronic depression are known to often have a smaller hippocampus than healthy people. The hippocampus is an area of the brain that has an important role in the formation of new memories by processing memories for long-term storage.
Now a study published in the journal Moleculum Psychiatry has provided strong evidence that chronic recurrent depression does shrink the hippocampus, leading to loss of emotional and behavioral function. Thus, a person who is depressed continues to have difficulty remembering and concentrating even after recovering from the illness. Nearly about 20 percent of chronic depression patients never fully recover.
Depression increases the production of cortisol in the brain. Cortisol is a stress hormone that is toxic to cells in the hippocampus. Overexposure to cortisol in the long term is suspected of causing a shrinking of the size of the hippocampus, which in turn causes memory problems or difficulty remembering. But as the hippocampus shrinks, it’s not just a problem remembering Facebook passwords. You also change all sorts of other behaviors related to your memory. Therefore, shrinkage of the hippocampus is also associated with loss of normal daily functioning.
This is because the hippocampus is also connected to many brain regions that regulate how we feel and respond to stress. The hippocampus is connected to the amygdala which controls our experience of fear. In people with chronic depression, the amygdala actually enlarges and is more active as a result of long-term exposure to excess cortisol.
An enlarged and hyperactive amygdala, combined with other abnormal activity in the brain, can lead to disturbed sleep and activity patterns. It also causes the body to release a number of hormones and other chemicals and causes other complications of depression.