Understanding Of Bipolar Disorder Research Articles

Role of the Cerebellum in Bipolar Disorder: A Systematic Literature Review.

The aim of this systematic literature review was to investigate the role of the cerebellum in the affective symptoms observed in patients with bipolar disorder. The present systematic literature review included clinical studies conducted from 2013-2023 among adult populations with bipolar I and II disorders, along with their specifiers. With regard to cerebellar pathology, it was found that those with bipolar disorder performed worse than their healthy counterparts in their ability to comprehend the mental states of others and in identifying negative mental states. Additionally, individuals with bipolar disorder had reduced gray matter loss in regions such as lobules I-IX, crus I, and crus II, different functional activation patterns of the thalamus, striatum, and hippocampus on functional magnetic resonance imaging (fMRI), and increased cortical thickness. Cerebro-cerebellar functional connectivities were altered in patients with bipolar disorder. The effects of lamotrigine and lithium on cerebellar volume and abnormalities are also discussed in this paper. The present systematic literature review illustrates the emerging involvement of the cerebellum in bipolar disorder and its affective symptoms and paves the way for future research and a better understanding of bipolar disorder.

Clinical correlates of late-onset versus early-onset bipolar disorder in a global sample of older adults.

Late-onset bipolar disorder (LOBD) represents a significant subgroup of bipolar disorder (BD). However, knowledge for this group is mostly extrapolated from small studies in subjects with early/mixed age of illness onset. In this global sample of older adults with BD (OABD: ≥50years old) we aim to characterize the sociodemographic and clinical presentation of LOBD (≥40years at BD onset) compared to early-onset BD (EOBD: <40years at BD onset). The Global Aging and Geriatric Experiments in Bipolar Disorder consortium provided international data on 437 older age bipolar disorder participants. We compared LOBD versus EOBD on depression, mania, functionality, and physical comorbidities. Exploratory analyses were performed on participants with BD onset ≥50years old. LOBD (n=105) did not differ from EOBD (n=332) on depression, mania, global functioning, nor employment status (p>0.05). Late-onset bipolar disorder was associated with higher endocrine comorbidities (odds ratio=1.48, [95%CI=1.0,12.1], p=0.03). This difference did not remain significant when subjects with BD onset ≥50years old were analyzed. This study is limited by the retrospective nature of the variable age of onset and the differences in evaluation methods across studies (partially overcame by harmonization processes). The present analysis is in favor of the hypothesis that LOBD might represent a similar clinical phenotype as classic EOBD with respect to core BD symptomatology, functionality, and comorbid physical conditions. Large-scale global collaboration to improve our understanding of BD across the lifespan is needed.

The dynamic interplay between sleep and mood: an intensive longitudinal study of individuals with bipolar disorder.

Sleep disturbances are important symptoms to monitor in people with bipolar disorder (BD) but the precise longitudinal relationships between sleep and mood remain unclear. We aimed to examine associations between stable and dynamic aspects of sleep and mood in people with BD, and assess individual differences in the strength of these associations. Participants (N = 649) with BD-I (N = 400) and BD-II (N = 249) provided weekly self-reports of insomnia, depression and (hypo)mania symptoms using the True Colours online monitoring tool for 21 months. Dynamic structural equation models were used to examine the interplay between weekly reports of insomnia and mood. The effects of clinical and demographic characteristics on associations were also assessed. Increased variability in insomnia symptoms was associated with increased mood variability. In the sample as a whole, we found strong evidence of bidirectional relationships between insomnia and depressive symptoms but only weak support for bidirectional relationships between insomnia and (hypo)manic symptoms. We found substantial variability between participants in the strength of prospective associations between insomnia and mood, which depended on age, gender, bipolar subtype, and a history of rapid cycling. Our results highlight the importance of monitoring sleep in people with BD. However, researchers and clinicians investigating the association between sleep and mood should consider subgroup differences in this relationship. Advances in digital technology mean that intensive longitudinal data on sleep and mood are becoming increasingly available. Novel methods to analyse these data present an exciting opportunity for furthering our understanding of BD.

The genetics of bipolar disorder.

