Olanzapine, often sold under the brand name Zyprexa, is an atypical antipsychotic which came into use during the 1990s. It’s prescribed for schizophrenia and bipolar disorder. We don’t know exactly how it works, but it blocks serotonin and dopamine receptors. Specifically, it targets the dopamine D2-receptors in the mesolimbic pathway, which are involved in locomotion, attention, sleep, memory, and learning.
The mesolimbic pathway is one of four dopamine-related pathways in the brain associated with pleasurable feelings, addiction, and psychosis. Olanzapine has an even higher affinity for the serotonin 5HT2A-receptors which are concentrated in the frontal cortex of the brain. These receptors are responsible for the hallucinogenic effect of drugs like LSD, and they are expressed in psychosis.
After five years of taking the drug, I have a few things to say about it. First off, the devil is in the dose. The maximum dose of 20mg is debilitating – you feel drowsy and sleep an abnormal amount of time. We often give a high dose like this to patients who are mid-psychosis, and their brains are most likely in need of a rest.
The side effects were worse in the beginning when I also drooled and had facial tics. I slept a minimum of 12 hours a night, couldn’t remember my dreams, and always felt exhausted. I also got incredibly hungry, so I put on quite a bit of weight when I started Olanzapine. For me, the hunger disappeared a few months in.
These days I’m on a lower dose of 10mg/day, and although I still sleep slightly more than most other people, I’m not experiencing any of the early side effects. In my case, it worked to stick with the medication, even though the first few months on it were far from brilliant. Then again, coming down from psychosis is in itself not a pleasant experience. I remember my dreams again, and the slight detachment and emotional numbness I feel might work to my advantage. After all, we live in a society that rewards sociopathic behavior.