Someone has gone missing

and his mother is, as always, worried.
I saw her yesterday. She had gone out into the front garden to look down their street, phone in hand, hoping he would appear.
Her son is a grown man but he has serious mental health issues. Every so often he simply disappears. Sometimes it is for just a few  days. More than once it has been for several months.
He knows how to disappear. He takes cash from his bank account. He takes his "pup" tent and his sleeping bag and he goes - on his pushbike. Nobody has ever been able to find out where he goes.
I suspect he doesn't go that far but the police, alert to his disappearances, have never found him. He can blend in with the environment in ways that nobody else I know can do it. 
I travelled on a local train with him once. We were going up into the hills behind us. I know better than to ask him any questions. He sometimes talks to me because I  do not ask questions. Questions make him suspicious - and angry. He volunteered he was going into one of our national parks that day. 
The park begins one side of the railway line and I was going to the other side. We both got off at the same stop. He is sufficiently socially aware that he actually helped me take my tricycle off the train. By the time I was outside the station he had disappeared  completely. There was no sign of him at all. I remember another passenger looking puzzled and saying to me, "Where did he go?"
He might be in the park now. 
It is what passes for winter here and it will be cold but it doesn't seem to worry him. A couple of weeks back, at a really low point, he was outside in nothing more than a singlet and shorts - nothing on his feet. He was talking to a light pole. I pedalled past without saying anything to him. You don't interrupt such "conversations" because he could turn violent.
His mother was worried then. She is more worried now. She is in her eighties. He is fifty something. He has been a problem since early childhood. Back then the other families in the street asked his parents to keep him apart from the other children because he would lash out for no discernible reason. The other children were frightened of him.
When he reappears he will be taken "into care" for a few weeks. His medication will be adjusted. He will be sent "home". The cycle will begin all over again. 
While he is in care his mother will have some respite. She can visit her other son and he will visit her. These things are not possible while this man is with her or missing. He will have nothing to do with his brother. The very sight of his brother sends him into a violent rage. He has injured his mother more than once because he believes she has had some contact with his sibling. His mental condition is such that he has never been convicted of assault. His brother is doing his best but the "mental health team" insist that this man is "better off at home".  His brother told me once that he did not believe this and that he was putting aside savings for when his mother could move "to somewhere safe and comfortable".
It is becoming too much for his mother to handle. 
   "I've tried Cat. I am getting too old for this. He frightens me more than ever. They keep telling me this is the best place for him to be but I want to sell up and go somewhere safe."
She is too old for this. She has the right to somewhere safe. This has to be about more than the "best place" for him. I doubt it is the best place for him anyway. It is simply the cheapest option, the option that allows others to wash their hands of the responsibility. For them it isn't about "safe" - and it should be.