Works for some. Another drug, that works well for some people, & doesn't work for others. In my expereience it doesn't work as often as the stimulant meds, but if people can't tolerate the stimulants, it is nice to have this option. It does need to be taken on an increasing dose over about a month. If it does work, it works most of the day from just one dose. Like an antidepressant, you need it in your system.
Different system. Strattera (atomoxetine) is an antidepressant working mostly by increasing norepinephrine activity, while stimulants work (we think) through dopamine. When it works (40-45% of time vs 65% for stimulants), benefits are comparable, but side effects are quite different. Also, it must be taken daily and takes time to begin having an effect; but the effect then last all day. Sometimes, it is used with a stimulant.