i became severely depressed. lashed out at my friends, spent hours upon hours thinking about commiting suicide, and even more time plotting out ways to cut myself. couln't feel strong emotions, if i was lucky enough to have a moment where i wasn't sad. Positive emotions were very fleeting, and i would start crying or become enraged for the most trivial reasons.
i've been taking zyrtec for 6 years, my depression set in after i turned 13. been off zyrtec for less than a week. i feel a little bit better already.