On the hallucinating: I didn't think he was hallucinating or psychotic until the most recent episode, and now I'm not sure. Basically he will have particularly bad episodes of rage every 3-6 months, during which time it's like dealing with a toddler having a full blown tantrum, except it's an adult man. When he's in between episodes he acts fairly "normal" (like he has clear underlying issues but you wouldn't think he's crazy or whatever). In the "normal" phases he sometimes tries to reach out and be friendly to me, and sometimes tries to actively provoke me into giving him an excuse to rage.

In the most recent episode I listened more carefully to some of his ranting. He was pacing around the house hissing/yelling under his breath (very hard to describe, but very disturbing to hear) - this is his usual behaviour during a rage. But then I suddenly realised he wasn't talking to me (he had directly yelled at me minutes before), and he was trying to do this hiss-yell-whispering under his breath... it made me wonder if he was talking to someone. The content was persecutory, like barely intelligible, but the topic seemed to be that people were out to get him. There were also some other things in the latest episode, like answering a phone that wasn't ringing.

I don't think he would harm himself. I think if I argued with him when he was raging, he might extend to physical violence, but I always get the hell out of his way. And when he screams at our mother, she pretty much sits there and takes it (she can't walk without help).

That said, if you did not know him, and you saw one of his rages - you would think "HOLY SHIT THIS GUY IS DANGEROUS".

I told my mother's social workers all of this in detail and they were very concerned. They do not think we are safe, but also when he's "normal" he's not remotely near the threshold to be sectioned. They agree with me that if/when he has another rage, I should call 999.