Yes it can help. Fish oil
and some fatty fish contain a lot of omega 3 oil which is an essential nutrient.
About 50% of the brain cells are made up of essential fatty acids so a deficiency affects the brain. If you eat more fish, be sure it is wild caught e.g. Wild salmon as farmed fish have lots of contaminants. For fish oil get molecularly distilled type so it is free of pesticides etc.