I'm currently on .5 mg of Risperdal. I take it whenever I'm about to go to bed. From what the doctor told me it's supposed to slow down any sort of racing thoughts you might have and minimize obsessions. For me it's worked wonders. I feel like it's calmed me down at night. My thoughts aren't as obsessive as they used to be at night. It's used to treat many different kinds of mental illness and it can be very effective at treating certain types of anxiety.
From what I've read, this medicine has a particularly short half life. So it should get in your system relatively faster than a typical SSRI would.