Melatonin Sensitivity to Dim White Light in Affective Disorders

Nathan, Pradeep J.; Burrows, Graham D.; Norman, Trevor R.

doi:10.1016/s0893-133x(99)00018-4

Cited by 108 publications

(62 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Other studies showed, in addition to the main peak in spring/summer, a lower frequency of manic involuntary admissions in autumn (Cassidy & Carroll 2002;Lee et al 2002;Morken et al 2002;Volpe and Del Porto 2006;Lee et al 2007;Volpe et al 2010;Yang et al 2013;Geoffroy et al 2014). Furthermore, patients with bipolar disorder and seasonal-affective disorder have a higher light sensitivity compared to healthy controls and patients affected by major depressive disorder, as a result of melatoninergic, serotoninergic and dopaminergic neurotransmissions (Nathan et al 1999;Quera Salva et al 2011). Moreover, another factor influencing environmental regulation of biorhythm is represented by changes in photoperiod through different seasons (Abreu & Braganca 2015).…”

Section: Discussionmentioning

confidence: 95%

Involuntary admissions in Italy: the impact of seasonality

Aguglia

Moncalvo

Solia

et al. 2016

International Journal of Psychiatry in Clinical Practice

View full text Add to dashboard Cite

Objective: The aim of this study is to assess the prevalence of involuntary admissions with regard to seasonality and clinical associated features, in a sample of patients admitted to a psychiatric unit in a period of 24 months. Methods: All subjects consecutively admitted to the Psychiatric Inpatient Unit of the San Luigi Gonzaga Hospital, Orbassano (University of Turin, Italy) from September 2013 to August 2015 were recruited. Socio-demographic and clinical characteristics were collected. Results: Seven hundred and thirty admissions in psychiatric ward were recognized. The prevalence of involuntary admission was 15.4%. Patients with involuntary hospitalizations showed a higher education level, a higher prevalence of admission in spring/summer with a significant peak in June, a longer duration of hospitalization and a lower suicide ideation. Among involuntary admissions, physical restraint and suicide attempts were more prevalent during spring compared to the other seasons. Conclusions: Seasonality has an important role in the psychopathology of psychiatric disorders, particularly in bipolar and related disorder, and may represent an influencing factor in hospital admissions and hospitalizations. Seasonal pattern must be considered while managing diagnosis and treatment of mental disorders, with regard to prevention and psychoeducation of patients.

show abstract

Section: Discussionmentioning

confidence: 95%

Involuntary admissions in Italy: the impact of seasonality

Aguglia

Moncalvo

Solia

et al. 2016

International Journal of Psychiatry in Clinical Practice

View full text Add to dashboard Cite

show abstract

“…Thus, altered interaction between the SCN and the rest of the body could have repercussions on every level, from metabolic, circadian and sleep-wake rhythm dysregulations (due to hypothalamus-pituitary-adrenal gland axis malfunction), to altered and compromised immune response, to increased oxidative stress on a cellular level. 1,43 Furthermore, certain authors have indicated other climatic factors, such as humidity, day length, ultraviolet radiation and temperature, which represent a significant role in the admission of patients with bipolar disorder, particularly for (hypo)manic episodes. 21,35 Our study has several limitations: first, seasonal, environmental and/or psychological factors that could contribute to the onset of an acute clinical event (e.g., holidays, stressful life events, general medical condition, poor adherence to treatment, humidity, temperature, ultraviolet radiation) have not been taken into consideration and could not be ruled out as contributing factors.…”

Section: Discussionmentioning

confidence: 99%

Bipolar disorders: is there an influence of seasonality or photoperiod?

Aguglia

Borsotti

Maina

2017

Rev. Bras. Psiquiatr.

View full text Add to dashboard Cite

Objective: To increase understanding of the influence of photoperiod variation in patients with bipolar disorders. Methods: We followed a sample of Italian bipolar patients over a period of 24 months, focusing on inpatients. All patients admitted to the Psychiatric Inpatient Unit of San Luigi Gonzaga Hospital in Orbassano (Turin, Italy) between September 1, 2013 and August 31, 2015 were recruited. Sociodemographic and clinical data were collected. Results: Seven hundred and thirty patients were included. The admission rate for bipolar patients was significantly higher during May, June and July, when there was maximum sunlight exposure, although no seasonal pattern was found. Patients with (hypo)manic episodes were admitted more frequently during the spring and during longer photoperiods than those with major depressive episodes. Conclusions: Photoperiod is a key element in bipolar disorder, not only as an environmental factor but also as an important clinical parameter that should be considered during treatment.

show abstract

“…Interestingly, several studies have reported that BD patients are more sensitive to light than control subjects (von Knorring, 1978). In BD patients, lower light intensities are needed to suppress melatonin, and high light levels lead to more pronounced melatonin suppression (Lewy et al, 1981(Lewy et al, , 1985Nathan et al, 1999). Thus, increased responsiveness to light may further contribute to abnormal circadian rhythms in BD patients.…”

Section: Discussionmentioning

confidence: 99%

The mood stabilizer valproic acid opposes the effects of dopamine on circadian rhythms

et al. 2016

View full text Add to dashboard Cite

a b s t r a c tEndogenous circadian (~24 h) clocks regulate key physiological and cognitive processes via rhythmic expression of clock genes. The main circadian pacemaker is the hypothalamic suprachiasmatic nucleus (SCN). Mood disorders, including bipolar disorder (BD), are commonly associated with disturbed circadian rhythms. Dopamine (DA) contributes to mania in BD and has direct impact on clock gene expression. Therefore, we hypothesized that high levels of DA during episodes of mania contribute to disturbed circadian rhythms in BD. The mood stabilizer valproic acid (VPA) also affects circadian rhythms. Thus, we further hypothesized that VPA normalizes circadian disturbances caused by elevated levels of DA. To test these hypotheses, we examined locomotor rhythms and circadian gene cycling in mice with reduced expression of the dopamine transporter (DAT-KD mice), which results in elevated DA levels and manialike behavior. We found that elevated DA signaling lengthened the circadian period of behavioral rhythms in DAT-KD mice and clock gene expression rhythms in SCN explants. In contrast, we found that VPA shortened circadian period of behavioral rhythms in DAT-KD mice and clock gene expression rhythms in SCN explants, hippocampal cell lines, and human fibroblasts from BD patients. Thus, DA and VPA have opposing effects on circadian period. To test whether the impact of VPA on circadian rhythms contributes to its behavioral effects, we fed VPA to DAT-deficient Drosophila with and without functioning circadian clocks. Consistent with our hypothesis, we found that VPA had potent activity-suppressing effects in hyperactive DAT-deficient flies with intact circadian clocks. However, these effects were attenuated in DAT-deficient flies in which circadian clocks were disrupted, suggesting that VPA functions partly through the circadian clock to suppress activity. Here, we provide in vivo and in vitro evidence across species that elevated DA signaling lengthens the circadian period, an effect remediated by VPA treatment. Hence, VPA may exert beneficial effects on mood by normalizing lengthened circadian rhythm period in subjects with elevated DA resulting from reduced DAT.

show abstract

Melatonin Sensitivity to Dim White Light in Affective Disorders

Cited by 108 publications

References 27 publications

Involuntary admissions in Italy: the impact of seasonality

Involuntary admissions in Italy: the impact of seasonality

Bipolar disorders: is there an influence of seasonality or photoperiod?

The mood stabilizer valproic acid opposes the effects of dopamine on circadian rhythms

Contact Info

Product

Resources

About