Bipolar Disorder - Is Lamictal a necessary drug to take along with Abilify? It's an anti-seisure?

Yes you are correct but lamictal (lamotrigine) is also used as a mood stabilizer.
I am bipolar, and have taken it in the past.

You really should ask your Dr that question, he's the only one with the accurate explanation for his/her actions, decisions and prescriptions.

Hi, Suska! Anticonvulsant medications such as Lamictal and Tegretol, and the mood stabilizer lithium, have been used along with an antipsychotic to help control the mood swings of Bipolar disorder for decades.
I've taken them along with Abilify for years and they do a much better job than an antipsychotic alone.
Best wishes, WCV