Which of the following describes an affective disorder?

An affective disorder is characterized by significant disturbances in a person's mood or emotional state, which can lead to various extremes. The correct answer highlights the hallmark of affective disorders, including conditions such as bipolar disorder and major depressive disorder, where individuals experience dramatic fluctuations in mood. These can manifest as periods of intense elation or mania, contrasting sharply with episodes of deep, disabling depression.

Understanding mood disorders encompasses recognizing these emotional extremes. The other options do not accurately reflect the nature of affective disorders. Consistent mood stability indicates an absence of significant mood changes, which is not characteristic of affective disorders. A stable mood with occasional irritability suggests minimal mood disruption, not the pronounced swings typical in these disorders. Lastly, having only depressive episodes without instances of elation describes a specific type of mood disorder (like unipolar depression) but does not encompass the broader spectrum of affective disorders that also include manic or hypomanic states. Therefore, the emphasis on the extremes of mood variability captures the essence of what defines affective disorders.