What is the characteristic feature of cyclothymia?

Cyclothymia is a mood disorder that features a chronic pattern of emotional highs and lows that are not as severe as those seen in bipolar disorder. The defining characteristic of cyclothymia is the presence of hypomanic episodes—where individuals experience elevated mood, increased energy, or irritability—and periods of mild depression lasting for an extended duration, specifically at least two years.

These mood fluctuations do not meet the criteria for full-blown manic or major depressive episodes but still represent a persistent pattern that can affect the person's functioning and quality of life. The chronic nature of these symptoms distinguishes cyclothymia from other mood disorders that may involve more severe mood changes or shorter-duration episodes. Hence, the correct answer appropriately identifies the key features of cyclothymia, encompassing both the hypomanic and mild depressive phases over an extended period.