I'm the only one she'll talk to and she has currently been diagnosed with severe depression and anxiety. She's on medication and is staying in a mental hospital, but it hasn't worked. She still cuts herself and wants to die.. She also believes that she serves the devil and he talks to her. He gets angry when me and her speak and then she get's scared and tells me she has to go because he'll get angry. What do I do? How can I make her strong again, and to be able to fight off the devil.. Although I know he'not actually communicating with her.. Help please?

She also believes that she serves the devil and he talks to her. He gets angry when me and her speak and then she get's scared and tells me she has to go because he'll get angry.

This does not sound like depression, this sounds like a mental disorder, in which case, antidepressants won't do the trick.

This young lady needs more help than you can provide.

She may never get well, but she definitely needs more help than she's getting, from professionals that know how to deal with mental disorders.

You can continue to care about her, and I think it's wonderful that you do, but there's very little you yourself can do to help her.

She's where she needs to be. They don't put people in mental hospitals for depression. There's more going on than you think there is, but give it time. Mental disorders aren't easily "cured". They need to find out what's going on, and treatment for a mental disorder, and her's is severe if she thinks the devil is talking to her, is not quick or easy. This isn't something that will be dealt with in days, weeks, even months. It could be years before she's better. It could be that she never completely gets the chance to lead a normal life.

I hate to give you bad news, but that's the reality of a mental disorder. You're going to have to be very strong to deal with this, and you're going to have to accept that your friend may never be completely okay.

The information provided by Alty is on point. The behaviors you describe are clear indications of psychosis (http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002520/) as opposed to depression. Even major depressive disorder (MDD) (http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001941/).

Irrespective of diagnosis or severity of disorder, emotional support is always an additive to recovery. So please continue to be attentive to your friend even though it may sometimes seem futile.

Experience has taught me that the attendance of loved ones far outweighs the benefit of any drug that can be administered by manifold.

If your friend cuts herself and thinks she is in touch with the devil, there is likely something more going on that 'just' a depression (even though in very severe cases, people with Major Depressive Disorder can get psychotic). Definitely, though, she will need to get proper medication, and that can be a very delicate balancing act for the doctors who treat her. Not all medication helps immediately, and some medication must be tested for a while to see how the person responds.