Suicide attempts in bipolar I and bipolar II disorder: a review and meta-analysis of the evidence

The 'true' prevalence of bipolar II disorder

PURPOSE OF REVIEW

Many studies - including meta-analyses - do not distinguish between bipolar I and II disorder. The aim of this study is to review the recent literature on the prevalence, correlates, consequences, and treatment patterns of bipolar II disorder.

RECENT FINDINGS

In the past 2 years, several important studies have been conducted in the bipolar II field. The World Mental Health Survey initiative provides us with prevalence rate across 11 countries, while several meta-analyses on suicide and neurocognition directly compared bipolar I with bipolar II, informing us on the severe consequences of bipolar II disorder. Results from studies showed that the lifetime prevalence rate of bipolar II disorder in adults across 11 countries was 0.4%. Rates of bipolar II disorder in prospective studies of adolescents are substantially greater, with lifetime rates approaching 3-4%.

SUMMARY

Evidence from these studies regarding comparable clinical consequences, patterns of comorbidity, suicide attempts, family history, and treatment patterns to bipolar I disorder document the validity of the bipolar II subtype.

Treatment-induced manic switch in the course of unipolar depression can predict bipolarity: cluster analysis based evidence

BACKGROUND

Antidepressants are known to induce manic switch in patients with depression. Treatment-induced mania is not considered as bipolar disorder in DSM IV. The aim of this study was to assess whether clinical characteristics of patients with unipolar depression with a history of treatment-induced mania were similar to those of patients with bipolar disorder.

METHOD

The study included 217 consecutive patients with DSM-IV mood disorders, diagnosed as: bipolar disorder type I (BP-I, n = 58) or type II (BP-II, n = 18) whose first episodes were depression, recurrent (unipolar) major depressive disorder with a history of antidepressant treatment-induced mania (switchers = sUD; n = 61) and without such an event (rUD; n = 80). First, the groups were compared with regard to clinical features and course specifiers using variance and chi-square analysis. Variables that differed significantly between the four groups were included in two-step cluster analysis to explore naturally occurring subgroups in all diagnoses. Subsequently, the relationship between the naturally occurring clusters and pre-defined DSM-IV diagnoses were investigated.

RESULTS

Two-step cluster analysis revealed two different naturally occurring groups. Higher severity of depressive episodes, with higher rate of melancholic features, higher number of hospitalization and suicide attempts were represented in one cluster where switchers (77%), bipolar I (94.8%) and II (83.3%) patients clustered together.

CONCLUSION

The findings of this study confirm that treatment-induced mania is a clinical phenomenon that belongs within the bipolar spectrum rather than a coincidental treatment complication, and that it should be placed under "bipolar disorders" in future classification systems.

LIMITATIONS

The study includes the limitations of any naturalistic retrospective study.

Subthreshold bipolarity: diagnostic issues and challenges

BACKGROUND

Research suggests that current diagnostic criteria for bipolar disorders may fail to include milder, but clinically significant, bipolar syndromes and that a substantial percentage of these conditions are diagnosed, by default, as unipolar major depression. Accordingly, a number of researchers have argued for the upcoming 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) to better account for subsyndromal hypomanic presentations.

METHODS

The present paper is a critical review of research on subthreshold bipolarity, and an assessment of some of the challenges that researchers and clinicians might face if the DSM-5 were designed to systematically document subsyndromal hypomanic presentations.

RESULTS

Individuals with major depressive disorder (MDD) who display subsyndromal hypomanic features, not concurrent with a major depressive episode, have a more severe course compared to individuals with MDD and no hypomanic features, and more closely resemble individuals with bipolar disorder on a number of clinical validators.

CONCLUSION

There are clinical and scientific reasons for systematically documenting subsyndromal hypomanic presentations in the assessment and diagnosis of mood disorders. However, these benefits are balanced with important challenges, including (i) the difficulty in reliably identifying subsyndromal hypomanic presentations, (ii) operationalizing subthreshold bipolarity, (iii) differentiating subthreshold bipolarity from borderline personality disorder, (iv) the risk of over-diagnosing bipolar spectrum disorders, and (v) uncertainties about optimal interventions for subthreshold bipolarity.

Clinical and dimensional characteristics of euthymic bipolar patients with or without suicidal behavior

BACKGROUND

The clinical and dimensional features associated with suicidal behaviour in bipolar patients during euthymic states are not well characterised.

