Testing a clinical staging model for bipolar disorder using longitudinal life chart data

Bipolar disorder staging and the impact it has on its management: an update

INTRODUCTION

The longitudinal course of bipolar disorder (BD) is associated with an active process of neuroprogression, characterized by structural brain alterations and progressive functional impairment. In the last decades, a growing need of a standardized staging model for BD arose, with the aim of a more appropriate definition of stage-specific clinical manifestations and the identification of more customized therapeutic tools.

AREAS COVERED

The authors review the literature on clinical aspects, neurobiological correlates and treatment issues related to BD progression. Thereafter, they address the definition, constructs, and evolution of the staging concept, focusing on the clinical applications of BD staging models available in literature.

EXPERT OPINION

Although several staging models for BD have been proposed to date, their application in clinical practice is still relatively scant. This may have a detrimental impact on the clinical and therapeutic management of BD, in terms of early and proper diagnosis as well as tailored treatment interventions according to the different stages of illness. Future research efforts should tend to the integration of recent insights on neuroimaging and epigenetic markers, toward a standardized and multidimensional staging model.

Bipolar disorders and schizophrenia: discrete disorders?

Background

With similarities in heritability, neurobiology and symptomatology, the question has been raised whether schizophrenia and bipolar disorder are truly distinctive disorders or belong to a continuum. This narrative review summarizes common and distinctive findings from genetics, neuroimaging, cognition and clinical course that may help to solve this ethiopathogenetic puzzle.

Methods

The authors conducted a literature search for papers listed in PubMed and Google Scholar, using the search terms "schizophrenia" and "bipolar disorder" combined with different terms such as "genes", "neuroimaging studies", "phenomenology differences", "cognition", "epidemiology". Articles were considered for inclusion if they were written in English or Spanish, published as full articles, if they compared subjects with schizophrenia and bipolar disorder, or subjects with either disorder with healthy controls, addressing differences between groups.

Results

Several findings support the hypothesis that schizophrenia and bipolar disorder are discrete disorders, yet some overlapping of findings exists. The evidence for heritability of both SZ and BD is obvious, as well as the environmental impact on individual manifestations of both disorders. Neuroimaging studies support subtle differences between disorders, it appears to be rather a pattern of irregularities than an unequivocally unique finding distinguishing schizophrenia from bipolar disorder. The cognitive profile displays differences between disorders in certain domains, such as premorbid intellectual functioning and executive functions. Finally, the timing and trajectory of cognitive impairment in both disorders also differs.

Conclusion

The question whether SZ and BD belong to a continuum or are separate disorders remains a challenge for further research. Currently, our research tools may be not precise enough to carve out distinctive, unique and undisputable differences between SZ and BD, but current evidence favors separate disorders. Given that differences are subtle, a way to overcome diagnostic uncertainties in the future could be the application of artificial intelligence based on BigData.

Limitations

Despite the detailed search, this article is not a full and complete review of all available studies on the topic. The search and selection of papers was also limited to articles in English and Spanish. Selection of papers and conclusions may be biased by the personal view and clinical experience of the authors.

Accelerated brain aging as a biomarker for staging in bipolar disorder: an exploratory study

BACKGROUND

Two established staging models outline the longitudinal progression in bipolar disorder (BD) based on episode recurrence or inter-episodic functioning. However, underlying neurobiological mechanisms and corresponding biomarkers remain unexplored. This study aimed to investigate if global and (sub)cortical brain structures, along with brain-predicted age difference (brain-PAD) reflect illness progression as conceptualized in these staging models, potentially identifying brain-PAD as a biomarker for BD staging.

METHODS

In total, 199 subjects with bipolar-I-disorder and 226 control subjects from the Dutch Bipolar Cohort with a high-quality T1-weighted magnetic resonance imaging scan were analyzed. Global and (sub)cortical brain measures and brain-PAD (the difference between biological and chronological age) were estimated. Associations between individual brain measures and the stages of both staging models were explored.

RESULTS

A higher brain-PAD (higher biological age than chronological age) correlated with an increased likelihood of being in a higher stage of the inter-episodic functioning model, but not in the model based on number of mood episodes. However, after correcting for the confounding factors lithium-use and comorbid anxiety, the association lost significance. Global and (sub)cortical brain measures showed no significant association with the stages.

