Seasonality and its distinct clinical correlates in bipolar II disorder

Seasonal patterns in Chinese population: Validating the seasonal pattern assessment questionnaire and exploring associations with psychiatric diagnoses and biological rhythms

Seasonal patterns (SP) exert a notable influence on the course and prognosis of patients with affective disorders, serving as a specifier in diagnosis. However, there is limited exploration of seasonality among psychotic patients, and the distinctions in seasonality among psychiatric patients remain unclear. In this study, we enrolled 198 psychiatric patients with anxiety and depressive disorders (A&D), bipolar disorder (BD), and schizophrenia (SZ), as well as healthy college students. Online questionnaires, including the Seasonal Pattern Assessment Questionnaire (SPAQ) for seasonality, the Morningness and Eveningness Questionnaire-5 (MEQ-5) for chronotypes, and the Pittsburgh Sleep Quality Index (PSQI), were administered. The validity and reliability of the Chinese version of the SPAQ were thoroughly analyzed, revealing a Cronbach's alpha of 0.896 with a two-factor structure. Results indicated that higher seasonality was correlated with poorer sleep quality and a more delayed chronotype (p < 0.05). Significant monthly variations were particularly evident in BD, specifically in mood, appetite, weight, social activities, and sleep dimensions (p < 0.001). In summary, the Chinese version of SPAQ is validated, demonstrating moderate correlations between seasonality, chronotype, and sleep quality. BD patients exhibited the strongest seasonality, while mood disorder patients displayed more delayed chronotypes than SZ.

Evening Chronotype and Suicide: Exploring Neuroinflammation and Psychopathological Dimensions as Possible Bridging Factors-A Narrative Review

A chronotype is generally defined as the variability of the phase angle of entrainment, while the latter reflects the relationship between the timing of a certain rhythm (e.g., the sleep-wake cycle) and the timing of an external temporal cue. Individuals can be placed on a spectrum from "morning types" (M types) to "evening types" (E types). E-chronotype has been proposed as a transdiagnostic risk factor for psychiatric conditions, and it has been associated with psychopathological dimensions. Eveningness seems to be correlated with both suicidal ideation (SI) and suicidal behavior (SB) through several possible mediating factors. Immunological alterations have also been linked to later chronotypes and SI/SB. This narrative review aims to summarize the evidence supporting the possible association between chronotypes and suicide and the eventual mediating role of neuroinflammation and several psychopathological dimensions. A search of the literature (2003-2023) was conducted using various databases: PUBMED, EMBASE, Scopus, UpToDate, PsycINFO, and Cochrane Library. English-language articles were collected and screened for eligibility. Despite the apparent absence of a direct correlation between E-chronotype and suicidality, E-chronotype promotes a chain of effects that could be involved in an increased risk of SB, in which with neuroinflammation possibly plays an intriguing role and some psychopathological dimensions may stand out.

Seasonality of brain function: role in psychiatric disorders

Seasonality patterns are reported in various psychiatric disorders. The current paper summarizes findings on brain adaptations associated with seasonal changes, factors that contribute to individual differences and their implications for psychiatric disorders. Changes in circadian rhythms are likely to prominently mediate these seasonal effects since light strongly entrains the internal clock modifying brain function. Inability of circadian rhythms to accommodate to seasonal changes might increase the risk for mood and behavior problems as well as worse clinical outcomes in psychiatric disorders. Understanding the mechanisms that account for inter-individual variations in seasonality is relevant to the development of individualized prevention and treatment for psychiatric disorders. Despite promising findings, seasonal effects are still understudied and only controlled as a covariate in most brain research. Rigorous neuroimaging studies with thoughtful experimental designs, powered sample sizes and high temporal resolution alongside deep characterization of the environment are needed to better understand the seasonal adaptions of the human brain as a function of age, sex, and geographic latitude and to investigate the mechanisms underlying the alterations in seasonal adaptation in psychiatric disorders.

Seasonal changes in mood and behavior contribute to suicidality and worthlessness in a population-based study

Limited evidence suggests that the seasonal changes in mood and behavior may associate with suicidality and the feelings of worthlessness, but these associations have not been analyzed in large population-based data. A random sample of adults (n = 4069), representative of the general population living in Finland, attended a nationwide health examination survey. Seasonal variations (seasonality) in mood and behavior were analyzed with the six items of global seasonality score (GSS) and the experienced problem due to these variations. Their impact on suicidality as well as on the feelings of worthlessness were analyzed using logistic regression models. After adjusting for age and gender, the GSS, each of its six items and the experienced problem due to the seasonal variations in mood and behavior all showed separately a significant association with suicidality as well as with worthlessness. After further adjustment for the education level and region of residence, the GSS, its mood item and the experienced problem remained significantly associated with both suicidality and worthlessness. Seasonal variations in mood and behavior have a significant association with both suicidality and worthlessness.

