That depends on the circumstances, not all of which may be in one's control.

However:

• Avoid triggers. Most things will vary in intensity depending on external stimuli, and if those things are able to be avoided, it can reduce the paranoia or anxiety or mood problems.
• Try to identify any potential underlying causes and address those. This is critical and often ignored by the medical machine. Cover up or masking problems isn't fixing them, and many times, things do have an underlying cause in psychology or even physiology.
• Focus on your physical health. So often, people with mental problems have lifestyles or habits that are harming physical health, which can exacerbate or even cause mental problems.
• Try to develop personal habits which help the problems instead of feeding them.