CONCLUSIONS

These results suggest that brain-PAD may be associated with illness progression as defined by impaired inter-episodic functioning. Nevertheless, the significance of this association changed after considering lithium-use and comorbid anxiety disorders. Further research is required to disentangle the intricate relationship between brain-PAD, illness stages, and lithium intake or anxiety disorders. This study provides a foundation for potentially using brain-PAD as a biomarker for illness progression.

Spanish validation of the Empirically Developed Clinical Staging Model (EmDe-5) for patients with bipolar disorder

INTRODUCTION

Bipolar disorder (BD) has been reconceptualised as a progressive disorder that develops from mild to severe presentations. An empirical staging model - the Empirically Developed Clinical Staging Model for BD (EmDe-5) - was developed in a previous study. This study aims to further validate that model using a larger and more representative Spanish sample.

MATERIAL AND METHODS

183 BD outpatients were recruited at 11 sites in Spain. Assessment included clinical characteristics of the BD (number of hospitalisations, number of suicide attempts, comorbid personality disorders), physical health (BMI, metabolic syndrome, number of physical illnesses), cognition (SCIP), functioning (permanently disabled due to BD, FAST), and quality of life (SF-36). The CGI-S, VAS-S, and psychopharmacological treatment pattern were used as external validators.

RESULTS

Ten patients (51.5%) were classified as stage 1, 33 (18%) as stage 2, 93 (508%) as stage 3, 37 (202%) as stage 4, and 10 (55%) as stage 5. All profilers, other than number of suicide attempts (p=0.311) and comorbid personality disorder (p=0.061), exhibited worse scores from stage 1 to 5. As expected, VAS-S and CGI-S scores were worse in the later stages. Regarding treatment, early stages (1-2) were associated with the use of one to three drugs while late stages (4-5) were associated with four or more drugs (p=0.002).

CONCLUSIONS

We confirm the EmDe-5 staging model's construct validity. The ease of obtaining the profilers, together with the operational criteria provided to quantify them, will facilitate the use of the EmDe-5 staging model in daily clinical practice.

Progressive grey matter alterations in bipolar disorder across the life span - A systematic review

OBJECTIVES

To elucidate the relationship between the course of bipolar disorder (BD) and structural brain changes across the life span, we conducted a systematic review of longitudinal imaging studies in adolescent and adult BD patients.

METHODS

Eleven studies with 329 BD patients and 277 controls met our PICOS criteria (participants, intervention, comparison, outcome and study design): BD diagnosis based on DSM criteria, natural course of disease, comparison of grey matter changes in BD individuals over ≥1-year interval between scans.

RESULTS

The selected studies yielded heterogeneous findings, partly due to varying patient characteristics, data acquisition and statistical models. Mood episodes were associated with greater grey matter loss in frontal brain regions over time. Brain volume decreased or remained stable in adolescent patients, whereas it increased in healthy adolescents. Adult BD patients showed increased cortical thinning and brain structural decline. In particular, disease onset in adolescence was associated with amygdala volume reduction, which was not reported in adult BD.

CONCLUSIONS

The evidence collected suggests that the progression of BD impairs adolescent brain development and accelerates structural brain decline across the lifespan. Age-specific changes in amygdala volume in adolescent BD suggest that reduced amygdala volume is a correlate of early onset BD. Clarifying the role of BD in brain development across the lifespan promises a deeper understanding of the progression of BD patients through different developmental episodes.

"Addressing the core trait of bipolar disorder": A concept analysis of mood-stabilizing drugs

OBJECTIVE

The term "mood stabilizer" is controversial in the literature and criticized for being imprecise and overly inclusive, having its retirement suggested to avoid misuse. Nevertheless, it continues to be employed as it may still carry important meaning.

METHODS

We employed document analysis for reviewing relevant definitions of mood stabilizer employed in the literature. Then, we clarify the meanings associated with the term by employing evolutionary concept analysis. Based on its results, we present a theoretical model for a mood stabilizer and further match it with evidence gathered from published meta-analyses and other sources for drugs used in the treatment of bipolar disorder.

RESULTS

Concept analysis unearthed four attributes of a mood stabilizer that were nested into the following ascending hierarchy: "not worsening," "acute effects," "prophylactic effects," and "advanced effects." "Prophylactic effects" were often considered the core aspect of a legitimate mood stabilizer.

