Bipolar disorder and frontotemporal dementia: A systematic review

TDP-43 deficiency in suprachiasmatic nucleus perturbs rhythmicity of neuroactivity in prefrontal cortex

Individuals within the amyotrophic lateral sclerosis and frontotemporal dementia disease spectrum (ALS/FTD) often experience disruptive mental behaviors and sleep-wake disturbances. The hallmark of ALS/FTD is the pathological involvement of TAR DNA-binding protein 43 (TDP-43). Understanding the role of TDP-43 in the circadian clock holds promise for addressing these behavioral abnormalities. In this study, we unveil TDP-43 as a pivotal regulator of the circadian clock. TDP-43 knockdown induces intracellular arrhythmicity, disrupts transcriptional activation regulation, and diminishes clock genes expression. Moreover, our experiments in adult mouse reveal that TDP-43 knockdown, specifically within the suprachiasmatic nucleus (SCN), induces locomotor arrhythmia, arrhythmic c-Fos expression, and depression-like behavior. This observation offers valuable insights into the substantial impact of TDP-43 on the behavioral aberrations associated with ALS/FTD. In summary, our study illuminates the significance of TDP-43 in circadian regulation, shedding light on the circadian regulatory mechanisms that may elucidate the pathological underpinnings of ALS/FTD.

APOE Genotype, ApoE Plasma Levels, Lipid Metabolism, and Cognition in Monozygotic Twins with, at Risk of, and without Affective Disorders

Background: Lipids influence brain function and mental health. Understanding the role of apolipoproteins in affective disorders could provide valuable insights and potentially pave the way for novel therapeutic approaches. Methods: We examined the apolipoprotein E genotype and ApoE-levels, lipid profiles, and the correlation with cognition in 204 monozygotic (MZ) twins with unipolar or bipolar disorder in remission or partial remission (affected, AT), their unaffected co-twins (high-risk, HR), and twins with no personal or family history of affective disorder (low-risk, LR). Results: The APOE genotype was not associated with affective disorders. No significant group differences in ApoE levels were found between the three risk groups. Post hoc analysis group-wise comparisons showed higher ApoE levels in the AT than HR twins and in the concordant AT twin pairs relative to the discordant twin pairs. Within the discordant twin pairs, higher ApoE levels were observed in the affected twins (AT = 39.4 mg/L vs. HR = 36.8 mg/L, p = 0.037). Limitations: The present study could benefit from a larger sample size. We did not assess dietary habits. Conclusions: The results did not support our main hypothesis. However, exploratory post hoc analysis suggests a role for plasma ApoE and triglycerides in affective disorders. Future research is needed.

Behavioral variant frontotemporal dementia associated with GRN and ErbB4 gene mutations: a case report and literature review

OBJECTIVE

To report the clinical manifestation and genetic characteristics of a patient having frontotemporal dementia (FTD) with abnormal behavior and unstable walking.

METHODS

The clinical and imaging features of a patient who was eventually diagnosed with FTD were analyzed. The patient's neuropsychological, PET-CT, electromyography, and genetic data were collected. Furthermore, the patient's blood samples were examined for FTD-related genes.

RESULTS

The patient was a 52-year-old man with hidden onset. The symptoms progressed gradually, presenting with abnormal behaviors, including repeated shopping, taking away other people's things, constantly eating snacks, and frequently calling friends at night. The patient also exhibited executive dysfunction, such as the inability to cook and multiple driving problems, e.g., constantly deviates from his lane while driving. In addition, the patient showed personality changes such as irritability, indifference, and withdrawal, as well as motor symptoms, including unstable walking and frequent falls when walking. Brain magnetic resonance imaging revealed hippocampal sclerosis along with widening and deepening of the bilateral temporal lobe sulcus. Brain metabolic imaging via PET-CT demonstrated decreased metabolism in the bilateral prefrontal lobe, with the abnormal energy metabolism indicating FTD. Lastly, blood sample analysis detected mutations in the amyotrophic lateral sclerosis (ALS)-related GRN gene c.1352C > T (p.P451L) and ErbB4 gene c.256 T > C (p.Y86H).

CONCLUSION

This is the first case of heterozygous mutations in the GRN and ErbB4 genes in FTD alone. The GRN and ErbB4 genes are likely to be important in the pathogenesis of FTD, expanding the common genetic profile of ALS and FTD.

Narcissistic Personality Disorder as Prodromal Feature of Early-Onset, GRN-Positive bvFTD: A Case Report

Background

Behavioral variant frontotemporal dementia (bvFTD) typically involves subtle changes in personality that can delay a timely diagnosis.

