Increased rates of white matter hyperintensities in late-onset bipolar disorder

Biomarkers of Bipolar Disorder in Late Life: An Evidence-Based Systematic Review

PURPOSE OF REVIEW

Review the current evidence on biomarkers for bipolar disorder in the older adults. We conducted a systematic search of PubMed MEDLINE, PsycINFO, and Web of Science databases using the MeSH search terms "Biomarkers", "Bipolar Disorder", "Aged" and and "Aged, 80 and over". Studies were included if they met the following criteria: (1) the mean age of the study population was 50 years old or older, (2) the study included patients with bipolar disorder, and (3) the study examined one type of biomarkers or more including genetic, neuroimaging, and biochemical biomarkers. Reviews, case reports, studies not in English and studies for which no full text was available were excluded. A total of 26 papers were included in the final analysis.

RECENT FINDINGS

Genomic markers of bipolar disorder in older adults highlighted the implication of serotonin metabolism, while the expression of genes involved in angiogenesis was dysregulated. Peripheral blood markers were mainly related with low grade inflammation, axonal damage, endothelial dysfunction, and the dysregulation of the HPA axis. Neuroanatomical markers reflected a dysfunction of the frontal cortex, a loss of neurones in the anterior cingulate cortex and a reduction of the hippocampal volume (in patients older than 50 years old). While not necessarily limited to older adults, some of them may be useful for differential diagnosis (neurofilaments), disease staging (homocysteine, BDNF) and the monitoring of treatment outcomes (matrix metalloproteinases). Our review provides a comprehensive overview of the current evidence on biomarkers for bipolar disorder in the older adults. The identification of biomarkers may aid in the diagnosis, treatment selection, and monitoring of bipolar disorder in older adults, ultimately leading to improved outcomes for this population. Further research is needed to validate and further explore the potential clinical utility of biomarkers in this population.

Late-Onset Bipolar Disorder: Considerations for Diagnosis and Treatment

Bipolar I disorder is characterized by the presence of at least one manic episode (DSM-5). Despite a decent percentage of individuals being diagnosed later in life, there currently exist no formal treatment guidelines for late-onset bipolar disorder (LOBD), which remains poorly understood. Typically, manic or manic-like episodes in elderly individuals can be thought of as arising from a secondary, physical cause. However, in the absence of a pre-existing neurological disorder - and when laboratory, imaging, and exam findings do not fully support a neurological picture - the determination of a structural versus primary etiology for LOBD becomes challenging. We present the case of Ms. S, a 79-year-old woman with a past psychiatry history of bipolar disorder diagnosed after 2012 and non-contributory past medical history who was admitted to a state mental hospital on a probate court order from local jail secondary to labile mood and physical aggression toward an officer. Initial labs were remarkable for slightly elevated low-density lipoprotein and a B12 at the lower limit of normal. She was started on a regiment oral B12 supplement, valproic acid 500 mg twice daily, haloperidol 5 mg nightly, and diphenhydramine 25 mg nightly. Despite her medication regimen, she continued to display marked mood lability, tangential thought processes, grandiose delusions, and paranoia. A CT head one week into admission revealed bilateral periventricular white-matter hyperintensities with decreased attenuation and chronic white-matter infarcts. She underwent five sessions of electroconvulsive therapy (ECT), with significantly improving Montreal Cognitive Assessment and Young Mania Rating Scale scores. At the time of discharge on day 32, the patient was fully oriented to self and surroundings with good hygiene, a normal rate of speech, euthymic mood, and congruent affect. The case of Ms. S underscores the importance of a thorough workup to rule out secondary causes of mania. In addition, it is a clarion call for revisiting and researching a comprehensive management approach to LOBD, for which serial cognitive assessments and ECTs may play an important role.

Neuroimaging Studies of Brain Structure in Older Adults with Bipolar Disorder: A Review

Bipolar disorder (BD) is a common mood disorder that can have severe consequences during later life, including suffering and impairment due to mood and cognitive symptoms, elevated risk for dementia and an especially high risk for suicide. Greater understanding of the brain circuitry differences involved in older adults with BD (OABD) in later life and their relationship to aging processes is required to improve outcomes of OABD. The current literature on gray and white matter findings, from high resolution structural and diffusion-weighted magnetic resonance imaging (MRI) studies, has shown that BD in younger age groups is associated with gray matter reductions within cortical and subcortical brain regions that subserve emotion processing and regulation, as well as reduced structural integrity of white matter tracts connecting these brain regions. While fewer neuroimaging studies have focused on OABD, it does appear that many of the structural brain differences found in younger samples are present in OABD. There is also initial suggestion that there are additional brain differences, for at least a subset of OABD, that may result from more pronounced gray and white matter declines with age that may contribute to adverse outcomes. Preclinical and clinical data supporting neuro-plastic and -protective effects of mood-stabilizing medications, suggest that treatments may reverse and/or prevent the progression of brain changes thereby reducing symptoms. Future neuroimaging research implementing longitudinal designs, and large-scale, multi-site initiatives with detailed clinical and treatment data, holds promise for reducing suffering, cognitive dysfunction and suicide in OABD.

White Matter Abnormalities in Late Onset First Episode Mania: A Diffusion Tensor Imaging Study

INTRODUCTION

A first manic episode after 50 years of age is uncommon. Late Onset Mania might be indicative of abnormalities in white matter, probably related to vascular, degenerative, or inflammatory processes.

OBJECTIVE

To determine if patients with late onset mania have reduced white matter integrity according to Magnetic Resonance Diffusion Tensor Imaging (DTI) and structural MRI.

