An insight into light as a chronobiological therapy in affective disorders

Abstract

Abstract:The field of chronobiology has vastly expanded over the past few decades, bringing together research from the fields of circadian rhythms and sleep. The importance of the environmental day-night cycle on our health is becoming increasingly evident as we evolve into a 24-hour society. Reducing or changing sleep times against our natural instincts to rest at night has a detrimental impact on our well-being. The mammalian circadian clock, termed "the suprachiasmatic nucleus", is responsible for synchronizing our behavioral and physiological outputs to the environment. It utilizes light transcoded by specialized retinal photoreceptors as its cue to set internal rhythms to be in phase with the light-dark cycle. Misalignment of these outputs results in symptoms such as altered/disturbed sleep patterns, changes in mood, and physical and mental exhaustion -symptoms shared by many affective clinical disorders. Key links to circadian abnormalities have been found in a number of disorders, such as seasonal affective disorder, nonseasonal depression, and bipolar affective disorder. Furthermore, therapies developed through chronobiological research have been shown to be beneficial in the treatment of these conditions. In this article, we discuss the impact of circadian research on the management of affective disorders, giving evidence of how a misaligned circadian system may be a contributor to the symptoms of depression and how moderating circadian rhythms with light therapy benefits patients.

Machiavellianism and psychopathy affect sleep quality in people with affective disorders and mentally healthy individuals

“…Particularly, sleep disturbances in AD are connected to increased symptom severity, illness duration (e.g., Gruber et al, 2011 ), and higher suicidality (e.g., Palagini et al, 2019 ). Contrary, affecting sleep rhythms has been found to positively impact the trajectory of AD, which is reflected by sleep deprivation and light therapy treatments, and sleep hygiene ( Walsh et al, 2014 ; Dallaspezia and Benedetti, 2015 ; Rahimi et al, 2016 ). Due to the role of sleep in the etiology and preservation of AD, it is necessary to understand the factors driving the relationship between sleep and AD.…”