CONCLUSION

The proposed model uses a hierarchy of attributes that take into account the complexity of the term and help to determine whether a drug is a mood stabilizer. Prophylaxis is pivotal to the concept, whose utility lies in implying a drug able to truly treat bipolar disorder, as opposed to merely targeting symptoms. Consistent use of the term could encourage investigation of drugs that modify long-term outcomes and illness trajectory, instead of simply approaching symptom clusters.

Staging models applied in a sample of patients with bipolar disorder: Results from a retrospective cohort study

BACKGROUND

Bipolar Disorder (BD) is a life-long illness with compelling evidence of progression. Although different staging models have been proposed to evaluate its course, clinical data remain limited. The aim of the present study was to retrospectively assess applicability of available staging approaches and their pattern of progression in a sample of bipolar patients.

METHODS

In a naturalistic sample of 100 BD patients, retrospective assessment of clinical stages was performed at four time points over 10 years, according to four staging models. Staging progression with potential associations between stages and unfavourable illness characteristics were analyzed.

RESULTS

A pattern of stage worsening emerged for each model, with a significant increase at every time point. Greater stage increases emerged in patients with lower educational level, age at first elevated episode ≤35 years, duration of illness ≤25 years, and duration of untreated illness ≤5 years. Lower stage values were associated with BD II, no psychiatric hospitalization, depressive onset and predominant polarity, ≤three lifetime episodes, age at first mood stabilizer >40 years, duration of illness ≤25 years, and engaged/employed status. Higher stage values were associated with lower age at first elevated episode and mood stabilizing treatment instead.

LIMITATIONS

Naturalistic and retrospective design, recruitment at a 2nd level specialistic clinic.

CONCLUSIONS

Reported findings support the progressive nature of BD and the application of staging models for early intervention, suggesting a conceptualization of a standardized approach to better characterize patients, predict their clinical course, and deliver tailored treatment options.

Heterogeneous early illness courses of Korean patients with bipolar disorders: replication of the staging model

BACKGROUND

Clinical staging of bipolar disorder (BD) requires application of real-world data, as the next step in hypothesis. This study used the staging model to analyze the long-term course of BD in Korean patients based on clinical features and treatment responses to map the progression of bipolar illness from its early phase after the onset of illness.

METHODS

A total of 136 patients diagnosed with BD-I (n = 62) or BD-II (n = 74) were recruited. Their progressive stages were retrospectively evaluated. A multi-state model was used to calculate the probability of progression to each stage. Hazard ratios of covariates expected to influence different courses of BD were calculated. Using the Alda score, long-term responses to mood stabilizers depending on the current stage were compared.

RESULTS

Several sub-populations showed varied courses during the first five years after the onset of illness, with 41.5% remaining in stage 2 and 53% progressing to higher stages with shortened time for transition. Profiles of patients with BD-I and BD-II were different, suggesting biologically distinct groups. Comorbid psychiatric disorders, such as obsessive-compulsive disorder (OCD) and bulimia nervosa (BN) were associated with a recurrent course (stage 3a or 3b) or a malignant course (stage 3c or 4). Early age of onset, shorter duration of illness, older age at the start of medication, and poor response to lithium affected the illness progression.

CONCLUSION

We were able to apply the stage model based on episode recurrence patterns in early illness courses of Korean patients with BD. The stage progression pattern differed from the early phase in BD-I and BD-II patients. Psychotic comorbidity, age at onset, age at starting psychiatric treatment showed associations with the illness progression.

Illness progression in older-age bipolar disorder: Exploring the applicability, dispersion, concordance, and associated clinical markers of two staging models for bipolar disorder in an older population

OBJECTIVES

The validity and applicability of two existing staging models reflecting illness progression have been studied in bipolar disorder (BD) in adults, but not in older adult populations. Staging model A is primarily defined by the number and recurrence of mood episodes, model B is defined by the level of inter-episodic functioning. This study aimed to explore the applicability, dispersion, and concordance of, and associations with clinical markers in these two staging models in older-age bipolar disorder (OABD).