METHODS

Twenty-two patients with late onset mania (>50 years old) and 22 age-paired healthy subjects were included in the study. Fractional anisotropy (FA) was used as a quantitative measure of white matter integrity. Fazekas scale was assessed also to measure white matter abnormalities in the FLAIR sequence. The Frontal Assessment Battery, COGNISTAT and Trail making test A and B were used as cognitive measurements.

RESULTS

According to DTI, commissural connections (left corpus callosum), and limbic connections (right and left uncinate fasciculus) were different between the patients and the comparison group. Fractional anisotropy values in the left corpus callosum showed significant correlations with neuropsychological measures, and with the Fazekas scale score. According to Fazekas scale, a pathological score in the FLAIR sequence was significantly more frequent in the patients as compared to the comparison group.

CONCLUSIONS

Patients with first episode mania in late life have relevant white matter abnormalities not explained by age, affecting interhemispheric and fronto-limbic networks probably related to executive functioning and emotional processing, at the level of the corpus callosum and the uncinate fasciculus. The etiology of this white matter loss of integrity in patients with late-onset mania is yet to be explored.

Evaluation and treatment of older-age bipolar disorder: a narrative review

Objectives

This narrative review aims to synthesize information from the literature regarding older-age bipolar disorder (OABD) in order to provide up-to-date information on this important illness.

Methods

We searched Ovid (Medline, Embase and PsychInfo) on October 1, 2020, using the keywords “bipolar disorder”, “older adults” and “elderly” to identify relevant articles on OABD. Additionally, the bibliography of identified articles was reviewed for pertinent studies.

Discussions

OABD is a term that is used to describe bipolar disorder (BD) occurring amongst individuals ≥50 years of age. Evidence indicates that OABD accounts for a quarter of all cases of BD. When compared to individuals with early-onset BD, individuals with OABD have a greater association with cerebrovascular disease and other neurological disorders, less family history of mood disorders, and utilize almost four times the total amount of mental health services. In addition, they are four times more likely to have psychiatric hospitalizations when compared to age-matched controls. Despite a dearth of controlled studies on the use of pharmacotherapy amongst individuals with OABD, available evidence from mixed-age studies indicates the efficacy of commonly used medications in individuals with early-onset BD. Additionally, psychosocial treatments have been found to be effective as adjunctive management strategies amongst individuals with OABD. Furthermore, electroconvulsive therapy may be effective in the treatment of refractory cases of OABD.

Conclusions

There is a great need for an improved understanding of the phenomenology and neurobiology of OABD. Additionally, research into effective treatments for this serious psychiatric disorder will mitigate the suffering of individuals with OABD.

Episode of mixed mood with psychotic features secondary to Binswanger disease: a case report with a literature review

Neurodegenerative and mood disorders in the geriatric population might exhibit interchangeable cognitive and behavioural symptoms. This overlap in presentation might raise a diagnostic challenge for psychiatrists evaluating elderly patients who are presenting with such symptoms. Additionally, there is limited data published about early psychiatric manifestations of neurodegenerative disorders in the elderly. We report a case of a 71-year-old with a history of refractory depressive disorder and multiple cardiovascular risk factors presenting with verbalisation of suicidal and homicidal intent as well as mixed mood and psychotic symptoms. The patient was diagnosed with Binswanger's disease (BD). We also provide a literature review of challenging early psychiatric presentations of neurocognitive disorders and a summary of similar cases to help facilitate diagnosis of BD cases in future.

Confining the Concept of Vascular Depression to Late-Onset Depression: A Meta-Analysis of MRI-Defined Hyperintensity Burden in Major Depressive Disorder and Bipolar Disorder

Background: The vascular depression hypothesis emphasizes the significance of vascular lesions in late-life depression. At present, no meta-analytic model has investigated whether a difference in hyperintensity burden compared to controls between late-life and late-onset depression is evident. By including a substantial number of studies, focusing on a meaningful outcome measure, and considering several moderating and control variables, the present meta-analysis investigates the severity of hyperintensity burden in major depressive disorder (MDD) and bipolar disorder (BD). A major focus of the present meta-analysis refers to the role of age at illness onset. It is analyzed whether late-onset rather than late-life depression characterizes vascular depression. Method: In total, 68 studies were included in the meta-analysis and a multilevel random effects model was calculated using Hedges' g as the effect size measure. Results: The severity of hyperintensity burden was significantly greater in the patient group compared to the control group. This effect was evident regarding the whole patient group (g = 0.229) as well as both depression subgroups, with a significantly greater effect in BD (g = 0.374) compared to MDD (g = 0.189). Hyperintensity burden was more pronounced in late-onset depression than in early-onset depression or late-life depression. A considerable heterogeneity between the included studies was observed, which is reflected by the large variability in effects sizes. Conclusion: In conclusion, the present meta-analysis underscores the association of hyperintensities with MDD and BD. Especially late-onset depression is associated with an increased hyperintensity burden, which is in line with the vascular depression hypothesis. The results suggest that it might be more feasible to confine the concept of vascular depression specifically to late-onset depression as opposed to late-life depression. Further research is needed to understand the causal mechanisms that might underlie the relation between hyperintensity burden and depression.

White matter hyperintensities in young individuals with bipolar disorder or at high genetic risk

BACKGROUND

Increased white matter hyperintensities (WMHs) is one of the most consistent imaging findings amongst participants with bipolar disorder (BD). This study investigated WMHs in a young population at high genetic risk for bipolar disorder (HR).

METHODS

MRI scans were conducted at baseline in HR individuals (n = 131), patients with BD (n = 47) and controls (CON) (n = 108). Most of the HR (n = 77) and CON (n = 74) group completed scans after two years. Scans were examined for the presence of WMHs.

