Are there subtypes of bipolar depression?

Latent Profile Analysis of Suicidal Ideation in Chinese Individuals with Bipolar Disorder

Individuals with bipolar disorder (BD) have a greater suicide risk than the general population. In this study, we employed latent profile analysis (LPA) to explore whether Chinese individuals with different phases of BD differed at the levels of suicidal ideation. We recruited 517 patients. Depressive symptoms were measured using the 24-item Hamilton Depression Rating Scale (HAMD-24), and manic symptoms were evaluated using the Young Mania Rating Scale (YMRS). The extent of suicidal thoughts was determined through the Beck Scale for Suicide Ideation (BSSI). The scores of HAMD and YMRS were used to perform LPA. LPA categorized participants into three classes: one exhibiting severe depressive and mild manic symptomatology, another showing severe depressive and severe manic symptomatology, and the third one displaying severe depressive and intermediate manic symptomatology. Suicidal ideation levels were found to be remarkably elevated across all three classes. Additionally, the three classes showed no significant differences in terms of suicidal ideation. Our research confirms the link between depressive symptoms and suicide, independent of the manic symptoms. These findings carry meaning as they provide insight into the suicide risk profiles within different phases of BD.

Exploration of mood spectrum symptoms during a major depressive episode: The impact of contrapolarity-Results from a transdiagnostic cluster analysis on an Italian sample of unipolar and bipolar patients

Background

Subthreshold hypomania during a major depressive episode challenges the bipolar-unipolar dichotomy. In our study we employed a cross-diagnostic cluster analysis - to identify distinct subgroups within a cohort of depressed patients.

Methods

A k-means cluster analysis— based on the domain scores of the Mood Spectrum Self-Report (MOODS-SR) questionnaire—was performed on a data set of 300 adults with either bipolar or unipolar depression. After identifying groups, between-clusters comparisons were conducted on MOODS-SR domains and factors and on a set of sociodemographic, clinical and psychometric variables.

Results

Three clusters were identified: one with intermediate depressive and poor manic symptomatology (Mild), one with severe depressive and poor manic symptomatology (Moderate), and a third one with severe depressive and intermediate manic symptomatology (Mixed). Across the clusters, bipolar patients were significantly less represented in the Mild one, while the DSM-5 “Mixed features” specifier did not differentiate the groups. When compared to the other patients, those of Mixed cluster exhibited a stronger association with most of the illness-severity, quality of life, and outcomes measures considered. After performing pairwise comparisons significant differences between “Mixed” and “Moderate” clusters were restricted to: current and disease-onset age, psychotic ideation, suicidal attempts, hospitalization numbers, impulsivity levels and comorbidity for Cluster B personality disorder.

Conclusions

In the present study, a clustering approach based on a spectrum exploration of mood symptomatology led to the identification of three transdiagnostic groups of patients. Consistent with our hypothesis, the magnitude of subthreshold (hypo)manic symptoms was related to a greater clinical severity, regardless of the main categorical diagnosis.

Latent class analysis of bipolar disorder symptoms and suicidal ideation and behaviors

Individuals with bipolar disorder are at increased risk of dying by suicide compared to healthy controls and those with unipolar depression. Previous studies show that depressive symptoms and mixed episodes of mania and depression are related to suicide. However, most of these studies adopt a variable-centered approach to understanding how specific symptoms relate to suicidal ideation, without addressing how these symptoms and symptom profiles relate to suicidal behaviors.

OBJECTIVES

Using latent class analysis, this study adopts a person-centered approach to examine whether subtypes of patients with bipolar disorder differ in their levels of suicidal ideation and behaviors.

METHODS

A total of 150 patients from a behavioral health outpatient clinic were recruited. Latent classes were generated based on self reports of their depressive and manic symptoms.

RESULTS

Five classes of patients with bipolar disorder were identified, namely, a minimal symptom, mania, moderately depressed, severely depressed, and mixed depression-mania subtypes. Those in the severely depressed and mixed depression-mania groups reported significantly higher levels of suicidal ideation and behaviors compared to the other groups.

CONCLUSIONS

Our findings provide further support for the strong relationship between depressive symptoms and suicidality. These findings are significant as they shed light on the different suicide risk profiles among a heterogenous group of patients with bipolar disorder. Name of clinical trial: Suicidal Behavior in Patients Diagnosed with Bipolar Disorder: The Roles of Biological and Childhood and Adult Environmental Risk Factors. ClinicalTrials.gov Identifier: NCT02604277.

