Undiagnosed; Hashimoto's Thyroiditis, Insulin Resistance, Small Intestine Bacterial Overgrowth (SIBO), food intolerances or allergies and leaky gut syndrome are just a few of the conditions that can cause anxiety and depression. How? Each of these conditions will, through various pathways lead to immune system up-regulation. The immune system can become overly aggressive and confuse your own tissues for antigen's (enemies). It can then cross the blood-brain barrier and cause inflammation of brain tissue. This may be expressed as anxiety and depression.
Functional Medicine providers look for the above conditions when presented with a patient with anxiety and depression, then work with them on diet, lifestyle and nutritional support in order to help them heal.