Birth-cohort and dual diagnosis effects on age-at-onset in Brazilian patients with bipolar I disorder

Influence of birth cohort on age of onset cluster analysis in bipolar I disorder

Purpose:

Two common approaches to identify subgroups of patients with bipolar disorder are clustering methodology (mixture analysis) based on the age of onset, and a birth cohort analysis. This study investigates if a birth cohort effect will influence the results of clustering on the age of onset, using a large, international database.

Methods:

The database includes 4037 patients with a diagnosis of bipolar I disorder, previously collected at 36 collection sites in 23 countries. Generalized estimating equations (GEE) were used to adjust the data for country median age, and in some models, birth cohort. Model-based clustering (mixture analysis) was then performed on the age of onset data using the residuals. Clinical variables in subgroups were compared.

Results:

There was a strong birth cohort effect. Without adjusting for the birth cohort, three subgroups were found by clustering. After adjusting for the birth cohort or when considering only those born after 1959, two subgroups were found. With results of either two or three subgroups, the youngest subgroup was more likely to have a family history of mood disorders and a first episode with depressed polarity. However, without adjusting for birth cohort (three subgroups), family history and polarity of the first episode could not be distinguished between the middle and oldest subgroups.

Conclusion:

These results using international data confirm prior findings using single country data, that there are subgroups of bipolar I disorder based on the age of onset, and that there is a birth cohort effect. Including the birth cohort adjustment altered the number and characteristics of subgroups detected when clustering by age of onset. Further investigation is needed to determine if combining both approaches will identify subgroups that are more useful for research.

Secular trends in the age at onset of bipolar I disorder - Support for birth cohort effects from interational, multi-centre clinical observational studies

OBJECTIVE

To examine any association of birth decade, sex and exposure to alcohol and/or substance use disorders (ASUD) with age at onset (AAO) of bipolar I disorder (BD-I).

METHODS

Using data from a representative clinical sample of 3896 BD-I cases recruited from 14 European countries, we examined AAO distributions in individuals born in consecutive birth decades. Cumulative probabilities with Mantel-Cox log-rank tests, pairwise comparisons and Odds Ratios (OR) with 95% confidence intervals (95% CI) were employed to analyze AAO according to birth decade, sex, and presence or absence of an ASUD.

RESULTS

In the total sample, median AAO of BD-I decreased from about 41 years for those born in the 1930s to about 26 years for those born in the 1960s. In a sub-sample of 1247 individuals (selected to minimize confounding), AAO significantly decreased for males and females born in each consecutive decade between 1930 and 50 (OR: 0.65; 95% CI: 0.51, 0.81), and for cases with an ASUD as compared to without (OR: 0.77, 95% CI: 0.69, 0.87). The best fitting regression model identified an independent effect for each birth decade and an interaction between ASUD status and sex, with a consistently earlier AAO in males with an ASUD (OR: 0.79: 95% CI: 0.70, 0.91).

CONCLUSIONS

In BD-I cases diagnosed according to internationally recognized criteria and recruited to pan-European clinical observational studies, the AAO distributions are compatible with a birth cohort effect. A potentially modifiable risk factor, namely ASUD status, was associated with the observed reduction in AAO, especially in males.

Solar insolation in springtime influences age of onset of bipolar I disorder

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.

Is age of onset associated with severity, prognosis, and clinical features in bipolar disorder? A meta-analytic review

OBJECTIVES

To identify clinical characteristics and adverse outcomes associated with an earlier age of onset of bipolar disorder.

METHODS

A comprehensive search yielded 15 empirical papers comparing clinical presentation and outcomes in individuals with bipolar disorder grouped according to age of onset (total N=7370). The following variables were examined to determine odds ratios (ORs) and 95% confidence intervals (CIs): presence of Axis I comorbidity, rapid cycling, psychotic symptoms, mixed episodes (DSM-IV), lifetime suicide attempts, lifetime alcohol and substance abuse, symptom severity, and treatment delay.

