Many of the tools I’ve come up with for dealing with ADD are psychological. If your problem includes having difficulty quitting bedtime games, reading, whatever, try this.
I like to play games that will sharpen my aging brain. I set my Sleeptime to midnight/ 8 hours to get enough sleep, then set the timer for say, 30 minutes of game playing in the dark (fortunately, games don’t keep me awake). Sometimes I’ll take a pill before starting to play. When the timer goes off, I know that I’m running out of time, not for playing or reading, but for getting the sleep that will sharpen my aging brain! It helps to make plans for the morning so I can’t just tell myself I can sleep later – coffee dates, dr’s appointments, brunch dates.