Varys was diagnosed with major depressive disorder seven years ago. Varys knows his mother took medicine to combat depression and he worries his son will experience depression too. Why?

Because he fears that depression is an inherited disease.

Explanation:

Varys is depressed and knows that his mother suffers from the same disease, he fears the disease is hereditary and could be passed on to his son as a genetic factor. Some types of depression are genetic in origin, caused by an inherited biological vulnerability. However, this genetic inheritance is not a determining factor for developing the disease. Additional factors such as stress at home, work or school contribute to your onset of depression. People who do not carry this genetic heritage can also develop depression. In either case, hereditary or not, it is associated with changes in brain structure or function.