I am posting here because my dad has a history of manic episodes and has been diagnosed with bipolar disorder by a professional but his symptoms could be something else. He currently lives in a different city from me so I'm looking for advice on what I should do.

The other day he told me that someone was trying to break into his apartment but since then I have started to think that he is hallucinating and paranoid. Just the stuff he says doesn't make sense and this has happened before in the past. He called me last night to say that he was sitting at the train station because he was afraid to stay home. He said he could hear people standing outside talking about how they were going to try to get into his apartment again but he has never actually seen these people. He also believes that his landlord is in on the whole thing so he won't tell anyone else and won't call the police.

Should I notify his doctor? Or call someone? I'm worried he will just abandon the apartment and he is recovering from cancer right now and will inevitably end up homeless if this continues.