Treatment of Bipolar Depression with Deep TMS: Results from a Double-Blind, Randomized, Parallel Group, Sham-Controlled Clinical Trial

Bipolar depression (BD) is a highly prevalent condition with limited therapeutic options. Deep (H1-coil) transcranial magnetic stimulation (dTMS) is a novel TMS modality with established efficacy for unipolar depression. We conducted a randomized sham-controlled trial to evaluate the efficacy and safety of dTMS in treatment-resistant BD patients. Patients received 20 sessions of active or sham dTMS over the left dorsolateral prefrontal cortex (H1-coil, 55 18 Hz 2 s 120% MT trains). The primary outcome was changes in the 17-item Hamilton Depression Rating Scale (HDRS-17) from baseline to endpoint (week 4). Secondary outcomes were changes from baseline to the end of the follow-up phase (week 8), and response and remission rates. Safety was assessed using a dTMS adverse effects questionnaire and the Young Mania Rating Scale to assess treatment-emergent mania switch (TEMS). Out of 50 patients, 43 finished the trial. There were 2 and 5 dropouts in the sham and active groups, respectively. Active dTMS was superior to sham at end point (difference favoring dTMS=4.88; 95% CI 0.43 to 9.32, p=0.03) but not at follow-up. There was also a trend for greater response rates in the active (48%) vs sham (24%) groups (OR=2.92; 95% CI=0.87 to 9.78, p=0.08). Remission rates were not statistically different. No TEMS episodes were observed. Deep TMS is a potentially effective and well-tolerated add-on therapy in resistant bipolar depressed patients receiving adequate pharmacotherapy.

Anxiety, irritability, and agitation as indicators of bipolar mania with depressive symptoms: a post hoc analysis of two clinical trials

Background

Symptoms of anxiety, irritability, and agitation (AIA) are prevalent among patients with bipolar I disorder (BD-I) mania with depressive symptoms, and could potentially be used to aid physicians in the identification of this more severe form of BD-I. Using data from two clinical trials, the aims of this post hoc analysis were to describe the phenomenology of bipolar mania in terms of AIA and depressive symptoms, and to evaluate the influence of these symptoms on the likelihood of remission during treatment.

Methods

Patients with a BD-I manic or mixed episode (Diagnostic and Statistical Manual of Mental Disorders IV criteria) were randomised to 3 weeks of double-blind treatment with asenapine, placebo, or olanzapine (active comparator). Anxiety was defined as a score of ≥3 on the Positive and Negative Syndrome Scale ‘anxiety’ item, irritability as a score of ≥4 on the Young Mania Rating Scale (YMRS) ‘irritability’ item, and agitation as a score of ≥3 on the YMRS ‘increased motor activity–energy’ item. Depressive symptoms were defined as a score of ≥1 on three or more individual Montgomery–Åsberg Depression Rating Scale (MADRS) items, or a MADRS Total score of ≥20.

Results

A total of 960 patients with BD-I were analysed, 665 with a manic episode and 295 with a mixed episode. At baseline, 61.4% had anxiety, 62.4% had irritability, 76.4% had agitation, and 34.0% had all three AIA symptoms (‘severe AIA’); 47.3% had three or more depressive symptoms, and 13.5% had a MADRS total score of ≥20. Anxiety, irritability, and severe AIA (but not agitation) were statistically significantly more common in patients with depressive symptoms. Patients with anxiety or severe AIA at baseline were statistically significantly less likely to achieve remission (YMRS total <12). In general, remission rates were higher with asenapine and olanzapine than with placebo, irrespective of baseline AIA or depressive symptoms.

Conclusions

Assessment of AIA symptoms in bipolar mania could enable physicians to identify patients with more severe depressive symptoms, allowing for appropriate intervention. Assessment and monitoring of AIA may help physicians to predict which patients may be harder to treat and at risk for self-harm.

Trial registration ClinicalTrials.gov NCT00159744, NCT00159796. Registered 8 September 2005 (retrospectively registered)

A pilot study to determine whether combinations of objectively measured activity parameters can be used to differentiate between mixed states, mania, and bipolar depression

BACKGROUND

Until recently, actigraphy studies in bipolar disorders focused on sleep rather than daytime activity in mania or depression, and have failed to analyse mixed episodes separately. Furthermore, even those studies that assessed activity parameters reported only mean levels rather than complexity or predictability of activity. We identified cases presenting in one of three acute phases of bipolar disorder and examined whether the application of non-linear dynamic models to the description of objectively measured activity can be used to predict case classification.

METHODS

The sample comprised 34 adults who were hospitalized with an acute episode of mania (n = 16), bipolar depression (n = 12), or a mixed state (n = 6), who agreed to wear an actiwatch for a continuous period of 24 h. Mean level, variability, regularity, entropy, and predictability of activity were recorded for a defined 64-min active morning and active evening period. Discriminant function analysis was used to determine the combination of variables that best classified cases based on phase of illness.

RESULTS

The model identified two discriminant functions: the first was statistically significant and correlated with intra-individual fluctuation in activity and regularity of activity (sample entropy) in the active morning period; the second correlated with several measures of activity from the evening period (e.g. Fourier analysis, autocorrelation, sample entropy). A classification table generated from both functions correctly classified 79% of all cases based on phase of illness (χ ² = 36.21; df 4; p = 0.001). However, 42% of bipolar depression cases were misclassified as being in manic phase.

CONCLUSIONS

The findings should be treated with caution as this was a small-scale pilot study and we did not control for prescribed treatments, medication adherence, etc. However, the insights gained should encourage more widespread adoption of statistical approaches to the classification of cases alongside the application of more sophisticated modelling of activity patterns. The difficulty of accurately classifying cases of bipolar depression requires further research, as it is unclear whether the lower prediction rate reflects weaknesses in a model based only on actigraphy data, or if it reflects clinical reality i.e. the possibility that there may be more than one subtype of bipolar depression.