A unique increase in prefrontal gray matter volume in hoarding disorder compared to obsessive-compulsive disorder

Glutamatergic neurons and GABAergic neurons of medial prefrontal cortex control hoarding-like behavior

Hoarding disorder (HD) is a chronic disease that begins early in life and does not remission unless timely treated. A large number of factors affect the presentation of HD symptoms, including a strong possessive psychology of objects and neurocognitive functioning. However, the underlying neural mechanisms of the excessive hoarding behavior in HD are still unknown. Using viral infections and brain slice electrophysiology recordings, we found that increased glutamatergic neuronal activity and decreased GABAergic neuronal activity in medial prefrontal cortex (mPFC) accelerated the hoarding-like behavior in mice. Respectively, chemogenetic manipulation to reduce glutamatergic neuronal activity or enhance GABAergic neuronal activity could improve the hoarding-like behavioral response. These results reveal a critical role played by alterations in the activity of specific types of neurons in hoarding-like behavior, and that targeted therapies for HD may be possible by precisely modulating these types of neurons.

Abnormal white matter structure in hoarding disorder

Although preliminary neuroimaging research suggests that patients with hoarding disorder (HD) show widespread abnormal task-related activity in the brain, there has been no research on alterations in the white matter tracts in these patients. The aim of this study was to investigate the characteristics of the major white matter tracts in patients with HD. Tract-based spatial statistics were used to search for white matter tract abnormalities throughout the brain in 25 patients with HD and 36 healthy controls. Post hoc analysis of regions of interest was performed to detect correlations with clinical features. Compared with the controls, patients with HD showed decreased fractional anisotropy and increased radial diffusivity in anatomically widespread white matter tracts. Post hoc analysis of regions of interest revealed a significant negative correlation between the severity of hoarding symptoms and fractional anisotropy in the left anterior limb of the internal capsule and a positive correlation between the severity of these symptoms and radial diffusivity in the right anterior thalamic radiation. Patients with HD showed a broad range of alterations in the frontal white matter tracts, including the frontothalamic circuit, frontoparietal network, and frontolimbic pathway. The findings of this study indicate associations between frontal white matter abnormalities related to the severity of hoarding symptoms in HD and the cortical regions involved in cognitive dysfunction. The insights provided would be useful for understanding the neurobiological basis of HD.

Diogenes syndrome in dementia: a case report

BACKGROUND

Diogenes syndrome is a neurobehavioural syndrome characterised by domestic squalor, hoarding and lack of insight. It is an uncommon but high-mortality condition, often associated with dementia.

AIMS

To describe the clinical features and treatment of Diogenes syndrome secondary to behavioural variant frontotemporal dementia (bvFTD).

METHOD

We describe a case of bvFTD in a 77-year-old man presenting with Diogenes syndrome.

RESULTS

The patient's medical and psychiatric histories were unremarkable, but in recent years he had begun packing his flat with 'art pieces'. Mental state examination revealed confabulation and more structured delusions. Neuropsychological evaluation outlined an impairment in selective attention and letter verbal fluency, but no semantic impairment, in the context of an overall preserved mental functioning. Brain magnetic resonance imaging and positron emission tomography (PET) with fluorodeoxyglucose showed mild bilateral temporo-insular atrophy and hypometabolism in the left-superior temporal gyrus respectively. An amyloid PET scan and genetic analysis covering the dementia spectrum were normal. A diagnosis of bvFTD was made.

CONCLUSIONS

The clinical framing of behavioural symptoms of dementia such as hoarding poses a diagnostic challenge. This case illustrates the importance of a deeper understanding of Diogenes syndrome, leading to timelier diagnosis and effective therapeutic strategies.

