The short version: Recurrent episodes (particularly if occurs when under age 21) of major depressive disorder results in a reduction in the volume of the hippocampus.
What this means: People who have recurring depression are physically altered by the disorder. Which to me says it is really important to take depression seriously and treat it before it becomes a recurrent/chronic disorder. The article also mentioned that there may be a protective effect for those on antidepressant meds; however, more research needs to be done on that.
What are the consequences of a small hippocampus? Let’s go back to the basic anatomy and physiology. What does a healthy hippocampus do exactly? The hippocampus is involved with memory and navigation in the form of spatial memories. So people with a smaller and assumed less functional hippocampus would have difficulty with learning, making new memories and get lost frequently.
During physical therapy school, I was never officially diagnosed, but I suspect I was depressed. (Didn’t have time go see any professional about it, because school was so demanding.) Which would also explain why in reality my grades in that time were terrible. I physiologically could not learn well. And why my grades improved as my depression loosened its’ grip. I mention this example because 1) it’s applicable to the topic at hand and 2) the world as a whole needs to be more open about mental health issues. (The best way the get the world to change is to start with thine own self, am I right?)