RESULTS

There were significantly more periventricular WMHs in the BD compared to the CON group at baseline (p = .04). Although the prevalence of periventricular WMHs was intermediate in the HR group, there were no significant differences between the HR and CON or BD participants. Deep WMHs did not differ significantly between the groups. Over time, there was a significant increase in the prevalence of periventricular WMHs in both the HR and CON groups (p = .02).

LIMITATIONS

The use of a visual rating scale to examine WMHs is subjective. As the gradings were collapsed into 'present' or 'absent', we could not ascertain whether the severity of hyperintensities worsened over time.

CONCLUSIONS

Periventricular WMHs are more prevalent in young individuals with BD than controls. As these are not more prevalent in HR individuals, it is possible that these are either secondary to the development of bipolar disorder, its treatment, or resulting changes in lifestyle. In a novel finding, there were similar increases in the prevalence of WMHs in controls and HR youth over the 2-year period.

Understanding and managing cognitive impairment in bipolar disorder in older people

Bipolar disorder is less prevalent in older people but accounts for 8–10% of psychiatric admissions. Treating and managing bipolar disorder in older people is challenging because of medical comorbidity. We review the cognitive problems observed in older people, explore why these are important and consider current treatment options. There are very few studies examining the cognitive profiles of older people with bipolar disorder and symptomatic depression and mania, and these show significant impairments in executive function. Most studies have focused on cognitive impairment in euthymic older people: as in euthymic adults of working age, significant impairments are observed in tests of attention, memory and executive function/processing speeds. Screening tests are not always helpful in euthymic older people as the impairment can be relatively subtle, and more in-depth neuropsychological testing may be needed to show impairments. Cognitive impairment may be more pronounced in older people with ‘late-onset’ bipolar disorder than in those with ‘early-onset’ disorder. Strategies to address symptomatic cognitive impairment in older people include assertive treatment of the mood disorder, minimising drugs that can adversely affect cognition, optimising physical healthcare and reducing relapse rates.

LEARNING OBJECTIVES

After reading this article you will be able to: •

DECLARATION OF INTEREST

B.J.S. consults for Cambridge Cognition, PEAK (www.peak.net) and Mundipharma.

Development of Neuroimaging-Based Biomarkers in Psychiatry

This chapter presents an overview of accumulating neuroimaging data with emphasis on translational potential. The subject will be described in the context of three disease states, i.e., schizophrenia, bipolar disorder, and major depressive disorder, and for three clinical goals, i.e., disease risk assessment, subtyping, and treatment decision.

Advances and Barriers for Clinical Neuroimaging in Late-Life Mood and Anxiety Disorders

PURPOSE OF REVIEW

Mood and anxiety disorders are very commonly experienced by older adults and are becoming a growing concern due to the rapidly aging global population. Recent advances in neuroimaging may help in improving outcomes in late-life mood and anxiety disorders. The elucidation of mechanisms contributing to late-life mental health disorders may ultimately lead to the identification of novel therapeutic interventions. Alternatively, clinically validated imaging biomarkers may allow for the prediction of treatment response and identification of better therapeutic approaches in late-life mood and anxiety disorders.

RECENT FINDINGS

In community samples, late-life depression and late-life generalized anxiety disorder occur up to 38 and 15%, respectively, while late-life bipolar disorder is less common and occur in approximately 0.5% of the population. There are significant challenges in treating and improving outcome in late-life mood and anxiety disorders. Time to treatment response and treatment resistance are increased in older adults. Novel neuroimaging techniques have the potential to improve diagnostic and therapeutic outcome in late-life mood and anxiety disorders either through "personalized pharmacotherapy" or through identifying dysfunction regions/networks to be subsequently used for direct interventions such as transcranial magnetic stimulation. This review will provide an overview of recent literature that substantiates the potential role of neuroimaging in clinical practice, as well as the barriers that must be overcome prior to clinical translation.

Psychotropic use and risk of stroke among patients with bipolar disorders: 10-year nationwide population based study

OBJECTIVES

To investigate the association between psychotropic agents (including antipsychotics, antidepressants and mood stabilizers) and risk of stroke among patients with bipolar disorders.

METHODS

We conducted a disease risk score-matched nested case-control study and identified patients with bipolar disorders (ICD-9 codes: 296.0x, 296.1x, 296.4x, 296.5x, 296.6x, 296.7x, 296.80, 296.81 or 296.89) from the National Health Insurance Research Database in Taiwan. Among them, we identified 1232 cases (981 were ischemic stroke and 251 were hemorrhagic stroke) and 5314 disease risk score-matched controls. Conditional logistic regression model equations were applied to determine the effect of psychotropic agents on stroke risk among patients with bipolar disorders.

RESULTS

The results indicated that overall use of psychotropic agents was associated with an increased risk of stroke (adjusted odds ratio [AOR] = 1.82; 95% confidence interval [CI]: 1.56-2.13). When classifying psychotropic agents into antipsychotics, antidepressants and mood stabilizers, respectively, a significant positive association was found for users of antipsychotics (AOR = 1.98; 95% CI = 1.53-2.56), antidepressants (AOR = 1.44; 95% CI = 1.16-1.79), and mood stabilizers (AOR = 1.89; 95% CI = 1.22-2.93). Combined use of psychotropic agents was associated with higher risk of stroke than monotherapy (AOR = 2.62; 95% CI = 1.98-3.45).

DISCUSSIONS

The results support our hypothesis that psychotropic use is associated with increased risk of stroke among patients with bipolar disorders. The stroke risks are higher among patients with polypharmacy than those with monotherapy. These findings warrant further investigation to confirm and replicate the findings using different methodologies and populations, and to mitigate residual confounding.

