Hi. Some supplements not specific to depression, may though help depression in some while maybe not in others (and some will find it makes them worse, while this happens also for some with depression specific recommendations).
There's the foreword and a caution to this approach, but I feel it may help some better than depression specific approaches. Depression can come from a mix of factors, such as stress and anxiety with other things, maybe even where the sufferer is unaware they have been stressed or anxious. It may also just be that a person is not feeling enough relaxation that their brain, mind and body needs, mostly in the head (so more of a neurological depression maybe), and never thought of this.
Over time, taking the Indian ayurvedic herb Ashwagandha can help. (It tastes horrible if you take it in powder form, but powder form is best, as it’s better to take quite a lot, and every day. Such as a heaped teaspoon, increasing from half that, increasing to one and a half teaspoons. Judge it yourself. You need to mix it with a little liquid and maybe have a small drink of something just after for the taste).
Other things to take (one or two with Ashwagandha is a good idea) are L-Theanine, GABA supplement (such as “True Calm” with an everyday, basic multivitamin), and high strength valerian.
It might be a good idea to take something which gives your body some impulse at the same time as these calming remedies for a while, or some days. (But the main thing is to 'bring down' the pace of the head particularly and increase obvious, felt calm periods). L-Carnitine on its own is a good one for some impulse. Maybe some MSM with food - it speeds up bodily functions of the main body, it could be that your head is too fast or unrelaxed for the body. But it's also good to get the odd bit of impulse when you're gradually calming the head - body..
The calming supplements are also definitely worth a try, I think, if you’ve already tried depression specific drugs & supplements. I think they also (eventually) can help you to “feel more yourself”. While serotonin related supplements & drugs such as St John’s Wort, 5-Htp or SSRIs (& other types of anti-depressant), though maybe making you feel short term “good”, can be an artificial feeling and away from the real you. (That’s not to say these are without use.)