Histamine is most commonly known for its role in allergic reactions, but it is also involved in neurotransmission and can affect your emotions and behavior, as well. Histamine helps control the sleep-wake cycle and promotes the release of epinephrine and norepinephrine. High histamine levels have been linked to obsessive compulsive tendencies, depression, and headaches. Low histamine levels can contribute to paranoia, low libido, fatigue, and medication sensitivities.