Research covered by the BBC has suggested that folic acid may be a possible way to reduce depression. A variety of studies were reviewed that indicate a possible benefit of folic acid and are encouraging larger-scale studies to determine if this is the case. You can add this to the pile of other things that can possibly improve a depressed mood, but one thing I am always mindful of is how changing your mood does not address the actual issues related to experiencing depression. Thus, the long-term benefit for these types of substances will always be significantly limited.