RESULTS

Early age of onset was found to be associated with longer delay to treatment (Hedges' g=0.39, P=.001), greater severity of depression (Hedges' g=0.42, P<.001), and higher levels of comorbid anxiety (OR=2.34, P<.001) and substance use (OR=1.80, P<.001). Surprisingly, no association was found between early age of onset and clinical characteristics such as psychotic symptoms or mixed episodes as defined by DSM-IV.

CONCLUSIONS

Earlier age of onset of bipolar disorder is associated with factors that can negatively impact long-term outcomes such as increased comorbidity. However, no association was found between early onset and indicators of severity or treatment resistance such as psychotic symptoms. Clinical features found to have the strongest relationship with early age of onset were those potentially amenable to pharmacological and psychological treatment. Results highlight the importance of early identification and provide potential areas of focus for the development of early intervention in bipolar disorder.

Using admixture analysis to examine birth-cohort effects on age at onset of bipolar disorder

OBJECTIVE

It is suggested that age at onset (AAO) of bipolar I disorder (BP-I) is decreasing. We tested for a birth-cohort effect on AAO using admixture analysis.

METHOD

A clinical sample of 3896 BP-I cases was analysed using two approaches: (i) in a subsample with untruncated AAO × birth year distribution (n = 1865), we compared the best-fitting model for the observed AAO in patients born ≤1960 and >1960, (ii) to control for potential confounders, two separate subsamples born ≤1960 and >1960 were matched for age at interview (n = 250), and a further admixture analysis was undertaken.

RESULTS

The two approaches indicated that the proportion of cases in the early AAO category was significantly greater in cases born >1960; manic onsets were also more frequent in the early onset BP-I cases born >1960.

CONCLUSION

The decrease in AAO of BP-I in recent birth-cohorts appears to be associated with an increase in the proportion of cases in the early onset subgroup; not with a decrease in the mean AAO in each putative subgroup. This could indicate temporal changes in exposure to risk factors for mania.

Cannabis use disorder is associated with greater illness severity in tobacco smoking patients with bipolar disorder

OBJECTIVE

Cannabis use disorders (CUD) may influence the course of bipolar disorder (BD), but key confounding factors such as tobacco smoking have not been adequately addressed. This study examined whether CUD was associated with a more severe illness course in tobacco smoking BD patients.

METHODS

A sample of French and Norwegian tobacco smoking patients with BD I and II (N=642) was investigated. DSM-IV diagnoses and other characteristics were obtained through personal interviews using structured questionnaires. The association between CUD and illness course was assessed in regression analyses.

RESULTS

In bivariate analyses, CUD was associated with earlier BD onset, higher frequency of manic (in BD I) and depressive episodes and hospitalizations per illness year, and a higher occurrence of psychotic episodes. After controlling for potential confounders, the relationships with earlier BD onset (B=-5.60 95% CI=-7.65 to -3.64), and increased rates of manic episodes (OR=1.93, 95% CI: 1.15 to 3.23) and hospitalizations (OR=2.93, 95% CI: 1.85 to 4.64) remained statistically significant.

LIMITATIONS

Despite the multivariate approach, differences between the two samples may lead to spurious findings related to hidden confounders. Substance use and mood episode information was collected retrospectively, and potential birth cohort effects could not be controlled for.

CONCLUSION

Studies have found associations between tobacco smoking and poorer outcomes in BD. In this study on tobacco smoking BD patients we report an association between CUD and illness severity, suggesting that CUD exacerbates the disease evolution independently of tobacco smoking. Specific treatment and prevention programs addressing CUD in BD patients are warranted.

Bipolar patients referred to specialized services of care: Not resistant but impaired by sub-syndromal symptoms. Results from the FACE-BD cohort

OBJECTIVE

A national network of expert centers for bipolar disorders was set up in France to provide support, mainly for psychiatrists, who need help for managing bipolar disorder patients. The aims of this article are to present the main characteristics of the patients referred to an expert center in order to highlight the major disturbances affecting these patients and to understand the most significant difficulties encountered by practitioners dealing with bipolar disorder patients.