White Matter Microstructural Changes and Episodic Memory Disturbances in Late-Onset Bipolar Disorder

Background: Bipolar disorder (BD) has been associated with distributed network disruption, but little is known on how different clinical subtypes, particularly those with an earlier and later onset of disease, are related to connectivity changes in white matter (WM) tracts. Methods: Diffusion tensor imaging (DTI) and volumetric measures were carried out in early-onset bipolar patients [(EOD) (n = 16)], late-onset bipolar disorder [(LOD)(n = 14)] and healthy controls (n = 32). We also computed ROI analysis of gray matter (GM) and white matter (WM) volumes using the regions with significant group differences in the DTI parameters. Cognitive and behavior measurements were analyzed between groups. Results: Lower fraction of anisotropy (FA) in the right hemisphere comprising anterior thalamic radiation, fornix, posterior cingulate, internal capsule, splenium of corpus callosum was observed in the LOD in comparison with EOD; additionally, lower FA was also found in the LOD in comparison with healthy controls, mostly in the right hemisphere and comprising fibers of the splenium of the corpus callosum, cingulum, superior frontal gyrus and posterior thalamic radiation; LOD also showed worse episodic memory performance than EOD; no statistical significant differences between mood symptoms, WM and GM volumes were found between BD groups. Conclusion: Even after correcting for age differences, LOD was associated with more extensive WM microstructural changes and worse episodic memory performance than EOD; these findings suggest that changes in the WM fiber integrity may be associated with a later presentation of BD, possibly due to mechanisms other than neuroprogression. However, these findings deserve replication in larger, prospective, studies.

Recommencing lithium in Older Adults with Bipolar I Disorder

OBJECTIVES

This paper addresses considerations in recommencing lithium in elderly patients with Bipolar I Disorder and medical comorbidity. We focus on nephrotoxicity and cognitive impairment.

METHODS

Case reports and review of relevant literature.

RESULTS

Three elderly psychogeriatric inpatients admitted with severe manic relapse following lithium cessation are described. In all cases, lithium was recommenced safely with good response.

CONCLUSIONS

Even with medical comorbidity it may be possible to recommence modified lithium therapy.

Can neuroimaging disentangle bipolar disorder?

BACKGROUND

Bipolar disorder heterogeneity is large, leading to difficulties in identifying neuropathophysiological and etiological mechanisms and hindering the formation of clinically homogeneous patient groups in clinical trials. Identifying markers of clinically more homogeneous groups would help disentangle BD heterogeneity. Neuroimaging may aid in identifying such groups by highlighting specific biomarkers of BD subtypes or clinical dimensions.

METHODS

We performed a systematic literature search of the neuroimaging literature assessing biomarkers of relevant BD phenotypes (type-I vs. II, presence vs. absence of psychotic features, suicidal behavior and impulsivity, rapid cycling, good vs. poor medication response, age at onset, cognitive performance and circadian abnormalities).

RESULTS

Consistent biomarkers were associated with suicidal behavior, i.e. frontal/anterior alterations (prefrontal and cingulate grey matter, prefrontal white matter) in patients with a history of suicide attempts; and with cognitive performance, i.e. involvement of frontal and temporal regions, superior and inferior longitudinal fasciculus, right thalamic radiation, and corpus callosum in executive dysfunctions. For the other dimensions and sub-types studied, no consistent biomarkers were identified.

LIMITATIONS

Studies were heterogeneous both in methodology and outcome.

CONCLUSIONS

Though theoretically promising, neuroimaging has not yet proven capable of disentangling subtypes and dimensions of bipolar disorder, due to high between-study heterogeneity. We issue recommendations for future studies.

Late onset mania as an organic syndrome: A review of case reports in the literature

AIMS

Although First Episode Mania presenting over the age of 50 is reported in several cases, there has been little systematic compilation of these case reports. We report a review of case reports on these subjects.

METHODS

We undertook a literature search on MEDLINE, PsychInfo and EMBASE to identify case reports of first episode of mania or hypomania presenting over the age of 50.

RESULTS

35 cases were identified. 29/35 (82%) had a suspected underlying organic cause. Organic causes included vascular causes, iatrogenic drug use, electrolyte imbalance, dementia and thyroid disease. Vascular risk factors were present in 17/35 cases (48%). In 10/35 (28%) of cases organic treatment contributed to successful remission of the manic episode.

LIMITATIONS

As evidently not all cases have been reported the main limitation is that of publication bias for this paper. Any such hypothesis generated from studying these cases would require replication in prospective longitudinal trials of this cohort of patients.

CONCLUSIONS

This review of case reports appears to add to evidence of late onset mania having an organic basis. Whether this is a separate organic syndrome remains to be established. Our provisional findings suggest that such patients should have a thorough medical and psychiatric screening in identifying an underlying cause.

A report on older-age bipolar disorder from the International Society for Bipolar Disorders Task Force

OBJECTIVES

In the coming generation, older adults with bipolar disorder (BD) will increase in absolute numbers as well as proportion of the general population. This is the first report of the International Society for Bipolar Disorder (ISBD) Task Force on Older-Age Bipolar Disorder (OABD).

METHODS

This task force report addresses the unique aspects of OABD including epidemiology and clinical features, neuropathology and biomarkers, physical health, cognition, and care approaches.

RESULTS

The report describes an expert consensus summary on OABD that is intended to advance the care of patients, and shed light on issues of relevance to BD research across the lifespan. Although there is still a dearth of research and health efforts focused on older adults with BD, emerging data have brought some answers, innovative questions, and novel perspectives related to the notion of late onset, medical comorbidity, and the vexing issue of cognitive impairment and decline.

