Low anxiety disorder comorbidity rate in bipolar disorders in Han Chinese in Taiwan

Effects of mood episodes and comorbid anxiety on neuropsychological impairment in patients with bipolar spectrum disorder

OBJECTIVES

Cases of patients with bipolar disorder (BD) having neuropsychological impairment have been reported, although inconsistently. The possibility of comorbidity with anxiety disorder (AD) has been suggested. The association between mood episodes and AD comorbidity on neuropsychological performance is unclear and thus was investigated in the current study.

METHODS

All participants were informed about and agreed to participate in this study. Patients with BD were recruited from outpatient and inpatient settings, and healthy controls (HCs) were recruited as a comparison group. Six hundred and twenty-eight participants (175 HCs and 453 BD-56 BDI and 397 BDII) were studied based on their current mood episode, namely, depressive (BD_d ), manic/hypomanic (BDm), mixed (BDmix), and euthymic (BDeu), compared with/without AD comorbidity (164 with AD).

RESULTS

Compared to HCs, all BD groups had significantly more impaired neuropsychological profiles, but the BDeu group was found to have less impairment in memory and executive function than the episodic BD groups. The percentage of AD comorbidity in BDd, BDm, BDmix, and BDeu was 33.9%, 40.3%, 33.0%, and 35.6%, respectively (χ²  = 1.61, p > .05). The results show that AD plays a different role in neuropsychological impairment across various mood episodes in BD.

CONCLUSION

Memory impairment and executive dysfunction may be state-like cognitive phenotypes and are affected by AD comorbidity during mixed and depressive episodes in BD, while sustained attention deficiencies are more like trait markers, regardless of mood episodes, and persist beyond the course of the illness. The AD comorbidity effect on attentional deficit is greater when suffering from a manic episode.

Role of DRD2 and ALDH2 genes in bipolar II disorder with and without comorbid anxiety disorder

The presence of comorbid anxiety disorders (AD) and bipolar II disorders (BP-II) compounds disability complicates treatment, worsens prognosis, and has been understudied. The genes involved in metabolizing dopamine and encoding dopamine receptors, such as aldehyde dehydrogenase 2 (ALDH2) and dopamine D2 receptor (DRD2) genes, may be important to the pathogenesis of BP-II comorbid with AD. We aimed to clarify ALDH2 and DRD2 genes for predisposition to BP-II comorbid with and without AD. The sample consisted of 335 subjects BP-II without AD, 127 subjects BP-II with AD and 348 healthy subjects as normal control. The genotypes of the ALDH2 and DRD2 Taq-IA polymorphisms were determined using polymerase chain reactions plus restriction fragment length polymorphism analysis. Logistic regression analysis showed a statistically significant association between DRD2 Taq-I A1/A2 genotype and BP-II with AD (OR = 2.231, P = 0.021). Moreover, a significant interaction of the DRD2 Taq-I A1/A1 and the ALDH2*1*1 genotypes in BP-II without AD was revealed (OR = 5.623, P = 0.001) compared with normal control. Our findings support the hypothesis that a unique genetic distinction between BP-II with and without AD, and suggest a novel association between DRD2 Taq-I A1/A2 genotype and BP-II with AD. Our study also provides further evidence that the ALDH2 and DRD2 genes interact in BP-II, particularly BP-II without AD.

Comorbidity of bipolar and anxiety disorders: An overview of trends in research

Over the last three decades burgeoning research has shown that anxiety disorder comorbidity is not only highly prevalent in bipolar disorder (BD), but it also adversely impacts the course, outcome, and treatment of BD. The present review provides an overview of the current trends in research on comorbid anxiety and BDs based on prior reviews and meta-analyses (n = 103), epidemiological surveys, and large-scale clinical studies. The results reiterated the fact that at least half of those with BD are likely to develop an anxiety disorder in their lifetimes and a third of them will manifest an anxiety disorder at any point of time. All types of anxiety disorders were equally common in BD. However, there was a wide variation in rates across different sources, with most of this discrepancy being accounted for by methodological differences between reports. Comorbid anxiety disorders negatively impacted the presentation and course of BD. This unfavourable clinical profile led to poorer outcome and functioning and impeded treatment of BD. Despite the extensive body of research there was paucity of data on aetiology and treatment of anxiety disorder comorbidity in BD. Nevertheless, the substantial burden and unique characteristics of this comorbidity has important clinical and research implications.

