Dear friends, This is my first post, excuse me if it's a bit wordy. Anti-psychotic meds are used for their effects on the dopamine system, but they also have strong anticholinergic side effects. Along with dry mouth and constipation, they can cause quite a lot of drowsiness. Now, dopamine is usually activating, so there is a tug of war with these meds between activating effects and sedating effects. When a med like Seroquel is given in low doses, the anticholinergic effects win. In higher doses, the dopimanergic effects win. Seroquel is frequently used off label in low doses as a sleeping agent, so not every patient who takes this med for sleep has psychotic problems. A person can develop tolerance to the drowsiness, just like tolerance to Benadryl when it's used for insomnia. However, many take this medicine for long periods and find it very helpful for sleep. And now, I'm going to catch some zzz's myself!