I think depression with low carb is very individual. personally, there is a strong history of depression on both mother / father families. When I did LCHF the first time years ago, I found I had trouble with depression. Fast forward MANY years, I discovered 5-HTP which is a supplement that makes the building blocks of seratonin (low levels can cause depression) more available to brain. Seratonin is increased with carb ingestion which may be one reason people with depression self medicate with carbs. I use 5-HTO every night now and no probs with depression and Keto. May be placebo effect but dont really care. Risk/ benefit more than worth it to me.