How can you tell if mental illness is perpetuating itself, or if it's being caused by an unknown underlying health problem?

Holistic evaluation: All mental illness is related to stresses we encounter, our genetics ; physiological stress. A holistic doc can evaluate for possible contributing factors including nutrient deficiencies, environmental toxins, hormonal imbalances, food sensitivities, chronic infections ; imbalances of intestinal flora. These are important to address but emotional issues need to be addressed as well.