A Biopsychosocial Approach to Understanding Panic Buying: Integrating Neurobiological, Attachment-Based, and Social-Anthropological Perspectives

The global COVID-19 pandemic has focused the attention of researchers, civil authority and the general public on the phenomenon of "panic buying," characterized by the excessive purchase of specific materials-particularly food and hygiene-related products-in anticipation of an expected shortage. This phenomenon has been well-documented in response to several natural and man-made disasters, but its global scope and severity in the context of COVID-19 are unprecedented. This response can negatively impact health, food security, and disease prevention efforts. Attempts to modify such behaviors are more likely to succeed if they are based on insights from both the biomedical and the social sciences. From a biological perspective, the phenomenological overlap between panic buying and psychological disorders such as hoarding disorder and compulsive buying raises the possibility of a shared neurobiological underpinning. Evolutionary models suggest that these behaviors represent an attempt to enhance individual and group survival in the face of a threatened scarcity of resources. These phenomena may be influenced by specific genetic variants which are also implicated in hoarding-related psychological disorders. From a psychological perspective, attachment theory provides a conceptual framework that serves as a bridge between prior life adversity, current deprivation, and an increased attachment to material objects. Such a framework is of relevance when considering panic buying during the COVID-19 pandemic, which has been associated with significant disruptions in attachment bonds. From a social-anthropological perspective, hoarding and related behaviors have been associated with social exclusion and rejection, as well a lack of social support. These risk factors have affected large sections of the general population in the context of the COVID-19 pandemic and the governmental responses to it. This perspective also emphasizes the symbolic significance of the hoarded objects themselves. In this paper, an attempt is made to integrate these three perspectives and thereby formulate a biopsychosocial model of panic buying in response to this global health crisis. The existing scientific literature on panic buying is examined in the light of this model. Finally, suggestions are proposed as to how this model might inform social strategies aimed at preventing or reducing panic buying.

Recent Advances in Research on Hoarding

PURPOSE OF REVIEW

The purpose of the following paper is to review recent literature trends and findings in hoarding disorder (HD). Our goal is to highlight recent research on etiology, associated features, and empirically based treatments.

RECENT FINDINGS

Recent literature has added support for cognitive differences as a risk factor for HD; however, there is evidence that individuals with HD may overestimate their level of cognitive impairment. Several associated features have been highlighted in recent studies, including emotion regulation, intolerance of uncertainty and distress intolerance, and attachment. Finally, several psychotherapeutic treatments for hoarding have been recently validated, including group-based therapy and treatments using the cognitive-behavioral model. Although recent research demonstrates that hoarding can be effectively treated with available psychotherapeutic modalities, the effectiveness of current treatments is not as robust as that for other psychiatric disorders and more work is needed in treatment precision.

Pathophysiology and treatment of hoarding disorder

Hoarding disorder (HD) is a newly listed disease in the new category of Obsessive-Compulsive and Related Disorders in the DSM-5. Patients with HD find it difficult to discard possessions regardless of their actual value and to organize those things. As a result, the possessions overflow the living space and hinder living functions. Though the hoarding symptom had been regarded as a subtype of obsessive-compulsive disorder (OCD) to date, recent studies have revealed many differences in clinical characteristics, including onset, course, degree of insight, and treatment responses, between hoarding and other subtypes. Moreover, several neuroimaging studies have found specific changes of brain structure and function in OCD patients with hoarding symptoms compared to patients with non-hoarding OCD. Meanwhile, strategies for treatment of HD have not been standardized. At present, psychological treatment using cognitive behavioral therapy techniques has a certain effect. In this review, we outline the pathophysiology and treatment of HD.

Pharmacotherapy for Hoarding Disorder: How did the Picture Change since its Excision from OCD?

This brief review deals with the various issues that contributed to the creation of the new Diagnostic and Statistical Manual condition of hoarding disorder (HD) and attempts at reviewing its pharmacotherapy. It appears that after the newly founded diagnosis appeared in the literature as an autonomous entity, distinct from obsessive-compulsive disorder, drug trials are not being conducted and the disorder is left in the hands of psychotherapists, who on their part, report fair results in some core dimensions of HD. The few trials on HD specifically regard the serotonin-noradrenaline reuptake inhibitor venlafaxine, and, possibly due to the suggestion of a common biological background of HD with attention-deficit/hyperactivity disorder, the psychostimulant methylphenidate and the noradrenaline reuptake inhibitor atomoxetine. For all these drugs, positive results have been reported, but the evidence level of these studies is low, due to small samples and non-blind designs. Regretfully, there are currently no future studies aiming at seriously testing drugs in HD.