Enlightened: addressing circadian and seasonal changes in photoperiod in animal models of bipolar disorder

Bipolar disorders (BDs) exhibit high heritability and symptoms typically first occur during late adolescence or early adulthood. Affected individuals may experience alternating bouts of mania/hypomania and depression, with euthymic periods of varying lengths interspersed between these extremes of mood. Clinical research studies have consistently demonstrated that BD patients have disturbances in circadian and seasonal rhythms, even when they are free of symptoms. In addition, some BD patients display seasonal patterns in the occurrence of manic/hypomanic and depressive episodes as well as the time of year when symptoms initially occur. Finally, the age of onset of BD symptoms is strongly influenced by the distance one lives from the equator. With few exceptions, animal models useful in the study of BD have not capitalized on these clinical findings regarding seasonal patterns in BD to explore molecular mechanisms associated with the expression of mania- and depression-like behaviors in laboratory animals. In particular, animal models would be especially useful in studying how rates of change in photoperiod that occur during early spring and fall interact with risk genes to increase the occurrence of mania- and depression-like phenotypes, respectively. Another unanswered question relates to the ways in which seasonally relevant changes in photoperiod affect responses to acute and chronic stressors in animal models. Going forward, we suggest ways in which translational research with animal models of BD could be strengthened through carefully controlled manipulations of photoperiod to enhance our understanding of mechanisms underlying seasonal patterns of BD symptoms in humans. In addition, we emphasize the value of incorporating diurnal rodent species as more appropriate animal models to study the effects of seasonal changes in light on symptoms of depression and mania that are characteristic of BD in humans.

Rate of change in solar insolation is a hidden variable that influences seasonal alterations in bipolar disorder

The consensus in the literature is that bipolar disorder is seasonal. We argue that there is finer detail to seasonality and that changes in mood and energy in bipolar disorder are dictated by the rate of change of solar insolation.

Clinical correlates of seasonality in bipolar disorder: A specifier that needs specification?

OBJECTIVE

Seasonal pattern (SP) is a bipolar disorder (BD) specifier that indicates a tendency towards affective relapses during specific moments of the year. SP affects 15%-25% of BD patients. In the past, SP was applied only to depressive relapses while, in DSM-5, SP may be applied to both depressive and (hypo)manic episodes. We examined the association between different clinical correlates of BD and SP according to its current definition in a cohort of patients with BD type I (BDI) and II (BDII).

METHODS

Patients were recruited from a specialized unit and assessed according to the season of relapse and type of episode per season. SP and non-SP patients were compared looking into sociodemographic and clinical correlates. Significant variables at univariate comparisons were included in multivariate logistic regression with SP as the dependent variable.

RESULTS

708 patients were enrolled (503 BDI, 205 BDII), and 117 (16.5%) fulfilled DSM-5 criteria for SP. The mean age was 45.3 years (SD = 14.18), and 389 were female (54.9%). The logistic regression model included a significant contribution of BDII (OR = 2.23, CI 1.4-3.55), family history of mood disorder (OR = 1.97, CI 1.29-3.01), undetermined predominant polarity (OR = 0.44, CI 0.28-0.70), and aggressive behavior (OR = 0.42, CI 0.23-0.75).

CONCLUSION

Our results outline a novel positive association of SP with undetermined predominant polarity, BDII, family history of mood disorder, and with fewer aggressiveness-related symptoms. Seasonality is associated with a biphasic pattern with similar dominance of (hypo)mania and depression and is more frequent in BDII as compared to BDI. Seasonal episodes may be easier to predict, but difficult to prevent.

Sensitivity to Climate and Weather Changes in Euthymic Bipolar Subjects: Association With Suicide Attempts

BACKGROUND

Climate and weather are known to affect multiple areas of human life, including mental health. In bipolar disorder (BD), seasonality represents an environmental trigger for mood switches, and climatic variables may contribute to recurrences. Several studies reported seasonal and climatic-related variations in the rate of suicide attempts. Suicide risk is relevant in BD, with approximately 25% of patients attempting suicide. Therefore, this study aimed to assess sensitivity to weather and climatic variations in BD subjects and its relationship with lifetime suicide attempts.