METHODS

In a sample of 652 euthymic bipolar patients, we assessed clinical features with the Diagnostic Interview for Genetics Studies (DIGS) and dimensional characteristics with questionnaires measuring impulsivity/hostility and affective lability/intensity. Bipolar patients with and without suicidal behaviour were compared for these clinical and dimensional variables.

RESULTS

Of the 652 subjects, 42.9% had experienced at least one suicide attempt. Lifetime history of suicidal behaviour was associated with being a woman, a history of head injury, tobacco misuse and indicators of severity of bipolar disorder including early age at onset, high number of depressive episodes, positive history of rapid cycling, alcohol misuse and social phobia. Indirect hostility and irritability were dimensional characteristics associated with suicidal behaviour in bipolar patients, whereas impulsivity and affective lability/intensity were not associated with suicidal behaviour.

LIMITATIONS

This study had a retrospective design with no replication sample.

CONCLUSIONS

Bipolar patients with earlier onset, mood instability (large number of depressive episodes, rapid cycling) and/or particular addictive and anxiety comorbid disorders might be at high risk of suicidal behaviour. In addition, hostility dimensions (indirect hostility and irritability), may be trait components associated with suicidal behaviour in euthymic bipolar patients.

Early intervention for bipolar disorder: current imperatives, future directions

OBJECTIVES: The objective of this article is to discuss the rationale/background for early intervention in bipolar disorder. METHOD: Narrative review. RESULTS: There are often significant delays before the diagnosis of bipolar disorder is made and effective management initiated. Growing evidence from both preclinical and clinical literature points to a clear need for improved early identification and early intervention in bipolar disorder. Increasing efforts are being applied to the identification of those at high risk of onset of bipolar disorder. It is hoped that identification of an early prodrome of illness will allow preventative measures to be taken. CONCLUSIONS: There is a clear rationale for improved early identification and early intervention in bipolar disorder.

Striatal and cortical midline activation and connectivity associated with suicidal ideation and depression in bipolar II disorder

BACKGROUND

Considerable evidence implicates dysfunction of striatal and cortical midline structure (CMS) circuitry in mood disorders. Whether such aberrations exist in bipolar II depression is unknown.

METHODS

Sixteen unmedicated subjects with bipolar II depression and 19 healthy controls were studied using functional MRI and a motor activation paradigm. Analyses of both activation and functional connectivity were conducted.

RESULTS

A history of suicidal ideation (SI) was negatively correlated with activation of the left putamen while depression severity was positively correlated with activation of the left thalamus. The superior bilateral putamen was simultaneously correlated with depression severity and anti-correlated with SI. Striatal functional connectivity was altered with the bilateral CMS and right inferior parietal lobule. Depression severity was correlated with strength of connectivity between the bilateral striatum and the right lingual gyrus and left cerebellum.

LIMITATIONS

Only males experiencing an episode of major depression were studied.

CONCLUSIONS

Striatal and CMS circuit abnormalities likely contribute to the neurobiology of bipolar II depression. Altered connectivity of the striatum may directly impact depression severity. Further, dissociable components of activation associated with depression severity and suicidal ideation may exist. Finally, the motor activation paradigm used in this study appears to be a useful probe of some neural processes underlying bipolar II depression.

Aberrant emotional processing in posterior cortical midline structures in bipolar II depression

Bipolar II depression is a serious and disabling illness associated with significant impairment and high rates of suicide attempts. However, mechanisms underlying emotional dysregulation in this condition are poorly characterized. The goal of this work was to investigate one component of emotional processing in this disorder, brain activation associated with exposure to emotional faces. Functional MRI was used to study 16 unmedicated male subjects with bipolar II depression and 19 healthy male controls. The activation paradigm exposed subjects to happy, fearful and neutral faces. The two key findings of this study were as follows. First, bipolar subjects demonstrated significantly decreased activation in response to happy facial expression in the left posterior cortical midline structures (CMS) and frontal cortex. Second, depression severity was positively correlated with activation of the posterior CMS and other regions. Our results suggest that mechanisms involving CMS dysfunction may play a role in the neurobiology of bipolar II depression as has been demonstrated for unipolar illness. Further investigations of CMS function in bipolar spectrum disorders are warranted.