CONCLUSIONS

Improving our understanding of the biological, clinical, and social underpinnings relevant to OABD is an indispensable step in building a complete map of BD across the lifespan.

Psychosis in Later Life: A Review and Update

Psychosis is relatively common in later life and can present in a wide variety of contexts, including early-onset and late-onset schizophrenia, delusional disorder, mood disorders, and various dementias. It can also occur as the result of numerous medical and neurological diseases and from the use of certain medications. Although identifying the cause of psychosis in older patients can be challenging, the unique clinical features associated with the different disorders can help in making the diagnosis. Accurate diagnosis of psychosis in older populations is essential, as its treatment varies depending on the context in which it appears. Despite the safety concerns regarding the use of antipsychotics in older patients, certain pharmacological treatments appear to be both efficacious and reasonably safe in treating psychosis in older populations. Additionally, although research is limited, numerous psychosocial therapies appear promising. This review summarizes the literature on the epidemiology, clinical characteristics, neuroimaging, and treatment of psychosis in later life, and serves as an update to past reviews on this topic.

Longer lithium exposure is associated with better white matter integrity in older adults with bipolar disorder

OBJECTIVES

Bipolar disorder (BD) is associated with cognitive dysfunction and structural brain abnormalities. In human and non-human studies, lithium has been related to neuroprotective and neurotrophic effects. We explored whether lithium treatment is related to better brain integrity and cognitive function in older adults with BD.

METHODS

We examined cognitive and neuroimaging data in 58 individuals with BD [mean (standard deviation) age = 64.5 (9.8) years] and 21 mentally healthy comparators (controls) of similar age and education. Subjects received comprehensive neurocognitive assessment and structural brain imaging, examining total gray matter volume, overall white matter integrity (fractional anisotropy), and total white matter hyperintensity burden.

RESULTS

In comparison to controls, subjects with BD had worse overall cognitive performance, lower total gray matter volume, and lower white matter integrity. Among subjects with BD, longer duration of lithium treatment was related to higher white matter integrity after controlling for age and vascular disease burden, but not with better cognitive performance.

CONCLUSIONS

Lithium treatment appears to be related to better brain integrity in older individuals with BD, in particular, in those who take lithium long-term. While intriguing, these findings need to be confirmed in a larger sample.

Two years' outcome of acute mania in bipolar disorder: different effects of age and age of onset

BACKGROUND

Information about differences between younger and older patients with bipolar disorder and between older patients with early and late age of onset of illness during long-term treatment is scarce.

OBJECTIVES

This study aimed to investigate the differences in treatment and treatment outcome between older and younger manic bipolar patients and between early-onset bipolar (EOB) and late-onset bipolar (LOB) older patients.

METHOD

The European Mania in Bipolar Longitudinal Evaluation of Medication study was a 2-year prospective, observational study in 3459 bipolar patients on the treatment and outcome of patients with an acute manic or mixed episode. Patients were assessed at 6, 12, 18, and 24 months post-baseline. We calculated the number of patients with a remission, recovery, relapse, and recurrence and the mean time to achieve this.

RESULTS

Older patients did not differ from younger bipolar patients in achieving remission and recovery or suffering a relapse and in the time to achieve this. However, more older patients recurred and in shorter time. Older patients used less atypical antipsychotics and more antidepressants and other concomitant psychiatric medication. Older EOB and LOB patients did not differ in treatment, but more older LOB patients tended to recover than older EOB patients.

CONCLUSION

Older bipolar manic patients did not differ from younger bipolar patients in short-term treatment outcome (remission and recovery), but in the long term, this may be more difficult to maintain. Distinguishing age groups in bipolar study populations may be useful when considering treatment and treatment outcome and warrants further study.

Neuroprogressive effects of lifetime illness duration in older adults with bipolar disorder

OBJECTIVE

The aim of the present study was to examine the long-term effects of bipolar disorder (BD) on brain structure (gray matter volumes).

METHODS

Fifty-four adults with BD [mean (standard deviation) age = 64.4 (5.4) years] underwent brain MR imaging along with comprehensive clinical assessment. Total gray matter, hippocampal, and amygdala volumes were extracted using methods developed through the Geriatric Neuroimaging Laboratory at the University of Pittsburgh (Pittsburgh, PA, USA).

RESULTS

Lower total gray matter volumes were related to longer duration of BD, even when controlling for current age and cerebrovascular accident (CVA) risk/burden. Additionally, longer exposure to antipsychotic medication was related to lower gray matter volumes. Lower hippocampal volumes were related to total years of antipsychotic agent exposure and CVA risk/burden scores. Older age was related to lower total gray matter, hippocampal, and amgydala volumes.

CONCLUSIONS

Our study of older adults with BD supports the understanding that BD is a neuroprogressive disorder with a longer duration of illness and more antipsychotic agent exposure related to lower gray matter volume.

Neuroimaging and neurocognitive abnormalities associated with bipolar disorder in old age

OBJECTIVES

Cognitive dysfunction is prevalent in older adults with bipolar disorder (BD). High white matter hyperintensity (WMH) burden, a marker of white matter disease, detected on T2/fluid-attenuated inversion recovery brain magnetic resonance imaging (MRI) has been consistently reported in BD across all age ranges, including older adults. Yet, whether high WMH burden is related to the excess cognitive impairment present in older adults with BD is unknown. Therefore, we examine whether higher WMH burden is related to worse cognitive function in older adults with BD.

METHODS

This is a cross-sectional study of 27 non-demented BD patients aged ≥50 years and 12 similarly aged mentally healthy comparators (controls). Subjects underwent both brain MRI and comprehensive neurocognitive assessment. We employed correlational analyses to evaluate the burden of WMH and the relationship between WMH and cognitive function.

