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OBJECTIVE: To confirm prior findings that the larger the maximum monthly increase in solar insolation in springtime, the younger the age of onset of bipolar disorder. METHOD: Data were collected from 5536 patients at 50 sites in 32 countries on six continents. Onset occurred at 456 locations in 57 countries. Variables included solar insolation, birth-cohort, family history, polarity of first episode and country physician density. RESULTS: There was a significant, inverse association between the maximum monthly increase in solar insolation at the onset location, and the age of onset. This effect was reduced in those without a family history of mood disorders and with a first episode of mania rather than depression. The maximum monthly increase occurred in springtime. The youngest birth-cohort had the youngest age of onset. All prior relationships were confirmed using both the entire sample, and only the youngest birth-cohort (all estimated coefficients P < 0.001). CONCLUSION: A large increase in springtime solar insolation may impact the onset of bipolar disorder, especially with a family history of mood disorders. Recent societal changes that affect light exposure (LED lighting, mobile devices backlit with LEDs) may influence adaptability to a springtime circadian challenge.
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Transtorno Bipolar/epidemiologia , Radiação Eletromagnética , Internacionalidade , Estações do Ano , Adolescente , Adulto , África/epidemiologia , Idade de Início , Ásia/epidemiologia , Austrália/epidemiologia , Europa (Continente)/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , América do Norte/epidemiologia , Sistema Solar , América do Sul/epidemiologia , Luz Solar , Adulto JovemRESUMO
It has been postulated that schizophrenia (SZ) is related to a lower expression of brain-derived neurotrophic factor (BDNF). In the past few years, an increasing number of divergent clinical studies assessing BDNF in serum and plasma have been published. It is now possible to verify the relationship between BDNF levels and severity of symptoms in SZ as well as the effects of antipsychotic drugs on BDNF using meta-analysis. The aims of this study were to verify if peripheral BDNF is decreased in SZ, whether its levels are correlated with positive and negative symptomatology and if BDNF levels change after antipsychotic treatment. This report consists of two distinct meta-analyses of peripheral BDNF in SZ including a total of 41 studies and more than 7000 participants: (1) peripheral BDNF levels in serum and plasma were moderately reduced in SZ compared with controls. Notably, this decrease was accentuated with the disease duration. However, the extent of peripheral BDNF level decrease did not correlate with the severity of positive and negative symptoms. (2) In plasma, but not serum, peripheral BDNF levels are consistently increased after antipsychotic treatment irrespective of the patient's response to medication. In conclusion, there is compelling evidence that there are decreased levels of peripheral BDNF in SZ, in parallel to previously described reduced cerebral BDNF expression. It remains unclear whether these systemic changes are causally related to the development of SZ or if they are merely a pathologic epiphenomenon.
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Antipsicóticos/uso terapêutico , Fator Neurotrófico Derivado do Encéfalo/sangue , Esquizofrenia/sangue , Esquizofrenia/tratamento farmacológico , Adulto , Biomarcadores/sangue , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
OBJECTIVE: We discuss the rationale behind staging systems described specifically for bipolar disorders. Current applications, future directions and research gaps in clinical staging models for bipolar disorders are outlined. METHOD: We reviewed the literature pertaining to bipolar disorders, focusing on the first episode onwards. We systematically searched data on staging models for bipolar disorders and allied studies that could inform the concept of staging. RESULTS: We report on several dimensions that are relevant to staging concepts in bipolar disorder. We consider whether staging offers a refinement to current diagnoses by reviewing clinical studies of treatment and functioning and the potential utility of neurocognitive, neuroimaging and peripheral biomarkers. CONCLUSION: Most studies to date indicate that globally defined late-stage patients have a worse overall prognosis and poorer response to standard treatment, consistent with patterns for end-stage medical disorders. We believe it is possible at this juncture to speak broadly of 'early'- and 'late'-stage bipolar disorder. Next steps require further collaborative efforts to consider the details of preillness onset and intermediary stages, and how many additional stages are optimal.
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Transtorno Bipolar/diagnóstico , Comitês Consultivos , Biomarcadores/sangue , Transtorno Bipolar/sangue , Progressão da Doença , Humanos , Índice de Gravidade de Doença , Sociedades MédicasRESUMO
INTRODUCTION: It is well established that patients with bipolar disorder experience functional impairment even in remission. Nevertheless, bipolar II disorder remains understudied because most investigations to date include only bipolar I patients or just a small sample of bipolar II patients, without explicitly comparing both subtypes of disorder. The main objective of the current report is to evaluate overall and multiple domains of functioning, specifically in bipolar II disorder compared to patients with bipolar I disorder and healthy subjects. METHODS: 233 subjects from 3 groups were compared: bipolar I patients (n=106), bipolar II patients (n=66) and healthy controls (n=61). Bipolar patients meeting criteria of remission were recruited at the Hospital Clinic of Barcelona and at different study sites in Argentina. All participants were assessed with 17-item Hamilton Depression Rating Scale (HAM-D), Young Mania Rating Scale (YMRS) and the Functioning Assessment Short Test (FAST). Clinical and sociodemographic data were also recorded. RESULTS: Both subgroups of patients, bipolar I and bipolar II, showed lower overall functioning (p<0.001) and in each domain of the FAST scale (all, p<0.001) when compared to the healthy control group. Tukey post hoc test revealed that bipolar II patients scored worse in the cognitive domain compared to bipolar I patients. However, after controlling for potential confounding variables, this difference disappeared and only older age (p<0.005) and HAM-D scores (p<0.001) remained significant. CONCLUSIONS: Our results suggest that bipolar II patients are as disabled as bipolar I patients. This may be explained, in part, because bipolar II patients experience greater lifetime residual depressive symptoms than the bipolar I subgroup, which may have particular impact on cognitive domains of functioning.