Mood stabilizers for patients with bipolar disorder: the state of the art

Bipolar disorder (BD) is a prevalent and disabling condition, often comorbid with other medical and psychiatric conditions and frequently misdiagnosed. International treatment guidelines for BD recommend the use of mood stabilizers - either in monotherapy or in association - as the gold standard in both acute and long-term therapy. Commonly used in the clinical practice of BD, mood stabilizers have represented an evolving field over the last few years. The concept of stabilization, in fact, has been stressed as the ultimate objective of the treatment of BD, given the chronic and recurrent nature of the illness, which accounts for its significant levels of impairment and disability. To date, different compounds are included within the broad class of mood stabilizers, with lithium, anticonvulsants and, more recently, atypical antipsychotics being the most representative agents. This article is aimed at providing an updated review of the available literature in relation to the role of mood stabilizers in BD, with particular emphasis on their mechanism of action, main clinical aspects and specific use in the different phases of BD treatment, according to the most recently published international treatment guidelines.

Co-occurring manic symptomatology as a dimension which may help explaining heterogeneity of depression

BACKGROUND

The dichotomous distinction between unipolar and bipolar disorders may be challenged by heterogeneity within diagnoses and overlap between different diagnoses. A broad mood disorder category in which patients differ as a result of variation along separate manic and depressive mood dimensions can be proposed. To test this, it is hypothesized that heterogeneity in clinical and other features of subjects selected for unipolar depression can be partly explained by coexisting manic symptoms.

METHODS

A cohort selected for unipolar depressive disorder was followed up for two years at which time co-occurring manic symptoms were assessed, yielding four groups with increasing manic symptomatology: i) pure unipolar depressive disorder (n=1598), ii) unipolar depressive disorder with subthreshold manic symptomatology (n=64), iii) bipolar II disorder (n=39), and iv) bipolar I disorder (n=86). Multivariate logistic regression and analyses of covariance controlled for depression severity were used to investigate whether patients with increasing manic symptomatology could be differentiated from patients with pure depressive disorder.

RESULTS

Male gender, a lower age at first episode, a history of suicide attempts and increased aggressive cognitions were independently associated with an increase in manic symptoms. The additional presence of (hypo)mania was associated with greater depression severity and more disability than pure depressive disorder.

LIMITATIONS

The groups with manic symptomatology (subthreshold, hypomania and mania) were considerably smaller compared to the pure depression group.

CONCLUSIONS

The heterogeneity in depressive illness can be partly explained by the coexisting variation along the manic symptom dimension. Co-occurring manic symptoms should be taken into account in depression and a symptom dimensional approach of mood disorders may provide phenotypes that are more informative than current mood disorder categories.

Suicidal obsessions as dose dependent side-effect of clozapine

OBJECTIVE

Although numerous reports suggest that different atypical antipsychotics can exacerbate or induce (de novo) obsessive-compulsive symptoms, there is no report of the development of ego-dystonic, suicidal obsessions during treatment with these medications. Here, the authors report the first case of clozapine-induced suicidal obsessions.

METHOD

The authors report a case of a patient diagnosed with bipolar disorder and who developed suicidal obsessions in the weeks after the dose of clozapine was increased from 150 mg/day to 300 mg/day.

RESULTS

Symptoms quickly resolved after the treatment with clozapine was changed to the treatment with quetiapine and sodium valproate. Suicidal obsessions decreased promptly, within a few days, and disappeared completely when the dose of clozapine was 100 mg/day, quetiapine 600 mg/day, and sodium valproate 900 mg/day, 16 days after the initiation of changes in the medications.

CONCLUSION

The case report emphasizes the crucial need of differentiation between genuine suicidal desires and ego-dystonic suicidal obsessions. The authors suggest that in similar cases a change in antipsychotic medications to those with stronger antidopaminergic properties and lower 5HT2 receptor affinity should be considered, but also assume that the use of sodium valproate in treatment of obsessive-compulsive symptoms deserves further study.

Study of DSM-IV Axis I psychiatric disorders in patients with refractory complex partial seizures using a short structured clinical interview

Psychiatric disorders are a source of significant comorbidity in patients with refractory epilepsy, yet are often underrecognized. We assessed the prevalence of DSM-IV Axis I psychiatric disorders using a short structured clinical interview (Mini-International Psychiatric Interview [MINI]) in patients with medically refractory complex partial seizures. Consecutive patients with refractory epilepsy being evaluated with video/EEG monitoring and imaging for seizure focus localization and lateralization underwent MINI evaluation to assess for the presence of psychiatric disorders. Among 117 patients (74 male, 43 female) studied, 57 (48.7%) had at least one psychiatric disorder; 19 (16.2%) had depression, 10 (8.5%) dysthymia, 27 (23.0%) anxiety disorder, and 11(9.4%) other disorders. Most clinical features and epilepsy-related variables had no significant association with psychiatric disorder on logistic regression analysis. Almost half of the patients with refractory focal seizures have a coexistent psychiatric disorder, and its presence or absence cannot be predicted by their clinical profiles. All patients should be assessed and treated for psychiatric comorbidity to improve overall quality of life.

