Original:  Euthymia is also used to describe the baseline of other cyclical mood disorders like major depressive disorder (MDD), borderline personality disorder (BPD) and narcissistic personality disorder (NPD).
Revised:  Euthymia is also the baseline of other cyclical mood disorders like major depressive disorder (MDD), borderline personality disorder (BPD) and narcissistic personality disorder (NPD).
Edit intent: coherence