What class of drugs is used to treat bipolar affective disorder?

Mood stabilizers are the primary class of drugs used to treat bipolar affective disorder. This is because they help to control the extreme mood swings experienced in this condition, such as the episodes of mania and depression. Medications such as lithium, certain anticonvulsants (like valproate and lamotrigine), and atypical antipsychotics (which can also serve as mood stabilizers) are commonly used to maintain mood stability and prevent the recurrence of manic and depressive episodes.

While antidepressants and antipsychotics may sometimes be employed in managing specific symptoms or episodes in bipolar disorder, they do not primarily stabilize mood in the same way that mood stabilizers do. Stimulants are typically used for attention deficit hyperactivity disorder (ADHD) and certain other conditions but are not appropriate for managing bipolar disorder as they can potentially exacerbate manic symptoms. Thus, the fundamental role of mood stabilizers in achieving long-term management of bipolar affective disorder justifies their designation as the correct answer in this context.