The aldehyde dehydrogenase 2 polymorphisms on neuropsychological performance in bipolar II disorder with or without comorbid anxiety disorder

Anxiety disorders (ADs), the most common comorbid illnesses with bipolar disorder (BP) has been reported to associate with dopamine system. Dopamine, metabolized to 3,4-dihydroxyphenylacetic acid (DOPAC) by aldehyde dehydrogenase 2 (ALDH2), and the distribution of the ALDH2*1/*1, and ALDH2*1/*2+ALDH*2/*2 alleles in the Han Chinese general population is relatively equal. The association between dopamine metabolic enzymes and cognitive performance in patients with bipolar II disorder (BP-II) comorbid with AD is unclear. This study proposed to explore the role of ALDH2 polymorphisms on neuropsychological performance between BP-II comorbid with or without AD. One hundred ninety-seven BP-II patients with and without a comorbid AD were recruited and compared with 130 healthy controls (HCs). A polymerase chain reaction and a restriction fragment length polymorphism analysis were used to determine genotypes for ALDH2, and study participants underwent neuropsychological tests. An interaction between AD comorbidity and the ALDH2 polymorphisms was found in different domain of cognitive dysfunction in the BP-II patients. The ALDH2 polymorphisms might have different effects on the neuropsychological performance of BP-II patients with and without comorbid AD.

Prevalence and Associated Features of Anxiety Disorder Comorbidity in Bipolar Disorder: A Meta-Analysis and Meta-Regression Study

Objective: Bipolar disorder is highly comorbid with anxiety disorders, however current and lifetime comorbidity patterns of each anxiety disorder and their associated features are not well studied. Here, we aimed to conduct a meta-analysis and meta-regression study of current evidence. Method: We searched PubMed to access relevant articles published until September 2015, using the keywords "Bipolar disorder" or "Affective Psychosis" or "manic depressive" separately with "generalized anxiety," "panic disorder," "social phobia," "obsessive compulsive," and "anxiety." Variables for associated features and prevalence of anxiety disorders were carefully extracted. Results: Lifetime any anxiety disorder comorbidity in BD was 40.5%; panic disorder (PD) 18.1%, generalized anxiety disorder (GAD) 13.3%, social anxiety disorder (SAD) 13.5% and obsessive compulsive disorder (OCD) 9.7%. Current any anxiety disorder comorbidity in BD is 38.2%; GAD is 15.2%, PD 13.3%, SAD 11.7%, and OCD 9.9%. When studies reporting data about comorbidities in BDI or BDII were analyzed separately, lifetime any anxiety disorder comorbidity in BDI and BDII were 38% and 34%, PD was 15% and 15%, GAD was 14% and 16.6%, SAD was 8% and 13%, OCD was 8% and 10%, respectively. Current any DSM anxiety disorder comorbidity in BDI or BDII were 31% and 37%, PD was 9% and 13%, GAD was 8% and 12%, SAD was 7% and 11%, and OCD was 8% and 7%, respectively. The percentage of manic patients and age of onset of BD tended to have a significant impact on anxiety disorders. Percentage of BD I patients significantly decreased the prevalence of panic disorder and social anxiety disorder. A higher rate of substance use disorder was associated with greater BD-SAD comorbidity. History of psychotic features significantly affected current PD and GAD. Conclusions: Anxiety disorder comorbidity is high in BD with somewhat lower rates in BDI vs BDII. Age of onset, substance use disorders, and percentage of patients in a manic episode or with psychotic features influences anxiety disorder comorbidity.

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.