Self-esteem in remitted bipolar disorder patients: a meta-analysis

OBJECTIVES

Low self-esteem has been found to be a risk factor for depression in major depressive disorder (MDD). In contrast, the role of self-esteem in bipolar disorder (BD) is still uncertain. In order to examine the characteristics of self-esteem in BD, we synthesized studies comparing self-esteem in BD patients with self-esteem in MDD patients and in normal controls.

METHODS

Database searches and identification of studies were conducted by two of the authors independently. Remission of BD and MDD was a major selection criterion. The results were generated through meta-analyses.

RESULTS

Random-effects models of 19 between-group comparisons (N= 1,838) suggested that the self-esteem of remitted BD patients was significantly lower than that of normal controls (Cohen's d= -0.83), while significantly higher than that of remitted MDD patients (Cohen's d= 0.54). Fail-safe numbers and tests for funnel plot asymmetry indicated that the results were robust and unlikely to reflect publication biases. Additional studies indicated that self-esteem may take a fluctuating course during remission of BD.

CONCLUSIONS

By revealing that BD patients do experience low self-esteem, the findings implicate a need for further understanding the causes and therapeutic impact of such abnormality in BD.

Brain-derived neurotrophic factor as a biomarker for mood disorders: an historical overview and future directions

Mood disorders, such as major depressive disorder (MDD) and bipolar disorder (BPD), are the most prevalent psychiatric conditions, and are also among the most severe and debilitating. However, the precise neurobiology underlying these disorders is currently unknown. One way to combat these disorders is to discover novel biomarkers for them. The development of such biomarkers will aid both in the diagnosis of mood disorders and in the development of effective psychiatric medications to treat them. A number of preclinical studies have suggested that the brain-derived neurotrophic factor (BDNF) plays an important role in the pathophysiology of MDD. In 2003, we reported that serum levels of BDNF in antidepressant-naive patients with MDD were significantly lower than those of patients medicated with antidepressants and normal controls, and that serum BDNF levels were negatively correlated with the severity of depression. Additionally, we found that decreased serum levels of BDNF in antidepressant-naive patients recovered to normal levels associated with the recovery of depression after treatment with antidepressant medication. This review article will provide an historical overview of the role played by BDNF in the pathophysiology of mood disorders and in the mechanism of action of therapeutic agents. Particular focus will be given to the potential use of BDNF as a biomarker for mood disorders. BDNF is initially synthesized as a precursor protein proBDNF, and then proBDNF is proteolytically cleaved to the mature BDNF. Finally, future perspectives on the use of proBDNF as a novel biomarker for mood disorders will be discussed.

Evidence of altered DNA integrity in the brain regions of suicidal victims of Bipolar Depression

Deoxyribonucleic acid (DNA) integrity plays a significant role in cell function. There are limited studies with regard to the role of DNA damage in bipolar affective disorder (BP). In the present study, we have assessed DNA integrity, conformation, and stability in the brain region of bipolar depression (BD) patients (n=10) compared to age-matched controls (n=8). Genomic DNA was isolated from 10 postmortem BD patients' brain regions (frontal cortex, Pons, medulla, thalamus, cerebellum, hypothalamus, Parietal, temporal, occipital lobe, and hippocampus) and from the age-matched control subjects. DNA from the frontal cortex, pons, medulla, and thalamus showed significantly higher number of strand breaks in BD (P<0.01) compared to the age-matched controls. However, DNA from the hippocampus region was intact and did not show any strand breaks. The stability studies also indicated that the melting temperature and ethidium bromide binding pattern were altered in the DNA of BD patients' brain regions, except in the hippocampus. The conformation studies showed B-A or secondary B-DNA conformation (instead of the normal B-DNA) in BD patients' brain regions, with the exception of the hippocampus. The levels of redox metals such as Copper (Cu) and Iron (Fe) were significantly elevated in the brain regions of the sufferers of BD, while the Zinc (Zn) level was decreased. In the hippocampus, there was no change in the Fe or Cu levels, whereas, the Zn level was elevated. There was a clear correlation between Cu and Fe levels versus strand breaks in the brain regions of the BD. To date, as far as we are aware, this is a new comprehensive database on stability and conformations of DNA in different brain regions of patients affected with BD. The biological significance of these findings is discussed here.