Mental health issues quite probably effect every single person in the UK, either directly as a result from ones own suffering or indirectly from the knock on effects of someone elses suffering.
Mental health issues can effect anyone at anytime and although awareness is at an all time high, it is still incredibly difficult for many people to talk about openly, or even admit they have a problem which of course is the vital first step.
For excellent and simple practical advice I love rethink.org who have a site packed full of resource including an excellent pdf to help you know what to say to someone suffering which is always difficult.
Please go over and take a look, and if your loved one is suffering, then please do something. Get help, don't suffer alone. Please.
From www.rethink.org :-
National mental health charity: information, services & a strong voice for everyone affected by mental illness - challenging attitudes and changing lives.