However, the hippocampus does much more. It is also central
to context- dependent memory, which is the fact that it’s easier to remember things that relate closely to your current situation.5 For example,
it’s easier to recall memories from your undergraduate days if you’re
visiting your old college campus, because the context is the same.
Unfortunately, in depression, there is a large downside to context-
dependent memory. Because the “context” is depression, all those
happy memories that are easy to recall when you’re in a good mood
suddenly evaporate. Meanwhile, all the tragedies in your life
become too easy to remember.
In depression, the hippocampus not only shows abnormal
activity but also tends to be smaller in size.6 The small hippocam-
pus is likely the result of chronic stress, which can damage and kill
neurons. Depression is stressful and thus disrupts the proper func-
tioning of the hippocampus. Fortunately, it’s possible to grow new
neurons in the hippocampus, and we’ll cover that later in the book.