Bipolar disorder (BD) is one of the most heritable mental illnesses, but the elucidation of its genetic basis has proven to be a very challenging endeavor. Genome-Wide Association Studies (GWAS) have transformed our understanding of BD, providing the first reproducible evidence of specific genetic markers and a highly polygenic architecture that overlaps with that of schizophrenia, major depression, and other disorders. Individual GWAS markers appear to confer little risk, but common variants together account for about 25% of the heritability of BD. A few higher-risk associations have also been identified, such as a rare copy number variant on chromosome 16p11.2. Large scale next-generation sequencing studies are actively searching for other alleles that confer substantial risk. As our understanding of the genetics of BD improves, there is growing optimism that some clear biological pathways will emerge, providing a basis for future studies aimed at molecular diagnosis and novel therapeutics.

The concept of temperament and its contribution to the understanding of the bipolar spectrum

The present article attempts first to provide a historical overview of the concept of temperament,The present article attempts first to provide a historical overview of the concept of temperament,since its foundation by Polybos (4th century B.C.) and the school of Cos, its predominant role in theshaping of the anthropological and humanitarian sciences, until the modern theoretical formulations,such as those proposed by Robert Cloninger and Hagop Akiskal. Secondly, recent literature ispresented, which suggests a strong link of different temperament structures to mental health andpsychopathology. Hans Eysenck (1916-1997) was the first psychologist to establish approaches topersonality differences and to distinguish three dimensions of personality: Neuroticism, Extraversionand Psychotisism. Eysenck was followed by McCrae and Costa who proposed that there are five basicdimensions of personality ("Big Five"). In the mid-1980s, Robert Cloninger developed a distinctivedimensional model of temperament and character traits. Hagop Akiskal emphasized on the affectivecomponents of temperament and their possible connections to mood disorders and creativity.Specifically, temperament assessment seems to help in differentiating between the relationship ofvarious temperaments and the clinical manifestations of bipolar illness. Within the area of mood disorders,specific affective temperaments might constitute vulnerability factors, as well as clinical pictureand illness course modifiers. Viewing mood disorders under this prism gives birth to the concept ofthe bipolar spectrum with major implications for all aspects of mental health research and providingof care. The hyperthymic and the depressive temperaments are related to the more 'classic' bipolarpicture (that is euphoria, grandiose and paranoid thinking, antisocial behavior, psychomotor accelerationand reduced sleep and depressive episodes respectively). On the contrary cyclothymic, anxiousand irritable temperaments are related to more complex pictures and might predict poor responseto treatment, violent or suicidal behavior and high comorbidity. Unipolar disorder diagnosis is oftenchanged due to the fact that a manic or mixed episode can occur after several years of treatment failure.In these cases the evaluation of temperament can prove to be effective in distinguishing betweenunipolar and bipolar depression and thus favoring treatment planning. In addition, temperament assessmentchanges the definition of bipolarity by supporting the concept of "bipolar spectrum". This isa factor that can lead to a rise in prevalence of bipolar cases. Furthermore, the evaluation of temperamenthas shifted our understanding of bipolarity towards the concept of the 'bipolar spectrum'. It hasalso led to an increase in the prevalence of bipolar disorder cases, notably bipolar II, and a decrease in unipolar cases. Finally, incorporating the concept of temperament in our understanding of bipolardisorder constitutes a challenging issue, which can lead to better treatment and outcome of patients.

Facial emotion recognition in childhood-onset bipolar I disorder: an evaluation of developmental differences between youths and adults.

Bipolar disorder (BD) is a severe mental illness with high healthcare costs and poor outcomes. Increasing numbers of youths are diagnosed with BD, and many adults with BD report that their symptoms started in childhood, suggesting that BD can be a developmental disorder. Studies advancing our understanding of BD have shown alterations in facial emotion recognition both in children and adults with BD compared to healthy comparison (HC) participants, but none have evaluated the development of these deficits. To address this, we examined the effect of age on facial emotion recognition in a sample that included children and adults with confirmed childhood-onset type-I BD, with the adults having been diagnosed and followed since childhood by the Course and Outcome in Bipolar Youth study. Using the Diagnostic Analysis of Non-Verbal Accuracy, we compared facial emotion recognition errors among participants with BD (n=66; ages 7-26years) and HC participants (n=87; ages 7-25years). Complementary analyses investigated errors for child and adult faces. A significant diagnosis-by-age interaction indicated that younger BD participants performed worse than expected relative to HC participants their own age. The deficits occurred both for child and adult faces and were particularly strong for angry child faces, which were most often mistaken as sad. Our results were not influenced by medications, comorbidities/substance use, or mood state/global functioning. Younger individuals with BD are worse than their peers at this important social skill. This deficit may be an important developmentally salient treatment target - that is, for cognitive remediation to improve BD youths' emotion recognition abilities.

