I had one family member who was 'depressed' after the death of another family member, but I decided to wait until his 7-yr old twins went off to college until I started a new generation.
One great way to get to the bottom of the problem is to click on 'details' and take a look at exactly what's causing the problem. Make sure there are plenty of different groceries in the fridge and that your peeps are well fed.
Buy lots of candy and fruit and feed it to them often; if their health is low, multivitamins and fruit will help them recover. If their bar shows 'a bit sick', it might help to give them the right medicine and give them a doctor's consultation if necessary.