METHODS

Patients were evaluated by trained psychiatrists and psychologists, with standardized and systematic assessment using interviews and self-report questionnaires.

RESULTS

All patients (n = 839) met Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition criteria for bipolar disorder I (48.4%), bipolar disorder II (38.1%) or bipolar disorder-not otherwise specified (13.5%). Mean illness duration was 17 years (±11.3), with 41.9% of patients having a history of suicide attempts. Lifetime comorbidities were 43.8% for anxiety disorders and 32.8% for substance abuse. At the point of inclusion, most patients (76.2%) were not in an acute phase, being considered to have a syndromal remission, but which still required referral to a tertiary system of care. Among these patients, 37.5% had mild to moderate residual depressive symptoms (Montgomery and Asberg Depression Rating Scale ranging from 7 to 19) despite 39% receiving an antidepressant. However, 47.8% were considered to be poorly adherent to medication; 55% showed evidence of sleep disturbances, with half being overweight; 68.1% of patients showed poor functioning (Functioning Assessment Short Test ⩾ 12) with this being linked to residual depressive symptoms, sleep disturbances and increased body mass index.

CONCLUSIONS

It appears that bipolar disorder patients referred to an expert center in most cases do not suffer from a severe or resistant illness but they rather have residual symptoms, including subtle but chronic perturbations that have a major impact on levels of functioning. The longitudinal follow-up of these patients will enable a better understanding of the evolution of such residual symptoms.

Mortality and secular trend in the incidence of bipolar disorder

BACKGROUND

The world-wide interest in bipolar disorder is illustrated by an exponential increase in publications on the disorder registered in Pubmed since 1990. This inspired an investigation of the epidemiology of bipolar disorder.

METHODS

This was a register-based cohort study. All first-ever diagnoses of bipolar disorder (International Classification of Diseases-10: F31) were identified in the nationwide Danish Psychiatric Central Research Register between 1995 and 2012. Causes of death were obtained from The Danish Register of Causes of Death. Age- and gender standardized incidence rates, standardized mortality ratio (SMR) and Kaplan-Meier survival estimates were calculated.

RESULTS

We identified 15,334 incident cases of bipolar disorder. The incidence rate increased from 18.5/100,000 person-years (PY) in 1995 to 28.4/100,000 PY in 2012. The mean age at time of diagnosis decreased significantly from 54.5 years in 1995 to 42.4 years in 2012 (p<0.001). The mean time from first affective diagnosis to diagnosis of bipolar disorder was 7.9 years (SD 9.1). The SMR was 1.7 (95%-CI 1.2-2.1). Causes of death were mainly natural; 9% died from suicide.

LIMITATIONS

Only patients in psychiatric care were included. The outpatient registry opened in 1995. Patients treated solely in outpatient units are not recorded previously. Systematic studies validating all the clinical diagnoses of the registry do not exist.

CONCLUSIONS

The incidence of bipolar disorder has increased in the last 10 years. The SMR was significantly increased. Half of the patients were known to have another affective disorder. This should be considered in future decisions regarding the healthcare organization.

Cannabis use and first manic episode

BACKGROUND

Cannabis is the most commonly abused drug among patients with bipolar disorder. Available data has shown that the risk of psychotic disorders increases with the frequency and intensity of cannabis abuse. The present purpose was to review relevant studies to investigate whether cannabis use can be linked to the onset of mania in bipolar disorder.

METHODS

Articles published between 1972 and December 2013 were searched on Medline and PsychInfo using the following keywords: first manic episode, or onset mania, or bipolar disorder and cannabis. Relevant papers cited in the references of selected articles were further considered for inclusion into the review.

RESULTS

Lifetime use of cannabis among bipolar patients appears to be around 70% and approximately 30% of patients with a bipolar disorder present a comorbidity of cannabis abuse or dependence. Cannabis use is associated with younger age at onset of first mania and with more frequent depressive or manic episodes, although the evidence is somewhat inconsistent. Likewise cannabis consumption is related to poorer outcome and an increased risk of rapid cycling or mixed episodes. In contrast, neuro-cognitive functioning seems to be positively affected in patients with psychiatric comorbidity. While cannabis use often precedes first manic episodes, the causal direction remains to be determined.

