Which disorder is characterized by multiple major depressive episodes without periods of high mood?

The correct answer is Major Depressive Disorder. This disorder is characterized by the occurrence of multiple major depressive episodes that significantly impact an individual's daily functioning. Each episode involves a sustained low mood, loss of interest in activities, changes in appetite or sleep patterns, and other symptoms indicative of depression. Importantly, individuals with Major Depressive Disorder do not experience periods of elevated mood or mania that are seen in other mood disorders; therefore, their mood remains consistently low during depressive episodes.

In contrast, Bipolar Disorder involves alternating episodes of depression and elevated mood (mania or hypomania), which distinguishes it from Major Depressive Disorder. Panic Disorder centers on recurrent panic attacks and heightened anxiety, and does not fit the criteria outlined in the question. Personality Disorders are a different category altogether, characterized by enduring patterns of behavior and inner experiences that deviates from cultural expectations but do not specifically entail the recurring depressive episodes described.