METHODS

Three hundred fifty-two euthymic BD and 352 healthy control subjects, homogeneous with respect to socio-demographic characteristics, were enrolled. All participants were administered the METEO-Questionnaire (METEO-Q) to evaluate susceptibility to weather and climatic changes. We also investigated the potential relationship between sensitivity to climate and weather and lifetime suicide attempts in BD patients.

RESULTS

METEO-Q scores and the number of subjects reaching the cut-off for meteorosensitivity/meteoropathy were significantly higher in BD patients. Within the clinical group, BD subjects with lifetime suicide attempts obtained higher METEO-Q scores, with no differences between BD-I and BD-II. The number of suicide attempts directly correlated with METEO-Q scores. The presence of suicide attempts was associated with the physical and psychological symptoms related to weather variations.

DISCUSSION

Our findings support the relevance of sensitivity to weather and climate variations in a large sample of BD subjects and point out the association of this feature with lifetime suicide attempts.

Psychopathologic structure of bipolar disorders: exploring dimensional phenotypes, their relationships, and their associations with bipolar I and II disorders

BACKGROUND

Given its diverse disease courses and symptom presentations, multiple phenotype dimensions with different biological underpinnings are expected with bipolar disorders (BPs). In this study, we aimed to identify lifetime BP psychopathology dimensions. We also explored the differing associations with bipolar I (BP-I) and bipolar II (BP-II) disorders.

METHODS

We included a total of 307 subjects with BPs in the analysis. For the factor analysis, we chose six variables related to clinical courses, 29 indicators covering lifetime symptoms of mood episodes, and 6 specific comorbid conditions. To determine the relationships among the identified phenotypic dimensions and their effects on differentiating BP subtypes, we applied structural equation modeling.

RESULTS

We selected a six-factor solution through scree plot, Velicer's minimum average partial test, and face validity evaluations; the six factors were cyclicity, depression, atypical vegetative symptoms, elation, psychotic/irritable mania, and comorbidity. In the path analysis, five factors excluding atypical vegetative symptoms were associated with one another. Cyclicity, depression, and comorbidity had positive associations, and they correlated negatively with psychotic/irritable mania; elation showed positive correlations with cyclicity and psychotic/irritable mania. Depression, cyclicity, and comorbidity were stronger in BP-II than in BP-I, and they contributed significantly to the distinction between the two disorders.

CONCLUSIONS

We identified six phenotype dimensions; in addition to symptom features of manic and depressive episodes, various comorbidities and high cyclicity constructed separate dimensions. Except for atypical vegetative symptoms, all factors showed a complex interdependency and played roles in discriminating BP-II from BP-I.

The relationship of person-specific eveningness chronotype, greater seasonality, and less rhythmicity to suicidal behavior: A literature review

BACKGROUND

Epidemiological data have demonstrated seasonal and circadian patterns of suicidal deaths. Several reviews and meta-analyses have confirmed the relationship between sleep disturbance and suicidality. However, these reviews/meta-analyses have not focused on seasonal and circadian dysfunction in relation to suicidality, despite the common presence of this dysfunction in patients with mood disorders. Thus, the current literature review analyzed studies investigating person-specific chronotype, seasonality, and rhythmicity in relation to suicidal thoughts and behaviors.

METHODS

Study authors reviewed articles related to individual-level chronotype, seasonality, and rhythmicity and suicidality that were written in English and not case reports or reviews.

RESULTS

This review supports a relationship between an eveningness chronotype, greater seasonality, and decreased rhythmicity with suicidal thoughts and behaviors in those with unipolar depression, as well as in other psychiatric disorders and in children/adolescents.

LIMITATIONS

These findings need to be explored more fully in mood disordered populations and other psychiatric populations, in both adults and children, with objective measurement such as actigraphy, and with chronotype, seasonality, and rhythmicity as well as broader sleep disturbance measurement all included so the construct(s) most strongly linked to suicidality can be best identified.

CONCLUSIONS

Eveningness, greater seasonality, and less rhythmicity should be considered in individuals who may be at risk for suicidal thoughts and behaviors and may be helpful in further tailoring assessment and treatment to improve patient outcome.

Bipolar disorder in Asia: Illness course and contributing factors

BACKGROUND

Epidemiological studies analysing the course of Bipolar Disorder (BD) are relatively rare in the Asian context, contributing to the uncertainty regarding the prevalent course patterns and factors influencing such patterns. The current review identifies the regional characteristics of BD course patterns and the associated factors.

