Methylfolate is the only form of folate that crosses the blood-brain barrier. It activates the enzymes your brain needs to produce dopamine, serotonin, and norepinephrine. Without adequate methylfolate, your brain cannot manufacture these neurotransmitters. This is why you feel empty, exhausted, and emotionally unstable in recovery. Your brain is literally starving for the raw materials it needs to make the chemicals that regulate mood, motivation, and reward.