The Samaritans say:
Sometimes people get to a point where they feel they can’t cope, where it all gets too much to handle. It’s worse if people feel they are alone and can’t talk to anyone about what’s weighing on them.
Some things to look out for in others are:
Being irritable or nervous
A change in routine, like eating less or sleeping
Drinking, smoking or using more drugs than normal
Being more clumsy or accident prone
Losing interest in appearance or personal hygiene
Implying they would like to discuss something of importance.
Putting themselves down in a serious or jokey way, for example 'Oh, no one loves me', or 'I'm a waste of space' "