Histamine is a biologically active amine which is involved in immune responses, the regulation of the gut and acts as a neurotransmitter. Imbalances of histamine have been implicated in allergies, schizophrenia, depression, anxiety, behavioural disorders and autism.

Histamine is most well-known for its involvement in allergic reactions, however it also acts as a neurotransmitter like serotonin and dopamine. Histamine is involved in the wake-sleep cycle and is required for arousal, alertness, learning and memory. It also regulates appetite, other neurotransmitters and the perception of pain.

Histamine imbalances, both low and high are known to be involved in mental health issues. Histamine is required for arousal and helps regulate some stress hormones. Patients with low histamine levels have been described as having depression, poor motivation, anxiety and issues with self-mutilation. High histamine levels have been observed in patients suffering from schizophrenia, obsessive-compulsive disorders, anorexia, bulimia, autism and depression. High histamine level may run in families and these patients are more likely to have allergies, headaches, obsessions, phobias and be more sensitive to pain; symptoms consistent with histamine’s role in the body.