METHODS

A review of the existing literature was done using 'PubMed' and 'Cochrane' databases which yielded 145 studies including those from all 48 Asian countries. Relevant discussions from the Western literature were incorporated.

RESULTS

Regional and cross-national studies reveal a mania-predominant course in BD in Asian countries. Prolonged depressive episodes and comorbid anxiety disorders worsen the course of BD-II. Certain risk factors such as the young age of onset and greater episode frequency are useful predictors of bipolar diatheses. Substance use disorder comorbidity is more prevalent in males whereas depression and suicidal behaviours are more frequent in females with BD. Comorbid anxiety and personality disorders also encumber the illness course. Logistic reasons and ignorance of side-effects were specifically associated with poor adherence. An 'eveningness' chronotype and poor sleep quality were associated with frequent recurrences. Seasonal patterns vary among men and women, especially for depressive episodes.

LIMITATIONS

The effects of treatment and childhood BD course features were not discussed.

CONCLUSIONS

There are region-specific characteristics in bipolar illness course and factors influencing such course patterns compared to the rest of the World. Future research from Asia shall attempt to study the neurobiological underpinnings of such characteristics and plan appropriate strategies to address the same.

Association between the zinc finger protein 804A (ZNF804A) gene and the risk of schizophrenia and bipolar I disorder across diagnostic boundaries

OBJECTIVES

In this study, we aimed to determine the role of genetic variations within the zinc finger protein 804A (ZNF804A) gene, a candidate for a psychosis risk-conferring gene, in the development of schizophrenia (SZ) and bipolar disorder (BP) in the Korean population.

METHODS

A total of 921 patients with SZ, bipolar I (BP-I) and II (BP-II) disorder, and 502 control subjects participated in the study. Twenty-one tag single nucleotide polymorphisms (SNPs) across the genomic region of ZNF804A and seven reference SNPs based on previous reports were genotyped. We applied logistic regression analyses under additive, dominant and recessive models.

RESULTS

Fifteen of the 28 SNPs showed a nominally significant association with at least one diagnostic group. However, none of these associations remained significant after false discovery rate (FDR) correction. As the trend of association was observed mostly in SZ and BP-I with similar patterns, we performed a post hoc analysis for the combined SZ and BP-I group. Five SNPs (rs2369595, rs6755404, rs10931156, rs12476147 and rs1366842) showed a significant association with an FDR-corrected P of <.05.

CONCLUSIONS

This study supports a possible role of ZNF804A in the common susceptibility of major psychoses, and identified additional candidate variants of the gene in the Korean population.

Seasonal pattern in bipolar disorders and cardio-vascular risk factors: A study from the FACE-BD cohort

Seasonal pattern (SP) and metabolic syndrome (MetS) are major contributors to poor outcome in bipolar disorders (BD). Patients with seasonal bipolar depression present increased appetite, carbohydrate cravings, weight gain, and hypersomnia, which can increase the development of MetS. MetS also appears to be associated with seasonal mood changes in the general population. This study examines whether a SP in BD is associated with an increased risk of MetS and its sub-components. One thousand four hundred and seventy-one outpatients with BD were systematically enrolled from 2009 to 2016. Inclusion required a disease duration of at least 5 years, with 486 (33%) patients with SP (SP+) and 985 (67%) without (SP-) according to the DSM IV-TR criteria. When using continuous measures of metabolic components, SP+ patients, as compared to SP-, suffered from higher levels for systolic blood pressure (p = 0.01), low-density lipoprotein cholesterol (p = 0.009), fasting glucose (p = 0.007), triglycerides levels (p = 0.03), a larger abdominal circumference (p = 0.02), and a higher body mass index (p = 0.07). In the covariance analysis, adjusted for gender, age, and bipolar subtype, as well as the number of depressive and hypomanic episode, SP+ patients had a significantly higher level of fasting glucose and higher systolic blood pressure. The frequency of MetS did not differ between groups (21.2% in SP- versus 23.9% in SP+). When using categorical definitions for abnormal metabolic components (International Diabetes Federation criteria), there were no differences between groups, except that SP+ patients were more overweight/obese as compared to SP- patients (55.03% versus 46.7%, respectively; p = 0.002) and tended to have more frequently high fasting glucose (18.2% versus 14.3%, respectively; p = 0.07). MetS was frequent in patients with BD, however not associated with SP. Patients with SP appeared more vulnerable to overweight/obesity and presented with higher levels of MetS subcomponents although these parameters were mainly in the normal range. All patients with BD should benefit from early screening and targeted management of cardio-vascular risk factors.

