Two Kinds of Depression?

I'm no psychiatrist, but it was pretty clear to me that Jack was depressed. Over the past few months the sixty five year-old man had become withdrawn, irritable, had lost his appetite and had dropped fifteen pounds. I got this information from his wife, Connie, because at his first visit to my internal medicine practice Jack barely spoke and sat staring down at his hands.

In medical school I learned that there are two kinds of depression: the first kind, called "clinical," "endogenous," or depression with a capital "D," is caused by a chemical disturbance in the brain; the second kind, called "reactive," "situational," or depression with a little "d," can happen to anyone who undergoes stress or a serious loss.

Jack, who was happily married and contentedly retired, had experienced no recent stress or loss. Obviously, he had clinical depression--Big "D". I performed an exam and did some basic blood work and a chest x-ray but I felt confident that Jack would have no physical illness and would respond nicely to the antidepressant I prescribed. The next day, though, his chest x-ray came back with an unexpected finding: Jack had a large mass that would prove to be lung cancer.

I rethought my initial diagnosis. Maybe Jack's "depression" was his awareness, even if unspoken, that something was horribly wrong with him? Maybe his cancer had caused his poor appetite and weight loss? As the weeks went on and Jack started chemotherapy, though, his mood seemed to improve and I decided to continue the antidepressant. I suspect that Jack's improvement was due to some combination-impossible to parse-of the antidepressant, the treatment of his lung cancer, and the fact that Connie was ever at his side encouraging him. Maybe part Big "D," maybe part little "d?" Jack felt better and that would have to be answer enough.