Prevalence, impact and treatment of generalised anxiety disorder in bipolar disorder: a systematic review and meta-analysis

QUESTION

Recent data suggest that anxiety disorders are as often comorbid with bipolar disorder (BD) as with unipolar depression; however, less attention has been paid to comorbidity of anxiety disorders with BD. Generalised anxiety disorder (GAD) is one of the most prevalent anxiety disorders that is highly comorbid with other mental disorders. We carried out a systematic review and meta-analysis to assess the degree of comorbidity between GAD and BD.

STUDY SELECTION AND ANALYSIS

We searched for all studies, which included primary data concerning the existence of GAD in patients with BD. The literature search strategy, selection of publications and the reporting of results have been conducted with PRISMA guidelines. The meta-analysis calculated prevalence estimates using the variance-stabilising Freeman-Tukey double arcsine transformation. We applied the inverse variance method using both fixed-effects and random-effects models to estimate summary effects for all combined studies. Heterogeneity was assessed and measured with Cochran's Q and I(2) statistics, respectively.

FINDINGS

The current meta-analysis analysed data from 28 independent studies and a total of 2975 patients from point prevalence studies and 4919 patients from lifetime studies. The overall random-effects point prevalence of GAD in patients with BD was 12.2% (95% CI 10.9% to 13.5%) and the overall random-effects lifetime estimate was 15.1% (95% CI 9.7% to 21.5%). Both estimates reported significant heterogeneity (94.0% and 94.7%, respectively).

CONCLUSIONS

Published studies report prevalence rates with high heterogeneity and consistently higher than those typically reported in the general population. It is believed that comorbid GAD might be associated with a more severe BD course and increased suicidality, and it is unknown how best to treat such conditions. The current meta-analysis confirms that GAD is highly prevalent in BD and the rate is higher in comparison to those in the general population.

A Lifetime Prevalence of Comorbidity Between Bipolar Affective Disorder and Anxiety Disorders: A Meta-analysis of 52 Interview-based Studies of Psychiatric Population

BACKGROUND

Bipolar affective disorder has a high rate of comorbidity with a multitude of psychiatric disorders and medical conditions. Among all the potential comorbidities, co-existing anxiety disorders stand out due to their high prevalence.

AIMS

To determine the lifetime prevalence of comorbid anxiety disorders in bipolar affective disorder under the care of psychiatric services through systematic review and meta-analysis.

METHOD

Random effects meta-analyses were used to calculate the lifetime prevalence of comorbid generalised anxiety disorder, panic disorder, social anxiety disorder, specific phobia, agoraphobia, obsessive compulsive disorder and posttraumatic stress disorder in bipolar affective disorder.

RESULTS

52 studies were included in the meta-analysis. The rate of lifetime comorbidity was as follows: panic disorder 16.8% (95% CI 13.7-20.1), generalised anxiety disorder 14.4% (95% CI 10.8-18.3), social anxiety disorder13.3% (95% CI 10.1-16.9), post-traumatic stress disorder 10.8% (95% CI 7.3-14.9), specific phobia 10.8% (95% CI 8.2-13.7), obsessive compulsive disorder 10.7% (95% CI 8.7-13.0) and agoraphobia 7.8% (95% CI 5.2-11.0). The lifetime prevalence of any anxiety disorders in bipolar disorder was 42.7%.

CONCLUSIONS

Our results suggest a high rate of lifetime concurrent anxiety disorders in bipolar disorder. The diagnostic issues at the interface are particularly difficult because of the substantial symptom overlap. The treatment of co-existing conditions has clinically remained challenging.

