I think my dad who is 71 years old is developing patalogical jealousy that creates serious problems for my mom (she is 69) and himself. He started a year ago suspecting my mom in not being truthful to him somewhat 30 years ago. He is keeping investigating, searching and questioning people about my mom possible adultery (which is groundless) He does not sleep and lost a lot of weight He used to have uncontrollable shaking of his right hand and now it looks like he started having the same problem with his left hand. My brother and I live overseas, very far away from them - we are calling them almost every day and supporting them financially besides spending annual vocations with them - but they definitely feel lonely without us. I feel like my mom cannot take my dad behavior any more. So, considering the above... If my dad is having mental disorder can it be compensated by medicine? Can he be dangerous to the family members y himself? If one of us (my brother or I) moves back to live with the parents will it mitigate the symptoms?