La terapia cognitivo conductual en el tratamiento de la depresión del trastorno bipolar tipo I

A pesar de la farmacoterapia, tratamiento esencial del trastorno bipolar I, un porcentaje importante de pacientes experimenta nuevos episodios afectivos. La terapia cognitivo conductual (TCC), la psicoterapia interpersonal y ritmo social y la terapia familiar focalizada, lo mismo que la psicoeducación, enfoques psicosociales útiles en el tratamiento del trastorno bipolar, comparten el énfasis en el empoderamiento del paciente para convertirlo en participante activo de su tratamiento. La adición de la TCC al tratamiento tiene como objetivos aliviar los síntomas depresivos, restablecer el funcionamiento psicosocial y prevenir la aparición de nuevos episodios afectivos. Aunque la investigación es limitada, en este trabajo se describen las bases teóricas y los estudios empíricos que avalan el uso de la TCC como una intervención psicosocial indispensable. Objetivos. El presente trabajo tuvo como objetivo demostrar la utilidad de la TCC como tratamiento coadyuvante en la depresión del trastorno bipolar I para los síntomas residuales, la adherencia y el cumplimiento del tratamiento, la conciencia y la comprensión del trastorno bipolar, la identificación temprana de los síntomas de los episodios afectivos y el desarrollo de habilidades de afrontamiento. Método. Se revisaron los ensayos clínicos controlados acerca de la utilidad de la TCC como tratamiento del paciente con depresión del trastorno bipolar I. Resultados. La TCC aumenta la adherencia al tratamiento farmacológico, disminuye la frecuencia de recaídas en el primer año, los síntomas depresivos residuales, las hospitalizaciones y la duración de los episodios y mejora la adherencia terapéutica y el funcionamiento psicosocial; su utilidad es similar a la terapia familiar focalizada y la psicoterapia interpersonal y ritmo social. Los efectos terapéuticos disminuyen a lo largo del tiempo y sus resultados son menores en pacientes con mayor número de episodios afectivos (&gt;12) y mayor comorbilidad. Conclusiones. La TCC es una intervención que mejora la evolución del trastorno bipolar tipo I.

Multiplex immunoassay analysis of plasma shows prominent upregulation of growth factor activity pathways linked to GSK3β signaling in bipolar patients

BackgroundOur understanding of bipolar disorder (BD) aetiology has advanced in recent years but our ability to translate this to improve patient care in the clinic is still limited. MethodsIn this study, we have measured the concentrations of 190 different molecules using sensitive multiplex immunoassays in plasma of 17 BD patients compared to 46 matched control subjects. ResultsThe analyses led to the identification of 26 dysregulated proteins in BD patients compared to controls. These molecules were comprised mostly of growth factors, hormones, lipid transport and inflammatory proteins. Decreased apolipoprotein A1 has previously been associated with BD patients and this was confirmed in our study. LimitationsThe present pilot study was limited by its small sample size, use of multiple drug treatments and the lack of dietary restrictions at the time of sampling. ConclusionsFuture studies may increase our understanding of BD which will help to pave the way for much-needed patient stratification for better treatment outcomes.

The contingent negative variation in remitted paediatric bipolar patients: no evidence of abnormality.

Although the Contingent Negative Variation (CNV) paradigm has been useful in schizophrenia, limited research involving such paradigm in subjects with Bipolar Disorder (BD) has produced contradictory findings. To the best of our knowledge, no study has investigated CNV in Paediatric Bipolar Disorder (PBD) subjects. Thirty remitted PBD patients and thirty matched healthy control group subjects participated in the study. No significant between group main effect could be found for either CNV latency or amplitude. We propose that CNV is unlikely to be a true endophenotype of BD. However, absence of CNV finding during euthymic phase in BD may help us in advancing our understanding of BD and such finding may, in fact, have some specificity with regard to differentiating BD from schizophrenia.

