Think Adrianna is unlikeable now, 90210 fans? She's about to get A LOT worse.

On upcoming episodes, this wannabe A-lister will discover exactly what was going on near the end of her relationship with Navid - i.e. her boyfriend getting it on with her BFF - and will seek revenge by forcing Silver to revisit her bipolar past.

After the gang returns from Spring Break, look for Adrianna to mess with Silver's medication. Teases Jessica Stroup to TV Line:

“The bipolar disorder is something she’s been medicating herself to fight against. Unfortunately, someone tampers with [the medicine], and stuff’s about to blow up!”