Are you taking any medication for depression?
Be aware of interactions, how to taper off, a good article by Dr. Georgia Ede: https://www.psychologytoday.com/us/...ric-medications
Apparently a schizophrenic med can lower HDL, https://www.psychiatryadvisor.com/h...-schizophrenia/ so check the side effects on Drugs.com of any medications in this class. Unlikely, but if you are on any medications, it doesn't hurt to check both the Common and Uncommon side effects...always long lists, sometimes with surprises. And if your stats are correct, your BMI by itself, and still having metabolic syndrome, can be a risk factor for low HDL.