There can be many underlying causes for various health issues.  With a symptom-based, conventional medicine approach, the treatment for depression is mainly singular – raising levels of feel good brain chemicals.  With a systems-based approach, functional or naturopathic medicine, the focus is on looking at what’s causing the feelings of low mood.  For example, do you have food sensitivities (e.g. gluten, dairy, etc) that are linked to mental symptoms like depression? Do you have low thyroid function? Are you deficient in omega-3 fats which make up the fat tissue of the brain? Are you lacking vitamin B12 – which helps metabolize homocysteine, playing a key role in depression? Do you have heavy metal toxicity (e.g. mercury) that can cause mood and neurological issues? Are you deficient in vitamin D? Are you chronically sleep deprived? Do you have insulin or cortisol imbalances? Do you have underlying digestive issues (e.g. leaky gut, IBS, pathogens, etc)? You get the idea. The point of this is to give you information, but mainly some insight into how many issues are multi-factorial and a resolution depends on identifying and treating the cause(s) for each individual.