RESULTS

Although BD subjects had worse performance in all cognitive domains, BD subjects had less total WMH burden (t[13.4] = -3.57, p = 0.003). In control subjects, higher WMH was related to lower global cognitive function (ρ = -0.57, n = 12, p = 0.05). However, WMH did not correlate with neuropsychological performance in BD subjects. Further, BD and control subjects did not differ with respect to total gray and hippocampal volumes.

CONCLUSIONS

Cognitive dysfunction in late-life BD does not appear to be due primarily to processes related to increased WMH or reduced gray matter volume. Future longitudinal studies should examine other potential neuroprogressive pathways such as inflammation, mitochondrial dysfunction, serum anticholinergic burden, and altered neurogenesis.

Frontotemporal White Matter in Adolescents with, and at-Risk for, Bipolar Disorder

Frontotemporal neural systems are highly implicated in the emotional dysregulation characteristic of bipolar disorder (BD). Convergent genetic, postmortem, behavioral and neuroimaging evidence suggests abnormalities in the development of frontotemporal white matter (WM) in the pathophysiology of BD. This review discusses evidence for the involvement of abnormal WM development in BD during adolescence, with a focus on frontotemporal WM. Findings from diffusion tensor imaging (DTI) studies in adults and adolescents are reviewed to explore possible progressive WM abnormalities in the disorder. Intra- and interhemispheric frontotemporal abnormalities were reported in adults with BD. Although evidence in children and adolescents with BD to date has been limited, similar intrahemispheric and interhemispheric findings have also been reported. The findings in youths suggest that these abnormalities may represent a trait marker present early in the course of BD. Functional connectivity studies, demonstrating a relationship between WM abnormalities and frontotemporal dysfunction in BD, and DTI studies of vulnerability in first-degree relatives of individuals with BD, are discussed. Together, findings suggest the involvement of abnormal frontotemporal WM development in the pathophysiology of BD and that these abnormalities may be early trait markers of vulnerability; however, more studies are critically needed.

Neuroimaging findings in late-onset schizophrenia and bipolar disorder

In recent years, there has been an increasing interest in late-onset mental disorders. Among them, geriatric schizophrenia and bipolar disorder are significant health care risks and major causes of disability. We discussed whether late-onset schizophrenia (LOS) and late-onset bipolar (LOB) disorder can be a separate entity from early-onset schizophrenia (EOS) and early-onset bipolar (EOB) disorder in a subset of late-life schizophrenia or late-life bipolar disorder through neuroimaging studies. A literature search for imaging studies of LOS or LOB was performed in the PubMed database. Search terms used were "(imaging OR MRI OR CT OR SPECT OR DTI OR PET OR fMRI) AND (schizophrenia or bipolar disorder) AND late onset." Articles that were published in English before October 2013 were included. There were a few neuroimaging studies assessing whether LOS and LOB had different disease-specific neural substrates compared with EOS and EOB. These researches mainly observed volumetric differences in specific brain regions, white matter hyperintensities, diffusion tensor imaging, or functional neuroimaging to explore the differences between LOS and LOB and EOS and EOB. The aim of this review was to highlight the neural substrates involved in LOS and LOB through neuroimaging studies. The exploration of neuroanatomical markers may be the key to the understanding of underlying neurobiology in LOS and LOB.

White matter abnormalities associated with Alzheimer's disease and mild cognitive impairment: a critical review of MRI studies

In this article, the authors aim to present a critical review of recent MRI studies addressing white matter (WM) abnormalities in Alzheimer's disease (AD) and mild cognitive impairment (MCI), by searching PubMed and reviewing MRI studies evaluating subjects with AD or MCI using WM volumetric methods, diffusion tensor imaging and assessment of WM hyperintensities. Studies have found that, compared with healthy controls, AD and MCI samples display WM volumetric reductions and diffusion tensor imaging findings suggestive of reduced WM integrity. These changes affect complex networks relevant to episodic memory and other cognitive processes, including fiber connections that directly link medial temporal structures and the corpus callosum. Abnormalities in cortico-cortical and cortico-subcortical WM interconnections are associated with an increased risk of progression from MCI to dementia. It can be concluded that WM abnormalities are detectable in early stages of AD and MCI. Degeneration of WM networks causes disconnection among neural cells and the degree of such changes is related to cognitive decline.

A quantitative review of neurocognition in euthymic late-life bipolar disorder

OBJECTIVES

A sizeable body of work has consistently documented that a number of euthymic mixed-age bipolar disorder subjects exhibit prominent impairments in a variety of cognitive domains. By contrast, knowledge about neuropsychological functioning in elderly patients is scant, despite being necessary for the adequate treatment of this population and the understanding of illness evolution. The aim of this study was to combine findings from the available literature in order to examine the pattern and extent of cognitive deficits in euthymic late-life bipolar disorder subjects.

METHODS

A literature search was conducted through the online databases PubMed, ScienceDirect, EBSCO, and Wiley-Blackwell, covering the period between January 1990 and April 2012. Effect sizes reflecting patient-control differences for 10 cognitive variables were extracted from selected investigations and combined by means of meta-analytical procedures.

RESULTS

No significant patient-control differences were found for global cognitive status as assessed with the Mini-Mental State Examination and the Clock Drawing Test. Significant overall effect sizes (Hedges' g) of between 0.61 and 0.88 were noted for sustained attention, digit span (forwards and backwards), delayed recall, serial learning, cognitive flexibility, and verbal fluency (phonemic and categorical).