Coming together: Evaluating the efficacy of group psychoeducation for people diagnosed with bipolar disorder

This paper aims to examine the effectiveness of a pilot psychoeducational group for people diagnosed with bipolar disorder. The group hoped to increase member’s understanding of Bipolar Disorder and develop coping mechanisms. Client feedback reflected increased control over their experiences and benefits from meeting other group members.

Les aspects culturels du trouble bipolaire : résultats d’une étude comparative entre des patients français et tunisiens

Bipolar disorders are one of the most potentially severe psychiatric disorders, implying a high degree of morbidity and incapacity for patients. Indeed, the World Health Organization in 1996 ranked them as the sixth most disabling condition worldwide. Major advances have been achieved in their understanding and management. However, too many patients do not yet benefit from them. As a matter of fact, bipolar disorders are still underestimated and under-recognized, being too often misdiagnosed with major depression or schizophrenia; the DSM-IV acknowledges the trend of clinicians to overdiagnose schizophrenia (rather than bipolar disorder), especially in ethnic groups and young people. Indeed, cultural factors may impact the symptomatology and the course of the disease. In particular, it has been shown by many authors that schizophrenia-like features are more likely to be found in southern countries. Similarly, the same authors have reported more manic than depressive episodes during the course of bipolar disorder. We aimed at comparing individuals with bipolar disorder living in two distinct geographic and cultural environments, namely France and Tunisia. Our study included two samples of 40 patients each, natives from the country, who were admitted during 2007 to the hospitals of Razi (Tunis, Tunisia) and Le Vinatier (Lyon, France) and suffering from a bipolar disorder according to the DSM-IV criteria. The French sample was constituted by all the patients meeting the inclusion criteria and the Tunisian one was selected by matching the patients by gender and duration of the disorder. Our results were consistent with the existing literature, showing many similarities and some marked differences such as a greater rate of manic episodes in the onset and during the course of the illness as well. The main result was the type of the first episode: mania in three quarter cases in Tunisia and depressive in the same proportion in France. The same figures applied to the recurrences. Unipolar mania, in particular, was three times more common in Tunisia than in France. Beyond the methodological biases (in-patients recruitment, diagnosis habits, cultural tolerance), these differences are also probably linked to climatic factors, such as temperature and photoperiod. The early detection of bipolar disorder is of crucial importance to provide specific treatments to patients. In a world where psychiatrists are more and more exposed to meet patients from various backgrounds, it is necessary to be aware of culture-bound features. Besides, the primacy of mania, in southern countries, may be a key to deepen our understanding of bipolar disorder and consequently its management.

Psychosocial research on the course of bipolar disorder: Appreciating its past and encouraging its future.

Miklowitz and Johnson (2009) review the accumulating accomplishments of studies of psychosocial contributors to and treatments of bipolar disorder. Much of the initial work was influenced by paradigms that addressed predictors and treatments of unipolar depression. That personality, stress, and family factors also play an important role in the course and outcomes of bipolar disorders has now been well established, but because depression appears to be especially debilitating and difficult to manage in bipolar disorder, further challenges remain to understand and treat it. At the same time the predictors of mania, and switching/cycling mechanisms, require further conceptualization and study, with a fruitful emphasis on the behavioral activation/reward dependence systems emerging in recent research. Cutting across all manifestations of the bipolar disorder is the need for additional study of mechanisms by which stressful experiences (acute, chronic, early adversity, and the family context) have adverse effects on mood regulation and the pathophysiology of bipolar disorder. Future growth in our understanding of bipolar disorder and its treatment will increasingly require integrative, multivariate, and longitudinal research. Clinical psychology has much to contribute to the conceptualization, methodology, and design of the new generation of research on the psychosocial aspects of bipolar disorder's course and treatment.

Neuropsychological impairment and psychosis in mania

Deficits involving executive function, working memory, speed of information processing, and new learning occur in many people with mania. Factors that predict impairment remain poorly understood, but there are indications that psychotic features may correspond with increased risk of neurocognitive dysfunction during manic episodes. The current study examined neuropsychological function in 40 inpatients with bipolar I mania, 24 of whom presented with psychotic features. Compared to a control group, the inpatients showed worse executive function, speed of information processing, new learning, and dexterity. Nonetheless, presence of psychotic features failed to distinguish the inpatients with mania. Thus, psychotic features do not appear to increase neurobehavioral morbidity in people with mania, but presence of mania clearly corresponded with neurobehavioral dysfunction. Implications of these data for clinical practice and our understanding of bipolar disorder are discussed.