LIMITATIONS

Variations in definition of cannabis use/dependence. Lack of controlled studies limiting definite conclusions about a putative causal relationship between cannabis and onset of mania.

CONCLUSIONS

Further investigations are needed to clarify the relationships between cannabis use and first manic episode.

Age at onset in bipolar I affective disorder in the USA and Europe

OBJECTIVE

To test for differences in reported age at onset (AAO) of bipolar I affective disorder in clinical samples drawn from Europe and the USA.

METHODS

Admixture analysis was used to identify the model best fitting the observed AAO distributions of two large samples of bipolar I patients from Europe and USA (n = 3616 and n = 2275, respectively). Theoretical AAO functions were compared between the two samples.

RESULTS

The model best fitting the observed distribution of AAO in both samples was a mixture of three Gaussian distributions. The theoretical AAO functions of bipolar I disorder differed significantly between the European and USA populations, with further analyses indicating that (i) the proportion of patients belonging to the early-onset subgroup was higher in the USA sample (63 vs. 25%) and (ii) mean age at onset (±SD) in the early-onset subgroup was lower for the USA sample (14.5 ± 4.9 vs. 19 ± 2.7 years).

CONCLUSIONS

The models best describing the reported AAO distributions of European and USA bipolar I patients were remarkably stable. The intermediate- and late-onset subgroups had similar characteristics in the two samples. However, the theoretical AAO function differed significantly between the USA and European samples due to the higher proportion of patients in the early-onset subgroup and the lower mean age-at-onset in the USA sample.

The influence of psychoeducation on regulating biological rhythm in a sample of patients with bipolar II disorder: a randomized clinical trial

Introduction

Changes in biological rhythm are among the various characteristics of bipolar disorder, and have long been associated with the functional impairment of the disease. There are only a few viable options of psychosocial interventions that deal with this specific topic; one of them is psychoeducation, a model that, although it has been used by practitioners for some time, only recently have studies shown its efficacy in clinical practice.

Aim

To assess if patients undergoing psychosocial intervention in addition to a pharmacological treatment have better regulation of their biological rhythm than those only using medication.

Method

This study is a randomized clinical trial that compares a standard medication intervention to an intervention combined with drugs and psychoeducation. The evaluation of the biological rhythm was made using the Biological Rhythm Interview of Assessment in Neuropsychiatry, an 18-item scale divided in four areas (sleep, activity, social rhythm, and eating pattern). The combined intervention consisted of medication and a short-term psychoeducation model summarized in a protocol of six individual sessions of 1 hour each.

Results

The sample consisted of 61 patients with bipolar II disorder, but during the study, there were 14 losses to follow-up. Therefore, the final sample consisted of 45 individuals (26 for standard intervention and 19 for combined). The results showed that, in this sample and time period evaluated, the combined treatment of medication and psychoeducation had no statistically significant impact on the regulation of biological rhythm when compared to standard pharmacological treatment.

Conclusion

Although the changes in biological rhythm were not statistically significant during the time period evaluated in this study, it is noteworthy that the trajectory of the score showed a trend towards improvement, which may indicate a positive impact on treatment, though it may take a longer time than expected.

Early functional impairment in bipolar youth: a nested population-based case-control study

OBJECTIVES

The objective of this report is to evaluate functioning in bipolar disorder in a population-based sample of young adults (18 to 24 years old). To this end, people with bipolar disorder were compared with matched participants with only depressive episodes and control subjects without a history of mood episodes.

METHODS

Case-control study nested in a population-based sample. Caseness was confirmed with the Structured Clinical Interview for DSM-IV. The Functioning Assessment Short Test was used as a measure of general functioning. A multivariate model was elaborated to account for potential confounders.

