Welcome to HealthcareMagic forum,
I would want to tell you that these symptoms are common with Alzheimer's disease . Apart from the dementia
or memory loss
they have, they also suffer from what is known as cognitive behavior changes due to which they act in an unpredictable way .
You may have to consult a psychiatrist
for the same and review his medicines , the changes in the drug/ dose will take care of the problems and mood
Wish your family good health