Fish oil supplements worsened my depression. I've tried them all, high dose, low dose. They all make me feel flat and depressed. When I stop taking them it lifts within a day.
My body was not made with fish oil. My mother did not eat fish when I was in the womb (she's allergic), and I did not eat fish growing up (I hated it).
I hope this is helpful to others who have had bad results with fish oil.