Os transtornos de humor são mais comuns em pessoas com anormalidades na secreção de melatonina

Neste estudo foi analisada a correlação entre os transtornos afetivos e o volume da glândula pineal. O estudo constatou que os trastornos afetivos, tais como transtornos de humor (depressão e mania) e transtornos de ansiedade,  têm sido associados a alterações nos ritmos circadiano devido a alterações na secreção de melatonina pela glândula pineal; especialmente entre pacientes com um volume reduzido da glândula pineal.

Foi ainda demonstrado que tratamentos destinados  a regularização dos ritmos circadianos pode ser útil para melhorar o humor em pessoas jovens com perturbações emocionais.

Articolo in inglese

Pineal volume and evening melatonin in young people with affective disorders.

Brain Imaging Behav. 2016 Nov 3;

Authors: Carpenter JS, Abelmann AC, Hatton SN, Robillard R, Hermens DF, Bennett MR, Lagopoulos J, Hickie IB

Affective disorders in young people have been associated with disruptions in circadian rhythms, including abnormalities in secretion of the pineal hormone melatonin. Previous research reports relationships between pineal gland volumes, melatonin secretion, and sleep-wake cycles, but the relationship between these factors has not been explored in affective disorders. This study aimed to characterize these factors and explore associations with mood symptoms and functioning in a sample of young people with affective disorders. Pineal volume from magnetic resonance imaging and melatonin assay from evening dim-light saliva collection were evaluated in 50 individuals (15-30 years old; 72 % female) with bipolar, depressive, or anxiety disorders. Actigraphy monitoring was also conducted for approximately two weeks to derive sleep-wake measures. Pineal volume was associated with melatonin secretion across the evening, replicating previous findings in psychiatrically healthy individuals. Pineal volume was smaller in participants in which melatonin onset was not detected. Timing of melatonin secretion was related to sleep timing, but amount of melatonin and pineal volume were not related to any sleep-wake measures. A shorter phase angle between onset of melatonin secretion and sleep onset was associated with longer total sleep time. Lower melatonin levels were associated with poorer social and occupational functioning. Although pineal volume is not directly related to sleep disturbances or symptoms, melatonin may influence both sleep-wake cycles and functioning in the early stages of affective disorder. Causal links remain to be established, however, treatments that target circadian rhythms may be useful in improving functioning in young people with affective disorders.

PMID: 27812851 [PubMed - as supplied by publisher]