Interaction of DRD2TaqI, COMT, and ALDH2 genes associated with bipolar II disorder comorbid with anxiety disorders in Han Chinese in Taiwan

It is hypothesized that dopaminergic genes-dopamine type-2 receptor (DRD2), aldehyde dehydrogenase 2 (ALDH2), and catechol-O-methyltransferase (COMT)-are associated with bipolar disorder (BP) and anxiety disorder (AD). Bipolar II (BP-II) is reported to be highly comorbid with AD. We examined whether interactions among these three genes are susceptibility factors in BP-II with AD (BP-II(+AD)) and without AD (BP-II(-AD)). In this study, we hypothesize that the interaction of the dopaminergic genes between BP-II(+AD) and BP-II(-AD) is significant different. We recruited 1260 participants: 495 with BP-II(-AD), 170 with BP-II(+AD), and 595 healthy controls without BP-II or AD. Genotyping was done using polymerase chain reactions plus restriction fragment length polymorphism analysis. Genotypic frequencies of the DRD2TaqIA, COMT, and ALDH2 polymorphisms between the two BP-II groups were nonsignificant. In logistic regression, the ALDH2 and DRD2TaqIA genes showed a main effect that was protective against BP-II(-AD) (odds ratio [OR] = 0.497, p = 0.010, and OR = 0.415, p = 0.017, respectively). The interaction of DRD2TaqIA A1/A1 and ALDH2*1/*1 had a significant risk effect on the BP-II(-AD) group (OR = 7.177, p < 0.001). However, the interaction of DRD2TaqIA A1/A1, ALDH2*1/*1, and COMTMet/Met&Val/Met become a weak protective factor against BP-II(-AD) (OR = 0.205, p = 0.047). All of the significant results described above are found only in BP-II(-AD). This study supports the hypothesis the interaction of the dopaminergic genes between BP-II(+AD) and BP-II(-AD) is significant different,, and provides additional evidence that the DRD2TaqIA A1/A1, ALDH2*1/*1 and COMT genes interact in BP-II(-AD) but not in BP-II(+AD).

The effects of ethnic, social and cultural factors on axis I comorbidity of bipolar disorder: results from the clinical setting in Korea

OBJECTIVE

Ethnic, social and cultural factors contribute to axis I comorbid conditions in bipolar disorder (BPD). Korea has strict laws against illicit drugs and a relatively permissive prevailing attitude toward alcohol. The present study aimed to explore the lifetime axis I comorbidity rate in patients with BPD in Korea.

METHODS

Clinically stable patients with bipolar I (n=222) and bipolar II (n=194) disorders were recruited from four tertiary medical centers in Korea. The subjects׳ diagnoses and axis I comorbid conditions were evaluated using the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID) and the Korean version of the Diagnostic Interview for Genetic Studies (K-DIGS). The lifetime prevalence of anxiety disorders, substance use disorders and eating disorders was explored. The prevalence of these axis I comorbid conditions was compared with data from prior studies in other countries and to data concerning the general Korean population.

RESULTS

A total of 45.1% of all subjects had at least one axis I comorbid condition. Anxiety disorders (30.2%) were the most common comorbidity, followed by alcohol use disorders (16.8%). Males with BPD showed a higher rate of alcohol dependence compared to the general male population and females with BPD showed a greater risk of having alcohol use disorder compared to the general female population. The rate of drug use disorder was extremely low (1.7%), and only one subject had an illicit-drug-related problem.

LIMITATION

Cross-sectional studies.

CONCLUSION

Comorbid conditions of Korean patients with BPD showed a distinct pattern, which is associated with the ethnic, social and cultural characteristics in Korea.

Gender-specific association of the SLC6A4 and DRD2 gene variants in bipolar disorder