Solar radiation increases suicide rate after adjusting for other climate factors in South Korea

OBJECTIVE

Previous studies have indicated that suicide rates have significant seasonal variations. There is seasonal discordance between temperature and solar radiation due to the monsoon season in South Korea. We investigated the seasonality of suicide and assessed its association with climate variables in South Korea.

METHOD

Suicide rates were obtained from the National Statistical Office of South Korea, and climatic data were obtained from the Korea Meteorological Administration for the period of 1992-2010. We conducted analyses using a generalized additive model (GAM). First, we explored the seasonality of suicide and climate variables such as mean temperature, daily temperature range, solar radiation, and relative humidity. Next, we identified confounding climate variables associated with suicide rate. To estimate the adjusted effect of solar radiation on the suicide rate, we investigated the confounding variables using a multivariable GAM.

RESULTS

Suicide rate showed seasonality with a pattern similar to that of solar radiation. We found that the suicide rate increased 1.008 times when solar radiation increased by 1 MJ/m² after adjusting for other confounding climate factors (P < 0.001).

CONCLUSION

Solar radiation has a significant linear relationship with suicide after adjusting for region, other climate variables, and time trends.

Tracking search engine queries for suicide in the United Kingdom, 2004-2013

OBJECTIVES

First, to determine if a cyclical trend is observed for search activity of suicide and three common suicide risk factors in the United Kingdom: depression, unemployment, and marital strain. Second, to test the validity of suicide search data as a potential marker of suicide risk by evaluating whether web searches for suicide associate with suicide rates among those of different ages and genders in the United Kingdom.

STUDY DESIGN

Cross-sectional.

METHODS

Search engine data was obtained from Google Trends, a publicly available repository of information of trends and patterns of user searches on Google. The following phrases were entered into Google Trends to analyse relative search volume for suicide, depression, job loss, and divorce, respectively: 'suicide'; 'depression + depressed + hopeless'; 'unemployed + lost job'; 'divorce'. Spearman's rank correlation coefficient was employed to test bivariate associations between suicide search activity and official suicide rates from the Office of National Statistics (ONS).

RESULTS

Cyclical trends were observed in search activity for suicide and depression-related search activity, with peaks in autumn and winter months, and a trough in summer months. A positive, non-significant association was found between suicide-related search activity and suicide rates in the general working-age population (15-64 years) (ρ = 0.164; P = 0.652). This association is stronger in younger age groups, particularly for those 25-34 years of age (ρ = 0.848; P = 0.002).

CONCLUSIONS

We give credence to a link between search activity for suicide and suicide rates in the United Kingdom from 2004 to 2013 for high risk sub-populations (i.e. male youth and young professionals). There remains a need for further research on how Google Trends can be used in other areas of disease surveillance and for work to provide greater geographical precision, as well as research on ways of mitigating the risk of internet use leading to suicide ideation in youth.

Suicide attempts in bipolar disorders: comprehensive review of 101 reports

OBJECTIVE

Assess reported risk of suicide attempts by patients with bipolar disorder (BD).

METHOD

Systematic searching yielded 101 reports from 22 countries (79 937 subjects). We analyzed for risk (%) and incidence rates (%/year) of attempts, comparing sex and diagnostic types, including by meta-analysis.

RESULTS

Attempt risk averaged 31.1% [CI: 27.9-34.3] of subjects, or 4.24 [3.78-4.70]%/year. In BD-I (43 studies) and BD-II subjects (30 studies), risks (29.9%, 31.4%) and incidence rates (4.01, 4.11%/year) were similar and not different by meta-analysis. Among women vs. men, risks (33.7% vs. 25.5%) and incidence (4.50 vs. 3.21%/year) were greater (also supported by meta-analysis: RR = 1.35 [CI: 1.25-1.45], P < 0.0001). Neither measure was related to reporting year, % women/study, or to onset or current age. Risks were greater with longer exposure, whereas incidence rates decreased with longer time at risk, possibly through 'dilution' by longer exposure.

CONCLUSION

This systematic update of international experience underscores high risks of suicide attempts among patients with BD (BD-I = BD-II; women > men). Future studies should routinely include exposure times and incidence rates by diagnostic type and sex for those who attempt suicide or not.