There is support available to people who are struggling with their mental health whatever the time of day. There are helplines, a drop in at the Samaritans 10am - 10pm, online chats, and good advice on several websites noted below to help in difficult times.
It can be hard to broach the subject of getting help with someone who seems to be struggling. The Student Minds link below has some good ideas for how to do this.
Always ring 999 if there is an immediate serious risk of harm.
During office hours, you can go to the Student Hub. The advisers won’t be able to discuss someone else’s affairs in any depth but they can support you to work out how you might be able to help or get help.
If you are in halls of residence and worried, there is always a member of staff on duty for you to speak to.
www.studentminds.org.uk have sound advice.
www.samaritans.org gives helpful advice if you are concerned that someone is suicidal.