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Photoperiod Manipulation

Meaning

Photoperiod Manipulation is the intentional, clinical adjustment of an individual’s daily light-dark exposure duration and intensity to deliberately shift or reinforce their circadian rhythm. This therapeutic technique involves using specific light protocols, such as bright light therapy in the morning or strict darkness in the evening, to treat conditions like Seasonal Affective Disorder, jet lag, or chronic circadian misalignment. It is a powerful, non-pharmacological tool used to reset the body’s internal clock and stabilize the rhythmic secretion of neuroendocrine hormones. The manipulation targets the phase of the circadian rhythm.