Clinical and prognostic implications of seasonal pattern in bipolar disorder: a 10-year follow-up of 302 patients

More than 20% of bipolar patients may present with seasonal pattern (SP). Seasonality can alter the course of bipolar disorder. However, to date, long-term follow-up studies of bipolar patients presenting with SP are scarce. We present a 10-year follow-up study comparing clinical and demographic features of bipolar patients with and without SP. Three hundred and twenty-five bipolar I and II patients were followed up for at least 10 years. SP was defined according to DSM-IV criteria. Clinical variables were obtained from structured interviews with the patients and their relatives. Patients with and without SP were compared regarding clinical and sociodemographic variables and a stepwise logistic regression was performed. Seventy-seven patients (25.5%) were classified as presenting with SP, while 225 (74.5%) were considered as presenting with no significant seasonal variation. Twenty-three patients (7%) were excluded from the study because it was unclear whether they had seasonality or not. There were no differences between groups regarding demographic variables. Patients with SP predominantly presented with bipolar II disorder, depressive onset, and depressive predominant polarity. The greater burden of depression did not correlate with indirect indicators of severity, such as suicidality, hospitalizations or psychotic symptoms. Our study links the presence of SP with both bipolar II disorder and predominant depressive component. However, we could not find any difference regarding functionality or hospitalization rates. Modifications in the criteria to define SP are suggested for a better understanding of bipolar disorder.

Bipolar Disorder Clinical Synthesis: Where Does the Evidence Lead?

Bipolar disorder is a common condition diagnosed by the occurrence of pathological mood elevation but most often dominated by dysphoria states. Over the past 10 years, understanding of bipolar disorder and the number of evidence-based treatments have increased dramatically. This article offers strategies for improving diagnostic confidence and simple benchmarks that facilitate integrating principles of evidence-based medicine into the management of patients with bipolar disorder. Simple systematic assessment techniques such as focusing the evaluation to assess the most extreme episode of mood elevation and longitudinal factors such as age of onset and course of illness can avoid errors of omission and raise diagnostic confidence. An iterative measurement-based treatment model that aims to bring patients and their supports into the collaborative care process for progressively better outcomes is recommended.

An evaluation of social and adaptive skills in adults with bipolar disorder and severe/profound intellectual disability

The purpose of this study was to explore the interrelationship of social and adaptive skills in adults with bipolar disorder and severe or profound intellectual disability. A bipolar group ( N = 14), a severe psychopathology group without bipolar disorder ( N = 14), and a control group with no DSM-IV Axis I diagnosis ( N = 14) were compared on the Vineland Adaptive Behavior Scale (VABS) and the Matson Evaluation of Social Skills for Individuals with sEvere Retardation (MESSIER). Bipolar patients had significantly more negative verbal social skills than the other two groups on the MESSIER, but no group differences on the VABS were noted. The implications of these data are discussed for a better understanding of bipolar disorder in persons with intellectual disability.

Translating knowledge of genetics and pharmacology into improving everyday practice

Bipolar disorder is associated with significant morbidity and mortality; however, many aspects of this disorder remain poorly understood. It is likely that rapid advances in molecular genetics and neuroimaging will play a major role in advancing our understanding of bipolar disorder in future. Molecular genetics studies have already identified some candidate genes; for example, the BDNF, G72 and XBP1 genes, and chromosomal 'hot spots', which may confer a predisposition to development of bipolar disorder. Such advances may facilitate earlier, easier and more accurate diagnosis and provide novel targets for the treatment of this condition. Brain imaging studies using positron emission tomography and single photon emission computed tomography have shown that reduction in brain 5-hydroxytryptamine type 2 (5-HT(2)) receptors may be associated with prevention of or relief from depressive symptoms. Similarly, other imaging studies suggest that increased dopamine levels in the synapse mediate the symptoms of bipolar mania and that reduction in dopamine transmission through reduction in dopamine synthesis or blockade of dopamine D(2) receptors may be associated with antimanic effects. The ability of atypical antipsychotics to block both 5-HT(2) and D(2) receptors and downregulate 5-HT(2) receptors may explain how these drugs treat both the depressive and manic symptoms of bipolar disorder. Although molecular genetics and imaging techniques are not yet used as clinical tools for bipolar disorder, they provide valuable data to improve the understanding of the pathophysiology of bipolar disorder and should lead to new treatments and potentially episode prevention.

