This is a small case series of patients with refractory neuropsychiatric disorders such as depression, anxiety, OCD, ADHD and more, who experienced significant improvement after subsequent diagnosis and treatment of MCAS. While the average person still thinks that histamine for example is just something related to allergies, let’s not forget that histamine acts as a neurotransmitter in the brain, influencing things such as arousal, attention, mood, sleep, and motivation. So when levels build up it can create: -Restlessness and physical + mental hyperactivity -Difficulty concentrating, brain fog, inattention -Irritability, impulsivity, or agitation -Sleep disturbances (insomnia or poor sleep quality) -Anxiety or sensory sensitivities -Hyper arousal -Racing thoughts, anxiety/panic, or restlessness -Insomnia or disrupted sleep cycles (common in manic phases) -Depressive symptoms (fatigue, brain fog, low motivation) during crashes -Emotional lability or energy fluctuations Of course, we don’t pull all these out of our asses. There are more reports noting that histamine flares can mimic manic/depressive episodes, and MCAS patients sometimes receive initial bipolar diagnoses.