Objective

Here, we report the case of a patient diagnosed of GRN-positive bvFTD at the age of 52 presenting with a 7-year history of narcissistic personality disorder, accordingly to DSM-5 criteria.

Methods

The patient was referred to neurological and neuropsychological examination. She underwent 3 Tesla magnetic resonance imaging (MRI) and genetic studies.

Results

The neuropsychological examination revealed profound deficits in all cognitive domains and 3T brain MRI showed marked fronto-temporal atrophy. A mutation in the GRN gene further confirmed the diagnosis.

Conclusions

The present case documents an unusual onset of bvFTD and highlights the problematic nature of the differential diagnosis between prodromal psychiatric features of the disease and primary psychiatric disorders. Early recognition and diagnosis of bvFTD can lead to appropriate management and support for patients and their families. This case highlights the importance of considering neurodegenerative diseases, such as bvFTD, in the differential diagnosis of psychiatric disorders, especially when exacerbations of behavioral traits manifest in adults.

Risk factors of frontotemporal dementia compared with Alzheimer disease: Single psychiatric hospital-based research in Japan

AIM

The objective of this study was to reveal risk factors for incident of frontotemporal dementia (FTD) compared with Alzheimer disease (AD) in Japan.

METHOD

Fifty consecutive subjects diagnosed with FTD according to the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) under 75 years old were included retrospectively. As a control group, 48 subjects who were diagnosed with AD according to the DSM-5 and matched by age, sex, educational history, and Mini-Mental State Examination were also included. In order to examine the distinctive risk factors of FTD, we compared the relationship between symptomatologic features, Clinical Dementia Rating, clinical factors, and sociopsychological factors in the two groups.

RESULT

Patients with FTD were more likely than patients with AD to have meticulous premorbid personality and less likely to have a history of diabetes than patients with AD. Although the regression analysis was not significant, a history of psychiatric disorders tends to affect the incidence of FTD.

CONCLUSIONS

These findings regarding the risk of FTD are expected to lead to early diagnosis and care of FTD. Geriatr Gerontol Int 2023; 23: 932-937.

Understanding Mental Health Issues in Different Subdomains of Social Networking Services: Computational Analysis of Text-Based Reddit Posts

BACKGROUND

Users increasingly use social networking services (SNSs) to share their feelings and emotions. For those with mental disorders, SNSs can also be used to seek advice on mental health issues. One available SNS is Reddit, in which users can freely discuss such matters on relevant health diagnostic subreddits.

OBJECTIVE

In this study, we analyzed the distinctive linguistic characteristics in users' posts on specific mental disorder subreddits (depression, anxiety, bipolar disorder, borderline personality disorder, schizophrenia, autism, and mental health) and further validated their distinctiveness externally by comparing them with posts of subreddits not related to mental illness. We also confirmed that these differences in linguistic formulations can be learned through a machine learning process.

METHODS

Reddit posts uploaded by users were collected for our research. We used various statistical analysis methods in Linguistic Inquiry and Word Count (LIWC) software, including 1-way ANOVA and subsequent post hoc tests, to see sentiment differences in various lexical features within mental health-related subreddits and against unrelated ones. We also applied 3 supervised and unsupervised clustering methods for both cases after extracting textual features from posts on each subreddit using bidirectional encoder representations from transformers (BERT) to ensure that our data set is suitable for further machine learning or deep learning tasks.

RESULTS

We collected 3,133,509 posts of 919,722 Reddit users. The results using the data indicated that there are notable linguistic differences among the subreddits, consistent with the findings of prior research. The findings from LIWC analyses revealed that patients with each mental health issue show significantly different lexical and semantic patterns, such as word count or emotion, throughout their online social networking activities, with P<.001 for all cases. Furthermore, distinctive features of each subreddit group were successfully identified through supervised and unsupervised clustering methods, using the BERT embeddings extracted from textual posts. This distinctiveness was reflected in the Davies-Bouldin scores ranging from 0.222 to 0.397 and the silhouette scores ranging from 0.639 to 0.803 in the former case, with scores of 1.638 and 0.729, respectively, in the latter case.

CONCLUSIONS

By taking a multifaceted approach, analyzing textual posts related to mental health issues using statistical, natural language processing, and machine learning techniques, our approach provides insights into aspects of recent lexical usage and information about the linguistic characteristics of patients with specific mental health issues, which can inform clinicians about patients' mental health in diagnostic terms to aid online intervention. Our findings can further promote research areas involving linguistic analysis and machine learning approaches for patients with mental health issues by identifying and detecting mentally vulnerable groups of people online.