GAMIAN-Europe/BEAM survey I--global analysis of a patient questionnaire circulated to 3450 members of 12 European advocacy groups operating in the field of mood disorders.

GAMIAN-Europe is a pan-European federation of national patient organizations from 30 European countries covering the whole spectrum of psychiatry. To gain a better understanding of what it is like to live with bipolar disorder (BD), GAMIAN-Europe undertook a detailed patient-based questionnaire, known as 'GAMIAN-Europe/BEAM Survey', examining a variety of aspects. The questionnaire was mailed to 3450 patients from 12 member organizations in 11 countries. A total of 1760 completed questionnaires were received but 28 were ruled out as inappropriate. Of the remainder, 1041 respondents stated that they had been, or were, suffering from BD. The remainder stated that they were suffering from depression, dysthymia or atypical depression. The findings indicate that, on average, a bipolar patient is expected to wait for 5.7 years for a correct diagnosis from the first onset of symptoms. Many patients have a family history of mood and anxiety disorders. They experience a high degree of stigmatization from all quarters. This is reflected in the difficulties they experience in obtaining employment despite high academic achievement. Most patients receive combination therapy. Compliance problems resulting from adverse side-effects are less significant than in the past. Overall, the level of satisfaction with pharmacotherapy was high yet, paradoxically, patients had reservations about dependency issues and possible long-term side-effects. There was a clear need for more patient education about pharmacological and psychosocial interventions, despite material progress having been made over the past decade. There is an urgent need for more information and education for both relatives and the public in most European countries to improve awareness and understanding of BDs and other mood disorders and the doctor-patient dialogue.

Bipolar disorder in children and adolescents: diagnosis and treatment

An improved understanding of bipolar disorder should help clinicians in the accurate diagnosis and treatment of children and adolescents with bipolar disorder. Clinicians should use preliminary evidence and sound clinical judgment when working with patients who have, or may be at risk of, bipolar disorder. Purpose of review This article reviews current literature on the diagnosis and treatment of bipolar disorder in children and adolescents. Controversies relating to diagnosis, common comorbid psychiatric disorders, and the safety and efficacy of pharmocotherapy are summarized. Recent findings The presentation of bipolar disorder in children and adolescents has been described by some as ‘atypical’ in that (1) the predominant mood is often one of irritability, (2) the irritability may be severe, persistent, and violent, (3) the pattern of cycling may be ultradian, (4) comorbid psychiatric disorders and family history of bipolar disorder are common, and (5) poor treatment response and recurrence are common. However, given the prevalence of mixed mania in adult bipolar disorder and the similarities between childhood- and adolescent-onset bipolar disorder and mixed mania, some claim that the child and adolescent variant may not be atypical after all. Adding to the confusion are the diverse manifestations of bipolar symptoms at different developmental stages. Lithium, valproate, and carbamazepine are the medications most commonly used to treat children and adolescents with bipolar disorder. However, current practice parameters are based on preliminary evidence and/or studies using adult patients. There is a need for randomized, double-blind, controlled trials to determine medication safety and efficacy in children and adolescents with bipolar disorder.

CIRCADIAN RHYTHMS, MULTILEVEL MODELS OF EMOTION AND BIPOLAR DISORDER—AN INITIAL STEP TOWARDS INTEGRATION?

This paper sets out possible links between disruption of circadian rhythms in bipolar disorder and the affective symptom, which are experienced in this disorder. Evidence is drawn from Healy and Williams' [Psychiatr. Dev. 1 (1989) 49.] review of circadian function in manic depression, along with later reports, which indicate a role for disrupted circadian rhythms in both depressed and manic phases of manic depression (bipolar disorder). This is integrated within a version of the multilevel model of emotion proposed by Power and Dalgleish [ Cognition and emotion: from order to disorder. Hove: Psychology Press (1997); Behav. Cognit. Psychother. 27 (1999) 129.]. The aim of this process is to propose a possible psychological mechanism by which the disruption of circadian rhythms might result in the observed clinical symptoms of bipolar disorder. The integration of these approaches leads to a number of specific testable hypotheses that are relevant to future research into the psychological treatment and understanding of bipolar disorder.