First, this would be theoretically an anxiety treatment, not a depression treatment. Second, never buy anything marketed over the internet or by TV ads. Third, the ingredients they're using shows they are just using inexpensive forms that don't absorb well -- the B12 is the cyano-form, which isn't absorbed well. The Calcium and Magnesium are both the least well absorbed, but cheapest, forms of both. And the advertising is incorrect -- none of the three herbs "increase" GABA or serotonin. Passionflower does target GABA, and is a good systemic relaxant, but it doesn't increase GABA, it in part targets receptors as benzos do but not as strongly and more safely. I don't think anyone knows how ashwagandha works exactly, but it's an adaptogen from ayurvedic medicine which is used for energy as well as an overall relaxant of the adrenal system --cortisol -- as its most important physiological response. (As with most adaptogens it probably also reduces blood sugar). L-theanine is another substance nobody knows exactly how it works, and it's seldom effective, but it does not act to increase GABA or serotonin. There are ways to increase GABA and serotonin, by taking the substances the body uses to make them, but almost nobody is low in these substances and that isn't the cause of the vast majority of cases of mental problems. What drugs and natural remedies mostly do is make these work in a stronger fashion (or, with drugs, in an artificial fashion) that can make you feel better but doesn't have anything to do with the cause of the problem. I wouldn't hesitate to recommend using ashwagandha or passionflower or magnesium, but I wouldn't use this company to do it. Your best health foods store has brands more likely to have better quality ingredients. By the way, I recommend for an overview of the subject Natural Highs by Hyla Cass, a psychiatrist at UCLA.