Findings on the association between the risk for developing bipolar disorder and the functions of the serotonin transporter-linked polymorphic region gene (5-HTTLPR) and dopamine D2 receptor gene (DRD2) variants are contradictory. One explanation for this is that a gender difference may exist for genetic contributions. We compared the gender-related main effects and the gene-to-gene interaction between serotonin transporter gene (SLC6A4) and DRD2 in adult male and female patients with bipolar I (BP-I) and bipolar II (BP-II) disorder. Patients with BP-I (n = 400) and BP-II (n = 493), and healthy controls (n = 442) were recruited from Taiwan's Han Chinese population. The genotypes of the 5-HTTLPR and DRD2 Taq-IA polymorphisms were determined using polymerase chain reaction-restriction fragment length polymorphism analysis. Logistic regression analysis showed a significant gender-specific association of the DRD2 A1/A1 and the 5-HTTLPR S/S, S/LG , and LG/LG (S+) (p = 0.01) genotypes in men with BP-I (p = 0.002 and 0.01, respectively) and BP-II (p = 0.001 and 0.007, respectively), but not in women. A significant interaction for the DRD2 A1/A1 and 5-HTTLPR S+ polymorphisms was also found only in men with BP-I and BP-II (p = 0.003 and 0.001, respectively). We provide preliminary evidence for a gender-specific effect of the SLC6A4 and DRD2 gene variants for the risk of BP-I and of BP-II. We also found gender-specific interaction between 5-HTTLPR and DRD2 Taq-IA polymorphisms in patients with bipolar disorder.

Risk factors for an anxiety disorder comorbidity among Thai patients with bipolar disorder: results from the Thai Bipolar Disorder Registry

BACKGROUND

The aim of the study was to determine in a clinical setting the risk factors for current anxiety disorder (AD) comorbidity among Thai patients with bipolar disorder (BD), being treated under the Thai Bipolar Disorder Registry Project (TBDR).

METHODS

The TBDR was a multisite naturalistic study conducted at 24 psychiatric units (ie, at university, provincial mental, and government general hospitals) between February 2009 and January 2011. Participants were in- or out-patients over 18 years of age who were diagnosed with BD according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Instruments used in this study included the Thai Mini International Neuropsychiatric Interview version 5; Thai Montgomery-Åsberg Depression Rating Scale (MADRS); Thai Young Mania Rating Scale; Clinical Global Impression of Bipolar Disorder-Severity (CGI-BP-S), CGI-BP-S-mania, CGI-BPS-depression, and CGI-BP-S-overall BP illness; and the Thai SF-36 quality of life questionnaire.

RESULTS

Among the 424 BD patients, 404 (95.3%) had BD type I. The respective mean ± standard deviation of age of onset of mood disturbance, first diagnosis of BD, and first treatment of BD was 32.0±11.9, 36.1±12.2, and 36.2±12.2 years. The duration of illness was 10.7±9.0 years. Fifty-three (12.5%) of the 424 participants had a current AD while 38 (9%) had a substance use disorder (SUD). The univariate analysis revealed 13 significant risks for current AD comorbidity, which the multivariate analysis narrowed to age at first diagnosis of BD (odds ratio =0.95, P<0.01), family history of SUD (odds ratio =2.18, P=0.02), and having a higher current MADRS score (odds ratio =1.11, P<0.01).

CONCLUSION

A diagnosis of AD comorbid with BD is suggested by early-age onset of BD together with a higher MADRS score and a family history of SUD. The likelihood of AD comorbidity decreases by 5% with each passing year; early-age onset of BD is a risk while later age onset is protective. Our results underscore how SUD within the family significantly contributes to the risk of an AD comorbidity.

Genetic variants of the BDNF and DRD3 genes in bipolar disorder comorbid with anxiety disorder

BACKGROUND

The high comorbidity rate between bipolar disorder (BP) and anxiety disorder (AD) has been studied in depth. This comorbidity is not as high in Han Chinese in Taiwan. Therefore, we explored the genetic effects BP comorbid with AD.

METHODS

We recruited 1316 participants: 286 with BP-I, 681 with BP-II, and 349 healthy Controls. Genotypes of the BDNF Val66Met and DRD3 Ser9Gly polymorphisms were determined using polymerase chain reactions plus restriction fragment length polymorphism analysis.

RESULTS

The DRD3 Ser9Gly polymorphism was associated with BP-II comorbid with AD (BPII(+AD)), and the BDNF Val66Met polymorphism was associated with BP-I comorbid with AD (BPI(+AD)). An interaction between the Val/Val genotype of the BDNF Val66Met and Gly/Gly polymorphism of the DRD3 Ser9Gly was found in BPII(+AD), but not in BP-II not comorbid with AD (BPI(-AD)) compared with healthy Controls.