RESULTS

The sample consisted of 231 subjects. Both bipolar disorder (coef=0.60, SE=0.14, p<0.001) and major depression (coef=0.44, SE=0.14, p=0.001) were associated with functioning in the multivariate model. Current depressive symptoms appeared to influence functioning in those with major depression (Z=2.05, p=0.04), but not in those with bipolar disorder (Z=0.78, p=0.43).

LIMITATION

Neuropsychological testing was not performed and we see it as an important limitation of this study.

CONCLUSION

This population-based study further reinforces the notion that functional impairment is a fundamental characteristic of bipolar illness. It is present from early stages and is not completely explained by mood symptoms.

[Age at Onset as a Marker of Subtypes of Manic-Depressive Illness]

INTRODUCTION

Age at onset of bipolar disorder has been reported as a variable that may be associated with different clinical subtypes.

OBJECTIVE

To identify patterns in the distributions of age at onset of bipolar disease and to determine whether age at onset is associated with specific clinical characteristics.

METHODS

Admixture analysis was applied to identify bipolar disorder subtypes according to age at onset. The EMUN scale was used to evaluate clinical characteristics and principal components were estimated to evaluate the relationship between subtypes according to age at onset and symptoms in the acute in the acute phase, using multivariable analyses.

RESULTS

According to age at onset, three distributions have been found: early onset: 17.7 years (S.D. 2.4); intermediate-onset: 23.9 years (S.D. 5.6); late onset: 42.8 years (S.D. 12.1). The late-onset group is antisocial, with depressive symptoms, thinking and language disorders, and socially disruptive behaviors.

CONCLUSIONS

In patients having bipolar disorder, age at onset is antisocial with three groups having specific clinical characteristics.

Prevalence of episodes of mania and hypomania and associated comorbidities among young adults

OBJECTIVE

To evaluate the prevalence of episodes of mania and hypomania, as well as associated factors and comorbidities among adults 18 to 24 years old in the city of Pelotas, Brazil.

METHOD

This is a cross-sectional population-based study. The sample was selected through conglomerates, and episodes of mania and hypomania were assessed using the Mini International Neuropsychiatric.

RESULTS

The sample consisted of 1560 subjects. The lifetime prevalence of manic and hypomanic episodes was 7.5% and 5.3%, respectively. Subjects with (hypo)manic episodes had a higher prevalence of anxiety disorders, substance abuse and suicidality.

LIMITATION

The high rate of (hypo)mania may to some extent reflect diagnostic error.

CONCLUSION

Such high prevalence of (hypo)mania may nonetheless be valid as it was associated with corresponding rates of comorbidity and suicidality.

Comorbidades clínicas e psiquiátricas em pacientes com transtorno bipolar do tipo I

Contexto: O transtorno bipolar tipo I está comumente associado a comorbidades clínicas e psiquiátricas, mas ainda há poucos dados disponíveis sobre pacientes brasileiros. Objetivos: O objetivo do presente estudo foi avaliar a prevalência de comorbidades clínicas e psiquiátricas em uma amostra brasileira de pacientes bipolares tipo I. O objetivo secundário foi investigar as associações de características clínico-demográficas e comorbidades com tentativas de suicídio. Métodos: Foram incluídos neste estudo 94 pacientes bipolares tipo I. O diagnóstico psiquiátrico foi determinado utilizando-se a avaliação Mini International Neuropsychiatric Interview (MINI-Plus). O diagnóstico de comorbidades clínicas foi baseado na história clínica e no acompanhamento de clínicos gerais. Resultados: As comorbidades mais prevalentes nos pacientes bipolares foram: transtorno de ansiedade generalizada (19,20%), dependência de substâncias (43,60%), hipertensão arterial (29,80%), diabetes mellitus (17,00%), dislipidemia (22,30%) e hipotireoidismo (19,10%). Não foram encontradas diferenças estatísticas em relação às características demográficas ou à prevalência de comorbidades nos grupos com e sem tentativa de suicídio. Conclusão: Pacientes bipolares atendidos em serviço psiquiátrico apresentam elevada prevalência de comorbidades psiquiátricas e clínicas. Nessa população, tentativas de suicídio não se associam com a presença de comorbidades ou características demográficas.