METHODS

Using cross-sectional data from the Dutch Older Bipolars study, OABD outpatients (N = 126, ≥50 years) were staged using models A and B. Dispersion over the stages and concordance between the models were assessed. Associations were explored between model stages and clinical markers (familial loading, childhood abuse, illness duration, episode density, treatment resistance, Mini-Mental State Examination, and composite cognitive score).

RESULTS

Ninety subjects could be assigned to model A, 111 to model B, 80 cases to both. The majority (61%) had multiple relapses (model A, stage 3C) but were living independently (model B, stage I-III). Concordance between models was low. For model A, the markers childhood abuse, illness duration, and episode density significantly increased over subsequent stages. Model B was not associated with a significant change in any marker.

CONCLUSIONS

Assigning stages to OABD subjects was possible for both models, with age-related adjustments for model B. Model B as currently operationalized may be less suitable for OABD or may measure different aspects of illness progression, reflected by its low correspondence with model A and lack of associated clinical markers.

Clinical profiles of subsequent stages in bipolar disorder: Results from the Dutch Bipolar Cohort

INTRODUCTION

The manifestation of bipolar disorder (BD) is hypothesized to be determined by clinical characteristics such as familial loading, childhood abuse, age at onset, illness duration, comorbid psychiatric disorders, addiction, treatment resistance, and premorbid cognitive functioning. Which of these are associated with a more severe course and worse outcome is currently unknown. Our objective is to find a combination of clinical characteristics associated with advancement to subsequent stages in two clinical staging models for BD.

METHODS

Using cross-sectional data from the Dutch Bipolar Cohort, staging was applied to determine the progression of bipolar-I-disorder (BD-I; N = 1396). Model A is primarily defined by recurrence of mood episodes, ranging from prodromal to chronicity. Model B is defined by level of inter-episodic functioning, ranging from prodromal to inability to function autonomously. For both models, ordinal logistic regression was conducted to test which clinical characteristics are associated with subsequent stages.

RESULTS

For model A, familial loading, childhood abuse, earlier onset, longer illness duration, psychiatric comorbidity, and treatment resistance were all predictors for a higher stage in contrast to addiction and cognitive functioning. For model B, childhood abuse, psychiatric comorbidity, cognitive functioning, and treatment resistance were predictors for a more severe stage, whereas age at onset, illness duration, and addiction were not.

DISCUSSION/CONCLUSIONS

Differences in clinical characteristics across stages support the construct validity of both staging models. Characteristics associated with a higher stage largely overlapped across both models. This study is a first step toward determining different clinical profiles, with a corresponding course and outcome.

Bipolar disorder treatment according to illness trajectory: a systematic review of clinical trials

The current bipolar disorder treatment guidelines focus mainly on the prevention of recurrence and stabilization of acute mood episodes while neglecting outcomes related to the longitudinal course of illness. We systematically reviewed studies that assess the impact of disease progression in the treatment of patients with bipolar disorder. We searched PubMed, Embase, and Web of Science for clinical trials that moderated treatment effects by number of previous episodes, disease length, or a clinical staging model. We retrieved 6,156 potential abstracts. After deduplication, 5,376 were screened and eight studies met inclusion criteria. Seven trials moderated results by number of prior episodes, and one of those also used a measure of disease length. One trial used a clinical staging model and yielded informing results. Only three studies evaluated pharmacological interventions, the other five assessing psychotherapeutic modalities. Most of the studies were post-hoc analysis of clinical trials not primarily aimed at studying variables associated with illness trajectory. Overall, a loss of efficacy was found according to clinical progression, which supports early intervention. Tailored recommendations according to disease stages cannot be made. Furthermore, we identified methodological weaknesses and strengths in this subfield of research, suggesting the use of clinical staging models for future studies.

Socioeconomic and substance use changes in emerging adults and their relationship with mood disorders in a population-based cohort

In this report, we aim to assess the interaction of bipolar disorder and major depressive disorder with the evolution of social roles, economic classification, and substance misuse in emerging adults. This is a longitudinal population-based study (n = 231 at baseline), in which participants were reassessed at a mean of 5 years after baseline. A structured clinical interview was used to diagnose the participants with bipolar disorder and major depression; a control group without mood disorders was included. Men with mood disorders were less likely to be married in the beginning of the study and less likely to work in the follow-up. Women with major depression were less likely to study and more likely to be in a lower economic class at the beginning of the study. In comparison, women with bipolar disorder were less likely to live with their parents and more likely to live with their children in the first wave of the study. Substance misuse was more likely in people with mood disorders, especially in men, and women with bipolar disorder had the highest likelihood in the follow-up. Albeit longitudinal analyses were limited by a possibly insufficient sample size and mediating mechanisms for change, such as stigma, were not explored, the study suggests sex-related specificities regarding the change in social roles and substance use in people with mood disorders. Emerging adults, especially those with mood disorders, are in a period of change and instability and at a greater risk for substance use and abuse.