LIMITATION

The low comorbidity rate of AD in both BP subtypes, especially BP-I, limit generalizing our findings.

CONCLUSION

The involvement of the dopaminergic pathway in AD was confirmed, particularly with BP-II rather than BP-I. Because the Val/Val genotype of the BDNF Val66Met polymorphism, rather than the other two polymorphisms, has been associated with anxiety, it seems to affect BP-I comorbid with AD without the involvement of the DRD3 Seg9Gly polymorphism, but may modify the involvement of DRD3 Gly/Gly in BP-II comorbid with AD.

Correlates of current suicide risk among Thai patients with bipolar I disorder: findings from the Thai Bipolar Disorder Registry

BACKGROUND

The Thai Bipolar Disorder Registry was a prospective, multisite, naturalistic study conducted in 24 hospitals across Thailand. This study aimed to examine the correlates of current suicide risk in Thai patients with bipolar I disorder.

METHODS

Participants were adult inpatients or outpatients with bipolar disorder, based on the Diagnosis and Statistical Manual of Mental Disorders, fourth edition. All were assessed by using the Mini International Neuropsychiatric Interview (MINI), version 5. The severity of current suicide risk was determined by using the total score of the MINI suicidality module. Mood symptoms were assessed by using the Young Mania Rating Scale and the Montgomery Asberg Depression Rating Scale.

RESULTS

The data of 383 bipolar I disorder patients were included in the analyses. Of these, 363 (94.8%) were outpatients. The mean (standard deviation) of the MINI suicide risk score was 1.88 (5.0). The demographic/clinical variables significantly associated with the MINI suicide risk scores included age, number of overall previous episodes, the Young Mania Rating Scale score, the Montgomery Asberg Depression Rating Scale scores, and the Clinical Global Impression Severity of Illness Scale for Bipolar Disorder mania score, depression score, and overall score. The variables affecting the differences of suicide risk scores between or among groups were type of first mood episode, a history of rapid cycling, anxiety disorders, and alcohol use disorders. The stepwise multiple linear regression model revealed that the Montgomery Asberg Depression Rating Scale score (β=0.10), a history of rapid cycling (β=6.63), anxiety disorders (β=2.16), and alcohol use disorders (β=2.65) were significantly correlated with the suicide risk score (all P<0.01).

CONCLUSION

A history of rapid cycling, severity of depressive episode, current anxiety disorders, and current alcohol use disorders correlate with current suicide risk among Thai bipolar I disorder patients. Further studies in larger sample sizes are warranted.

COMT and BDNF interacted in bipolar II disorder not comorbid with anxiety disorder

Bipolar disorder (BP), especially bipolar II disorder (BP-II), is highly comorbid with anxiety disorder (AD). Monoaminergic dysfunction has been implicated in the pathogenesis of BP, it may be important to investigate genes such as the catechol-O-methyltransferase (COMT), involved in monoamine metabolism and brain-derived neurotrophic factor (BDNF) genes, modulating the monoamine system. We therefore examined the association of the COMT Val158Met and BDNF Val66Met polymorphisms with BP-II with and without comorbidity of AD, and possible interactions between these genes. Seven hundred and seventy-one participants were recruited: 314 with bipolar-II without AD, 117 with bipolar-II with AD, and 340 healthy controls. The genotypes of the COMT and BDNF polymorphisms were determined using polymerase chain reactions plus restriction fragment length polymorphism analysis. Logistic regression analysis showed a significant effect of the COMT and the BDNF polymorphisms, and a significant interaction effect for the Val/Val genotypes of the BDNF Val66Met polymorphism and the COMsT Val158Met Val/Met and Met/Met genotypes (P=0.007, 0.048) discriminated between BP-II without AD patients and controls. Our findings provide initial evidence that the COMT and BDNF genes interact in bipolar-II without AD. Our findings suggest the involvement of dopaminergic pathway in the pathogenesis of bipolar-II.