Brain metabolism during mood episodes: which statement is most accurate?

• A. Rises in manic episodes and rises in depressive episodes
• B. Rises in manic episodes but falls in depressive episodes
• C. Falls in manic episodes but rises in depressive episodes
• D. Falls in both manic and depressive episodes

Answer: (B)

Brain metabolism reflects how actively neurons are using energy during different mood states. In manic episodes, neural circuits often show heightened activity, leading to increased metabolic rate. In depressive episodes, neural activity in key mood-regulating areas tends to be reduced, resulting in lower metabolic rate. Imaging studies, such as PET, frequently observe hypermetabolism in frontal and related regions during mania and hypometabolism in those same areas during depression. Therefore, the statement that metabolism rises in manic episodes but falls in depressive episodes best captures the typical pattern. While there can be regional variation and individual differences, this pattern aligns with how brain activity shifts across mood states.