Early illness progression in mood disorders: A population-based longitudinal study

This study is aimed at assessing changes in functioning among young people from the general population with bipolar disorder and major depressive disorder over a period of five years. Specifically, we hypothesized that significant illness progression would take place during euthymia over time in bipolar disorder. We conducted a longitudinal study with 231 people, assessed at baseline and again at a five-year follow-up. A structured clinical interview was used to diagnose participants with mood disorders. A control group without mood disorders was also included. Functioning was assessed with the Functioning Assessment Short Test, and linear mixed models were used to analyze the effect of psychopathology on change in functioning. Mood disorders were associated with significant functional impairment, but functioning significantly improved in both groups over the 5-year follow-up period. Depressive episodes, however, were associated with worse functioning at follow-up, independently of depression severity. In contrast to our initial hypothesis, we found a worsening of functioning in a five-year period associated only with depressive episodes. This suggests that interventions focused on the prevention of mood episodes early in the course of illness may be particularly promising to reduce adverse functioning outcomes.

Consensus on nomenclature for clinical staging models in bipolar disorder: A narrative review from the International Society for Bipolar Disorders (ISBD) Staging Task Force

OBJECTIVES

Clinical staging is widely used in medicine to map disease progression, inform prognosis, and guide treatment decisions; in psychiatry, however, staging remains a hypothetical construct. To facilitate future research in bipolar disorders (BD), a well-defined nomenclature is needed, especially since diagnosis is often imprecise with blurred boundaries, and a full understanding of pathophysiology is lacking.

METHODS

Under the auspices of the International Society of Bipolar Disorders, a Task Force of international experts was convened to review, discuss, and integrate findings from the scientific literature relevant to the development of a consensus staging model and standardize a terminology that could be used to advance future research including staging of BD and related disorders.

RESULTS

Consensus opinion and areas of uncertainty or difference were identified in regard to terms referring to staging as it may apply to BD, to at-risk status and subthreshold stages, and to various clinical stages of BD as it is currently diagnosed.

CONCLUSION

The use of a standardized nomenclature about the clinical stages of BD will facilitate communication about research on clinical and pathological components of this heterogeneous group of disorders. The concepts presented are based on current evidence, but the template provided allows for further refinements as etiological advances come to light.

Causes and Consequences of Diagnostic Heterogeneity in Depression: Paths to Discovering Novel Biological Depression Subtypes

Depression is a highly heterogeneous syndrome that bears only modest correlations with its biological substrates, motivating a renewed interest in rethinking our approach to diagnosing depression for research purposes and new efforts to discover subtypes of depression anchored in biology. Here, we review the major causes of diagnostic heterogeneity in depression, with consideration of both clinical symptoms and behaviors (symptomatology and trajectory of depressive episodes) and biology (genetics and sexually dimorphic factors). Next, we discuss the promise of using data-driven strategies to discover novel subtypes of depression based on functional neuroimaging measures, including dimensional, categorical, and hybrid approaches to parsing diagnostic heterogeneity and understanding its biological basis. The merits of using resting-state functional magnetic resonance imaging functional connectivity techniques for subtyping are considered along with a set of technical challenges and potential solutions. We conclude by identifying promising future directions for defining neurobiologically informed depression subtypes and leveraging them in the future for predicting treatment outcomes and informing clinical decision making.

