The same rules apply as with the initial adjustment period, so to be fair, you should give the
medication another 4-6 weeks after your
dosage was increased. Many times improvements can be seen before that, but to be safe, being that everyone responds differently to medications, 4-6 weeks will ensure you've given it ample time.
If after that time, you STILL aren't seeing improvements, then it's definitely time to speak with your doc and reevaluate your regimen.