Mania-related effects on structural brain changes in bipolar disorder - a narrative review of the evidence

Cross-sectional neuroimaging studies show that bipolar disorder is associated with structural brain abnormalities, predominantly observed in prefrontal and temporal cortex, cingulate gyrus, and subcortical regions. However, longitudinal studies are needed to elucidate whether these abnormalities presage disease onset or are consequences of disease processes, and to identify potential contributing factors. Here, we narratively review and summarize longitudinal structural magnetic resonance imaging studies that relate imaging outcomes to manic episodes. First, we conclude that longitudinal brain imaging studies suggest an association of bipolar disorder with aberrant brain changes, including both deviant decreases and increases in morphometric measures. Second, we conclude that manic episodes have been related to accelerated cortical volume and thickness decreases, with the most consistent findings occurring in prefrontal brain areas. Importantly, evidence also suggests that in contrast to healthy controls, who in general show age-related cortical decline, brain metrics remain stable or increase during euthymic periods in bipolar disorder patients, potentially reflecting structural recovering mechanisms. The findings stress the importance of preventing manic episodes. We further propose a model of prefrontal cortical trajectories in relation to the occurrence of manic episodes. Finally, we discuss potential mechanisms at play, remaining limitations, and future directions.

Demência Frontotemporal e Mania: As Dificuldades do Diagnóstico Diferencial

A variante comportamental da demência frontotemporal partilha semelhanças na apresentação com a fase maníacada perturbação bipolar que podem levar a dificuldades no diagnóstico. De forma a exemplificar estas dificuldades, os autores apresentam um caso clínico exemplificativo das mesmas.Um homem de 54 anos, foi admitido por elação do humor, hiperfamiliaridade, heteroagressividade, desinibiçãodo comportamento e ideação delirante persecutória. Não tinha antecedentes psiquiátricos de relevo além de um internamento recente por quadro clínico semelhante. Posteriormente, verificou tratar‐se de humor moriático, sinal frequentemente associado a lesões do lobo frontal. A SPECT mostrou compromisso da perfusão nas regiões frontais e temporais.A interpretação de sinais como o humor moriático como elação do humor, levou ao diagnóstico inicial de episódio maníaco. Avaliações posteriores mostraram tratar-se de uma demência frontotemporal. O conhecimento aprofundado das diferenças de apresentação pode evitar o erro diagnóstico e o atraso do tratamento.

[Effects of lithium, valproic acid, carbamazepine and antipsychotic agents on cognition in bipolar disorders-A systematic review]

BACKGROUND

Until now the long-term consequences of the medical treatment for bipolar disorder have barely been examined, especially the consequences with respect to cognitive impairment and dementia. Some studies show signs that some treatment options have a better effect on the brain than others. This review summarizes the current state of research.

OBJECTIVE

The effects of long-term consequences of lithium, valproic acid, carbamazepine and antipsychotic agents on the development of dementia or cognitive impairments in patients with bipolar disorder were investigated.

METHODS

A systematic literature search was carried out in the PubMed data base from May to July 2022.

RESULTS

The majority of studies showed that lithium has a neuroprotective effect and can lower the risk of developing dementia, whereas an increased risk was found in patients taking valproic acid. There are only very few studies that deal with antipsychotic medication and the long-term consequences concerning dementia.

CONCLUSION

Lithium should be recommended for the long-term treatment of bipolar disorder. Valproic acid should not or carefully be used as it can affect the risk of developing dementia. With respect to antipsychotics there is no recommendation as more studies are needed to evaluate the long-term consequences.

Biological basis and psychiatric symptoms in frontotemporal dementia

Frontotemporal dementia is a neurodegenerative disease characterized by focal degeneration of the frontal and temporal lobes, clinically presenting with disinhibited behavior, personality changes, progressive non-fluent aphasia and/or impaired semantic memory. Research progress has been made in re-organizing the clinical concept of frontotemporal dementia and neuropathological classification based on multiple accumulating proteins. Alongside this progress a list of genetic mutations or variants that are causative or increase the risk of frontotemporal dementia have been identified and some of these gene products are extensively studied. However, there are still a lot of points that need to be overcome, including lack of specific diagnostic biomarker which enable antemortem diagnosis of underlying neurodegenerative process, and lack of disease modifying therapy which could prevent disease progression. Early and precise diagnosis of frontotemporal dementia is urgently required. In this context, how to define prodromal frontotemporal dementia and early differential diagnosis from primary psychiatric disorders are also important issues. In this review we will summarize and discuss current understanding of biological basis and psychiatric symptoms in frontotemporal dementia.