CONCLUSIONS

The extent of cognitive dysfunction in euthymic late-life bipolar disorder subjects may be, on average, similar to that reported for remitted young adult patients. Larger effect sizes of impairment may be associated with late illness onset. Implications and future directions for research are proposed.

The overlap of symptomatic dimensions between frontotemporal dementia and several psychiatric disorders that appear in late adulthood

Several factors make diagnosis of a possible behavioural variant of frontotemporal dementia (bvFTD) particularly challenging, especially the overlap of certain symptomatic dimensions such as apathy, disinhibition, depression, anhedonia, stereotyped behaviour, and psychosis between bvFTD and several psychiatric disorders that appear in late adulthood. We discuss the most frequent psychiatric conditions that can simulate early bvFTD symptoms, including late onset bipolar disorder, late onset schizophrenia-like psychosis, late onset depression, and attention deficit hyperactivity disorder in middle and older age.

Organic bases of late-life depression: a critical update

Late-life depression (LLD) is frequently associated with cognitive impairment and increases the risk of subsequent dementia. Cerebrovascular disease, deep white matter lesions, Alzheimer disease (AD) and dementia with Lewy bodies (DLB) have all been hypothesized to contribute to this increased risk, and a host of studies have looked at the interplay between cerebrovascular disease and LLD. This has resulted in new concepts of LLD, such as "vascular depression", but despite multiple magnetic resonance imaging (MRI) studies in this field, the relationship between structural changes in human brain and LLD is still controversial. While pathological findings of suicide in some elderly persons revealed multiple lacunes, small vessel cerebrovascular disease, AD-related lesions or multiple neurodegenerative pathologies, recent autopsy data challenged the role of subcortical lacunes and white matter lesions as major morphological substrates of depressive symptoms as well as poorer executive function and memory. Several neuropathological studies, including a personal clinico-pathological study in a small cohort of elderly persons with LLD and age-matched controls confirmed that lacunes, periventricular and deep white matter demyelination as well as AD-related lesions are usually unrelated to the occurrence of LLD. In the same line, neuropathological data show that early-onset depression is not associated with an acceleration of age-related neurodegenerative changes. Very recent data on the critical role of glia-modulating neuronal dysfunction and degeneration in depression are discussed.

Total white matter hyperintensity volume in bipolar disorder patients and their healthy relatives

OBJECTIVES

White matter hyperintensities (WMH) are more common in subjects with bipolar disorder (BP) than in healthy subjects (HS). Few studies have examined the effect of the diagnostic type of bipolar illness on WMH burden, and none have approached this question through a direct measurement of the volume of affected white matter in relationship to familiality. In this pilot study, we utilized a volumetric measurement of WMH to investigate the relationship between the total volume of WMH and the familiality and type of BP.

METHODS

Forty-five individuals with bipolar I disorder (BP-I) with psychotic features, BP-I without psychotic features, or bipolar II disorder (BP-II), seven of their unaffected relatives, and 32 HS were recruited for participation. T-2 weighted magnetic resonance imaging scans were obtained on all subjects, and the total volume of all WMH for each subject was measured in cubic centimeters. The significance of difference between groups was tested using ANOVA with post-hoc adjustment for multiple comparisons. Further, we used logistic regression to test for trends between symptom load and total WMH volume.

RESULTS

The mean total volume of WMH in BP-I patients with psychotic features was significantly higher (p < 0.05) than that of HS. Further, we observed a positive linear trend by familiality and type of affectedness when comparing mean total WMH volume of HS, unaffected family members, subjects with BP-II, and BP-I with and without a history of psychosis (p < 0.05).

CONCLUSIONS

Based on a quantitative technique, WMH burden appears to be associated with familiality and type of BP. The significance of these findings remains to be fully elucidated.

White matter hyperintensities: from medical comorbidities to bipolar disorders and back

White matter hyperintensities (WMHs) are among the most replicated neuroimaging findings in studies of patients with bipolar disorders (BD). Despite the high rates of WMHs, their role and etiology in BD are not well understood. WMHs occur in multiple other conditions frequently co-morbid with BD. From the available studies it seems that WMHs are not a primary risk factor/endophenotype for BD. More likely, these lesions indicate the presence of medical co-morbidities with specific links to BD. Furthermore, the etiology of the WMHs in BD may represent different processes depending on age. In certain forms of BD, such as pediatric BD, WMHs may represent co-morbidity with developmental disorders. High frequency of migraine in BD and high prevalence of WMHs in migraine may suggest that a substantial proportion of WMHs in early adulthood to midlife BD subjects may be related to co-morbidity with migraine. Among elderly subjects with BD, or those with late-onset BD, WMHs are likely related to the presence of cardiovascular/metabolic disorders. With further research WMHs may enhance our knowledge about various pathological pathways involved in BD, help in decreasing the etiological heterogeneity of BD, and become useful as markers of severity or subtype of BD.

White matter hyperintensities in affected and unaffected late teenage and early adulthood offspring of bipolar parents: a two-center high-risk study

BACKGROUND

White matter hyperintensities (WMHs) are among the most replicated neuroimaging findings in bipolar disorder (BD). It is not clear whether these lesions are an artifact of comorbid conditions, or whether they are directly associated with the disorder, or even represent biological risk factor for BD.

METHODS

To test whether WMHs meet criteria for an endophenotype of BD, we conducted a high-risk design study and recruited 35 affected, 44 unaffected relatives of bipolar probands (age range 15-30 years), matched by age and sex with 49 healthy controls without any personal or family history of psychiatric disorders. The presence of WMHs was determined from Fluid Attenuated Inversion Recovery (FLAIR) scans acquired on a 1.5 Tesla scanner using a validated semi-quantitative scale.

