Q: My father is irritable, and has stopped participating in activities he used to love. Is he depressed?
A: Irritability and loss of interest in activities a person used to enjoy are two symptoms of depression, but there could be other causes for these two problems. The symptoms are a cause for concern.
Encourage your father to see his regular doctor and describe the symptoms. You can tell you father that you are concerned because he doesn't seem to be having much fun lately, and offer your support in going to the doctor with him if he wants, but especially in following up if he doesn't make the appointment.
If Dad wants to go to the doctor by himself, suggest that he briefly write down some of your specific concerns while still on the phone with you. If depression is the reason for these problems, the good news is that it is successfully treated quite often in seniors.