What is seasonal affective disorder often linked to?

• A. Excessive sleep
• B. Infradian rhythms
• C. Circadian disruptions
• D. Genetic mutations

Answer: (B)

Seasonal affective disorder (SAD) is a type of depression that typically occurs during specific seasons, most commonly in the winter months when daylight hours are shorter. This condition is often linked to infradian rhythms, which are biological rhythms that last longer than 24 hours. Infradian rhythms include seasonal cycles, such as the changes in mood and behavior that many individuals experience with the changing seasons.

SAD is thought to be influenced by changes in light exposure that are related to these seasonal cycles. The lack of sunlight during the winter months can disrupt normal biological processes, leading to symptoms associated with this disorder. Light exposure plays a crucial role in regulating mood through various neurological pathways, including the modulation of serotonin levels, a key neurotransmitter affecting mood.

This connection to infradian rhythms highlights the importance of temporal biological changes and the external environment (like seasonal variations in daylight) in the development of SAD, making this the most relevant and accurate choice among the options provided.