Depression Preceding Diagnosis of Bipolar Disorder

This paper focuses on depression that precedes an onset of manifest bipolar disorder as early stage bipolar disorder. First, we review how to pragmatically identify the clinical characteristics of patients presenting with an episode of depression who subsequently go on to develop episodes of mania or hypomania. The existing literature shows a strong consensus: accurate identification of depression with early onset and recurrent course with multiple episodes, subthreshold hypomanic and/or mixed symptoms, and family history of bipolar disorder or completed suicide have been shown by multiple authors as signs pointing to bipolar diagnosis. This contrasts with relatively limited information available to guide management of such "pre-bipolar" (pre-declared bipolar) patients, especially those in the adult age range. Default assumption of unipolar depression at this stage carries significant risk. Antidepressants are still the most common pharmacological treatment used, but clinicians need to be aware of their potential harm. In some patients with unrecognized bipolar depression, antidepressants can not only produce switch to (hypo)mania, but also mixed symptoms, or worsening of depression with an increased risk of suicide. We review pragmatic management strategies in the literature beyond clinical guidelines that can be considered for this at-risk group encompassing the more recent child and adolescent literature. In the future, genetic research could make the early identification of bipolar depression easier by generating informative markers and polygenic risk scores.

Toward Circuit Mechanisms of Pathophysiology in Depression

The search for more effective treatments for depression is a long-standing primary objective in both psychiatry and translational neuroscience. From initial models centered on neurochemical deficits, such as the monoamine hypothesis, research toward this goal has shifted toward a focus on network and circuit models to explain how key nodes in the limbic system and beyond interact to produce persistent shifts in affective states. To build these models, researchers have turned to two complementary approaches: neuroimaging studies in human patients (and their healthy counterparts) and neurophysiology studies in animal models, facilitated in large part by optogenetic and chemogenetic techniques. As the authors discuss, functional neuroimaging studies in humans have included largely task-oriented experiments, which have identified brain regions differentially activated during processing of affective stimuli, and resting-state functional MRI experiments, which have identified brain-wide networks altered in depressive states. Future work in this area will build on a multisite approach, assembling large data sets across diverse populations, and will also leverage the statistical power afforded by longitudinal imaging studies in patient samples. Translational studies in rodents have used optogenetic and chemogenetic tools to identify not just nodes but also connections within the networks of the limbic system that are both critical and permissive for the expression of motivated behavior and affective phenotypes. Future studies in this area will exploit mesoscale imaging and multisite electrophysiology recordings to construct network models with cell-type specificity and high statistical power, identifying candidate circuit and molecular pathways for therapeutic intervention.

The CINP Guidelines on the Definition and Evidence-Based Interventions for Treatment-Resistant Bipolar Disorder

BACKGROUND

Resistant bipolar disorder is a major mental health problem related to significant disability and overall cost. The aim of the current study was to perform a systematic review of the literature concerning (1) the definition of treatment resistance in bipolar disorder, (2) its clinical and (3) neurobiological correlates, and (4) the evidence-based treatment options for treatment-resistant bipolar disorder and for eventually developing guidelines for the treatment of this condition.

MATERIALS AND METHODS

The PRISMA method was used to identify all published papers relevant to the definition of treatment resistance in bipolar disorder and the associated evidence-based treatment options. The MEDLINE was searched to April 22, 2018.

RESULTS

Criteria were developed for the identification of resistance in bipolar disorder concerning all phases. The search of the literature identified all published studies concerning treatment options. The data were classified according to strength, and separate guidelines regarding resistant acute mania, acute bipolar depression, and the maintenance phase were developed.

DISCUSSION

The definition of resistance in bipolar disorder is by itself difficult due to the complexity of the clinical picture, course, and treatment options. The current guidelines are the first, to our knowledge, developed specifically for the treatment of resistant bipolar disorder patients, and they also include an operationalized definition of treatment resistance. They were based on a thorough and deep search of the literature and utilize as much as possible an evidence-based approach.

Exploring the clinical utility of two staging models for bipolar disorder

OBJECTIVE

To assess the clinical utility of two staging models for bipolar disorder by examining distribution, correlation, and the relationship to external criteria. These are primarily defined by the recurrence of mood episodes (model A), or by intra-episodic functioning (model B).

METHODS

In the Dutch Bipolar Cohort, stages according to models A and B were assigned to all patients with bipolar-I-disorder (BD-I; N = 1396). The dispersion of subjects over the stages was assessed and the association between the two models calculated. For both models, change in several clinical markers were concordant with the stage was investigated.

