A lot of times, when you do something wrong, it's because you're crazy, not because you're sinning. You operate from a place of poverty when you're crazy, but from a place of wealth when you're sinning. Sometimes people use the place of wealth as a way to mask their sense of poverty -- I'm not sure what to think there.
Does God care only about your intent, or also about your actions themselves? I think both can go against his preferences. So while you may have been crazy when you did something desperate to someone else, which harmed them, if you don't do anything about being crazy, maybe that is a problem of intent, since you may not have regard for God's feelings (nor the human victim's).
There's a connection between mental health and holiness. Holiness involves mental health. But mental health by itself does not cause you to be or become holy, to love God or set yourself apart for him.
There's a lot out there about mental health, by qualified people. I think it's important to add to what they say a concern with integrating God into your mental health practices, so that they do not become purely humanistic.
For instance, practicing journaling can be a way to understand how your life works, so that you can make interventions to reduce mental problems. You might want to evaluate different areas of your life, to see what situation you are in. One of those areas can, or should, involve God. So you might say, "What's the situation? in financial, mental, physical health, in my relationships with humans, with God". You are interested not only in mental health, but in your whole life.
By talking about what they talk about, and not about what they don't, thought patterns can imply that there is this, that, and no other thing, though they don't rule those other things out explicitly. Something to avoid is a vision of life that doesn't include God, explicitly or implicitly. Perhaps it is good to bring God's existence to mind whenever you try to use some sort of therapeutic technique on yourself, or whenever you visit a therapist. This technique of remembering God can be applied to other pursuits, such as thinking. (Thinking in partnership with God can itself be therapeutic.)
We find our treasure in what we work for, and our life of securing what we treasure becomes our real life. So if we do not make our pursuit of mental health theistic in some way, we will fail to develop our connection with God in that part that seems so real to us. We treasure our well-being -- and what else?