RESULTS

We found mostly low grade WMHs in all groups. The proportion of WMH-positive subjects was comparable between the unaffected high-risk, affected familial and control groups.

CONCLUSION

White matter hyperintensities did not meet criteria for an endophenotype of BD. Bipolar disorder in young subjects without comorbid conditions was not associated with increased rate of WMHs.

Course and outcome of bipolar disorder

Bipolar disorder (BPD) is capricious illness. For some, it is a condition of few episodes; for others, it is unremitting. For some, elevated moods predominate; for others, depression is the major key. For a minority, the condition is predictably cyclical; for most, it is unpredictably chaotic. This chapter examines those studies that have attempted to draw coherence from this enigmatic disorder. Where possible, we will focus on data derived from prospective longitudinal investigations, while using as necessary the more limited retrospective or cross-sectional reports. For the sake of parsimony, we will limit discussion to those studies that have used the conservative historical definitions of BPD (as used in DSM-IIIR, DSM-IV, and ICD-10), eschewing the recent controversial concepts of "pediatric" BPD and "soft BPD spectrum."

Vascular diseases and old age mental disorders: an update of neuroimaging findings

PURPOSE OF REVIEW

To review neuroimaging findings that have been reported in samples of patients with cardiovascular disorders and their association with the onset of Alzheimer's disease, vascular dementia, depression and bipolar disorder in the elderly and to highlight the implications of these findings to the knowledge about the pathophysiology of psychiatric disorders in old age, as well as their potential clinical implications.

RECENT FINDINGS

Vascular risk factors, such as hypertension, diabetes, dyslipidemia, smoking habits and heart failure, have all been associated with signs of cerebrovascular dysfunction, including structural MRI findings of signal hyperintensities, lacunes and stroke and functional imaging findings of brain regional hypoperfusion and hypometabolism. Such brain abnormalities have been found to increase the risk of onset of psychiatric disorder (depression, bipolar and dementia) in old age.

SUMMARY

As vascular risk factors are potentially modifiable when detected in midlife, the early characterization of brain changes associated with the presence of cardiovascular diseases holds promise to afford clinical applications in psychiatry, providing new perspectives for the prevention of old age psychiatric disorders.

Risk factors for cognitive impairment in elderly bipolar patients

OBJECTIVE

Cognitive impairment in elderly bipolar patients persists during euthymic state, yet the aetiology of such impairment is not well understood. The objective of this study is to identify factors contributing to cognitive impairment in elderly patients with bipolar disorder.

METHOD

119 older patients (age >60) with bipolar I or II disorder in a euthymic state were extensively tested on cognitive functioning including attention, memory, visuoconstruction, executive function and verbal fluency with regard to potential risk factors.

RESULTS

Regression analysis shows that health related factors, medication and illness characteristics are associated with cognitive impairment in several cognitive domains: attention, memory, visuoconstruction, executive function and verbal fluency. More vascular burden factors are related to poorer outcome of cognitive functioning. Patients with lithium pharmacotherapy performed worse compared to those with other mood stabilizers, but this was no longer significant in multivariate analysis.

CONCLUSIONS

In elderly bipolar patients, more vascular risk factors and more hospital admissions are associated with more cognitive impairment.

'Bipolar disorder' in the elderly: what's in a name?

Bipolar disorder is a chronic disorder of mood which leads to episodes of either elevated mood or depression in a sizable number of adults in the community (1%). Though the prevalence rates in the elderly are lower in the community (up to 0.1%), there is significantly higher morbidity in protected environments like care homes and hospital settings where prevalence rates may be as high as 10%. Bipolar disorder in the elderly is probably heterogenous and its etiopathogenesis is complex. Bipolar disorder may be divided into two distinct subtypes, the late onset bipolar (LOB) and the early onset bipolar (EOB) groups. LOB patients tend to have a milder illness in terms of manic severity but they have higher medical and neurological burden. They also have lower familial burden of bipolar illness as compared to EOB patients. There is an increased risk of dementia and stroke in patients with late life bipolar disorder (and there may be a protective effect of lithium in preventing dementia). White matter changes, as seen by increased white matter hyperintensities on neuroimaging, are also increased, providing further evidence of cerebrovascular disease. Treatment of late life bipolar is currently based on guidelines drawn up for younger bipolar disorder patients. Good quality intervention studies are needed to estimate the possible protective effect of cognitive enhancers and/or vascular prevention strategies. This review suggests that late life bipolar disorder, particularly late onset bipolar disorder, is probably a distinct diagnostic entity compared to the younger bipolar patients as it has a different presentation, etiology and hence perhaps needs different treatment strategies.

A role for white matter abnormalities in the pathophysiology of bipolar disorder

Bipolar disorder is a chronically disabling psychiatric disorder characterized by manic states that is often interspersed with periods of depression whose neurobiology remains largely unknown. There is, however, increasing evidence that white matter (WM) abnormalities may play an important role in the neurobiology of the disorder. In this review we critically evaluate evidence for WM abnormalities in bipolar disorder obtained from neuroimaging, neuropathological, and genetic research. Increased rates of white matter hyperintensities, regional volumetric abnormalities, abnormal water diffusion along prefrontal-subcortical tracts, fewer oligodendrocytes in prefrontal WM, and alterations in the expression of myelin- and oligodendrocyte-related genes are among the most consistent findings. Abnormalities converge in the prefrontal WM and, in particular, tracts that connect prefrontal regions and subcortical gray matter structures known to be involved in emotion. Taken together, the evidence supports and clarifies a model of BD that involves disconnectivity in regions implicated in emotion generation and regulation.