RESULTS

Staging was possible in 87% of subjects for model A and 75% for model B. For model A, 1079 participants (93%) were assigned to stage 3c (recurrent episodes). Subdividing stage 3c with cut-offs at 5 and 10 episodes resulted in subgroups containing 242, 510, and 327 subjects. For model B, most participants were assigned to stage II (intra-episodic symptoms, N = 431 (41%)) or stage III (inability to work, N = 451 (43%)). A low association between models was found. For both models, the clinical markers "age at onset," "treatment resistance," and "episode acceleration" changed concordant with the stages.

CONCLUSION

The majority of patients with BD-I clustered in recurrent stage 3 of Model A. Model B showed a larger dispersion. The stepwise change in several clinical markers supports the construct validity of both models. Combining the two staging models and sub-differentiating the recurrent stage into categories with cut-offs at 5 and 10 lifetime episodes improves the clinical utility of staging for individual patients.

A clinical staging model for bipolar disorder: longitudinal approach

Bipolar disorder (BD) has been identified as a life-course illness with different clinical manifestations from an at-risk to a late stage, supporting the assumption that it would benefit from a staging model. In a previous study, we used a clustering approach to stratify 224 patients with a diagnosis of BD into five clusters based on clinical characteristics, functioning, cognition, general health, and health-related quality of life. This study was design to test the construct validity of our previously developed k-means clustering model and to confirm its longitudinal validity over a span of 3 years. Of the 224 patients included at baseline who were used to develop our model, 129 (57.6%) reached the 3-year follow-up. All life domains except mental health-related quality of life (QoL) showed significant worsening in stages (p < 0.001), suggesting construct validity. Furthermore, as patients progressed through stages, functional decline (p < 0.001) and more complex treatment patterns (p = 0.002) were observed. As expected, at 3 years, the majority of patients remained at the same stage (49.6%), or progressed (20.9%) or regressed (23.3%) one stage. Furthermore, 85% of patients who stayed euthymic during that period remained at the same stage or regressed to previous stages, supporting its longitudinal validity. For that reason, this study provides evidence of the construct and longitudinal validity of an empirically developed, comprehensive staging model for patients with BD. Thus, it may help clinicians and researchers to better understand the disorder and, at the same time, to design more accurate and personalized treatment plans.

The Impact of Subsyndromal Bipolar Symptoms on Patient's Functionality and Quality of Life

Subsyndromal symptoms have rarely been in the focus of bipolar research. This may be, in part, due to the fact that there is neither a uniform definition nor do they constitute an indication of regulatory and commercial interest. Nevertheless, they do have a decisive impact on the long-term course of bipolar disorder (BD), and the degree of functionality and quality of life (QoL) is more likely determined by their presence or absence than by acute episodes. Summarizing the literature an estimated 20-50% of patients suffer inter-episodically or chronically from subsyndromal BD. The most prominent symptoms that interfere with functionality are subsyndromal depression, disturbances of sleep, and perceived cognitive impairment, whereas anxiety negatively impacts on QoL. In the absence of evidence-based pharmacological treatments for subsyndromal BD, clinical practice adopts guidelines designed for treatment-resistant full-blown episodes of BD, supplemented by cognitive-behavioral, family focused or social-rhythm-based psychotherapies.

Testing a clinical staging model for bipolar disorder using longitudinal life chart data

OBJECTIVE

Bipolar disorder has a wide range of clinical manifestations which may progress over time. The aim of this study was to test the applicability of a clinical staging model for bipolar disorder and to gain insight into the nature of the variables influencing progression through consecutive stages.

METHODS

Using retrospectively reported longitudinal life chart data of 99 subjects from the Stanley Foundation Bipolar Network Naturalistic Follow-up Study, the occurrence, duration and timely sequence of stages 2-4 were determined per month. A multi-state model was used to calculate progression rates and identify determinants of illness progression. Stages 0, 1 and several other variables were added to the multi-state model to determine their influence on the progression rates.

RESULTS

Five years after onset of BD (stage 2), 72% reached stage 3 (recurrent episodes) and 21% had reached stage 4 (continuous episodes), of whom 8% recovered back to stage 3. The progression from stage 2 to 3 was increased by a biphasic onset for both the depression-mania and the mania-depression course and by male sex.

CONCLUSIONS

Staging is a useful model to determine illness progression in longitudinal life chart data. Variables influencing transition rates were successfully identified.