Anybody who has a close friend that suffers from monophobia is likely going to want to do everything that they can to help them to deal with it. The most important thing that you can do is to be supportive but there are also some more concrete steps that can be taken as well. Knowing how you can be of help will make it a lot easier to deal with a friend who is afraid to be alone.
One of the challenges of helping somebody to get over a fear of being alone is that most of the time the way that we help people with issues is by being there for them. This of course presents a problem since getting over monophobia requires that that people learn to be by themselves. That being said there are things that you can do that will help people to get over their fear of being alone.
The first thing that you can do to help a person who is suffering from monophobia is to make sure that they are aware that there is help available. There are support groups that allow people to get together with other people who have the same problem and discuss it. For a lot of people knowing that you are not the only one going through the same thing and hearing how other people are dealing with the problem can be a big help.
Another way that you can help a friend with monophobia is by encouraging them to seek therapy. Like most phobias monophobia is usually the result of sort of childhood trauma, the best way to get over it is to find out what the cause is and then work to change the beliefs that have led to it. Most mental health professionals are able to help people with monophobia so it is a good idea to encourage your friend to seek help.
One last way that you can help a person who has a monophobia is by working with them to face their fear. Any form of treatment is going to require that they slowly become desensitized by actually being left alone. In the early days they will only be left by themselves for a short period of time. They will need a friend who is located nearby who will be able to come and get them if they have a panic attack. Being that friend can go a long way to helping deal with their monophobia.