A 41-year-old female with bipolar I disorder has been maintained on valproate 1,000 mg daily for the past 18 months following a severe manic episode. Her valproic acid level at this visit is 78 mcg/mL. She has had no manic or depressive episodes since starting valproate. She endorses stable mood, consistent sleep patterns, and return to full-time employment. However, she reports she has gained 22 pounds, notices her hair has become thinner, and has had two menstrual cycles that were irregular over the past four months. She asks whether the medication is still necessary. The PMHNP is evaluating treatment effectiveness and tolerability at this maintenance visit. Which evaluation best reflects appropriate clinical reasoning?