I keep Seroquel on hand as a PRN, mostly as an emergency med when my depression gets really severe. In that case I'll take it until things get a little better again and I feel like I can manage without it, typically up to a few months. I'm hesitant to take a high dosage of Seroquel, but relatively low dosages of 150 mg have worked for me in the past.It doesn't fix the depression but it definitely takes it from severe to manageable.

I've also used low dosages (50 mg) for sleep when I'm having bad insomnia and I have to take a break from my lorazepam to prevent dependence. I don't like doing that, and in that case I don't take the Seroquel for more than a few days, then I go back to lorazepam. That works for me because I never take lorazepam for extended periods of time. Typically just 3 mg a week or so, spread over 3-4 days. I never use it for longer than one week in a row, or maybe two in exceptional circumstances. Then I quit for a while (at least a few days but preferably longer), even though it's hard sometimes. As a result I never get bad withdrawal and I only need the Seroquel as a PRN in times when the insomnia is at its absolute worst.