Could a fall cause my mother to stop wanting to read and do cross word puzzles?

My Mother has stopped reading and doing cross word puzzles since she suffered a "fall" in the spring. Literally all she does is watch TV. I should add that since the initial hospitalization after 'fall' she needed to be in a rehab facility and is now in assisted living. Her abilities are not what they were both physically and mentally- depression and vascular dementia. What would cause her to show absolutely no interest in the few activities that she used to do?