Delusional Disorder in Old Age: A Hypothesis-Driven Review of Recent Work Focusing on Epidemiology, Clinical Aspects, and Outcomes

A Somatic-Type Delusional Disorder Resulted in Severe Weight Loss With a Body Mass Index of 10.2: A Case Report

Weight loss is not uncommon in the field of psychiatry; however, when severe cases arise, it necessitates attention and thorough evaluation for accurate diagnosis and appropriate treatment. This report highlights the case of a 32-year-old man referred to psychiatry due to significant weight loss. The patient mentioned consuming small food portions, attributing it to an undetected stomach illness despite repeated investigations by previous treating doctors. His current weight stood at 31 kg, with a body mass index (BMI) of 10.2 kg/m². Physical examinations and laboratory investigations were otherwise within normal parameters. A somatic delusion was confirmed, and the patient has been diagnosed with a delusional disorder after excluding other possibilities. This report highlights the importance of considering delusional disorder (somatic type) as a potential diagnosis for substantial weight loss, and it records an unexpected degree of physical well-being despite a notably low BMI.

Insights into the Medical Evaluation of Ekbom Syndrome: An Overview

Ekbom syndrome, also known as delusional parasitosis (DP) or delusional infestation, is an uncommon psychiatric disorder distinguished by an enduring conviction of parasitic infestation, persisting notwithstanding the presence of medical evidence to the contrary. Primarily affecting middle-aged women, DP can manifest either as isolated psychological distress or as a component within a more intricate psychiatric framework, substantially influencing the quality of life for affected individuals. Its pathophysiological mechanism involves uncertain dopaminergic imbalances and dysfunction in the dopamine transporter system. Dermatologists often play a pivotal role in diagnosis, as patients first seek dermatological assessments of their signs and symptoms. However, DP frequently originates from underlying psychiatric disorders or medical variables, manifesting with neurological and infectious causative factors. The diagnostic complexity is attributed to patients' resolute convictions, leading to delayed psychiatric intervention. First-line DP treatment involves antipsychotics, with newer agents demonstrating promising prospects, but the lack of standardized protocols poses a significant therapeutic challenge. In this narrative review, both a comprehensive approach to this uncommon pathology and an update on the state of knowledge in this medical subfield focused on optimizing the management of DP are provided. The complexity of DP underlying its uncommon nature and the incomplete understanding of its pathophysiology highlight the need for further research through multicenter studies and multidisciplinary teams to enhance therapeutic efficacy and safety.

Overview of late-onset psychoses

BACKGROUND

Several etiologies can underlie the development of late-onset psychosis, defined by first psychotic episode after age 40 years. Late-onset psychosis is distressing to patients and caregivers, often difficult to diagnose and treat effectively, and associated with increased morbidity and mortality.

METHODS

The literature was reviewed with searches in Pubmed, MEDLINE, and the Cochrane library. Search terms included "psychosis," "delusions," hallucinations," "late onset," "secondary psychoses," "schizophrenia," bipolar disorder," "psychotic depression," "delirium," "dementia," "Alzheimer's," "Lewy body," "Parkinson's, "vascular dementia," and "frontotemporal dementia." This overview covers the epidemiology, clinical features, neurobiology, and therapeutics of late-onset psychoses.

RESULTS

Late-onset schizophrenia, delusional disorder, and psychotic depression have unique clinical characteristics. The presentation of late-onset psychosis requires investigation for underlying etiologies of "secondary" psychosis, which include neurodegenerative, metabolic, infectious, inflammatory, nutritional, endocrine, and medication toxicity. In delirium, psychosis is common but controlled evidence is lacking to support psychotropic medication use. Delusions and hallucinations are common in Alzheimer's disease, and hallucinations are common in Parkinson's disease and Lewy body dementia. Psychosis in dementia is associated with increased agitation and a poor prognosis. Although commonly used, no medications are currently approved for treating psychosis in dementia patients in the USA and nonpharmacological interventions need consideration.

CONCLUSION

The plethora of possible causes of late-onset psychosis requires accurate diagnosis, estimation of prognosis, and cautious clinical management because older adults have greater susceptibility to the adverse effects of psychotropic medications, particularly antipsychotics. Research is warranted on developing and testing efficacious and safe treatments for late-onset psychotic disorders.

Advances in the Diagnosis and Management of Psychotic Symptoms in Neurodegenerative Diseases: A Narrative Review

Background: Approximately 15% of older adults may experience psychotic phenomena. Primary psychiatric disorders that manifest with psychosis (delusions, hallucinations, and disorganized thought or behavior) account for less than half. Up to 60% of late-life psychotic symptoms are due to systemic medical or neurological conditions, particularly neurodegenerative diseases. A thorough medical workup including laboratory tests, additional procedures if indicated, and neuroimaging studies is recommended. This narrative review summarizes current evidence regarding the epidemiology and phenomenology of psychotic symptoms encountered as part of the neurodegenerative disease continuum (including prodromal and manifest stages). Results: Prodromes are constellations of symptoms that precede the onset of overt neurodegenerative syndromes. Prodromal psychotic features, particularly delusions, have been associated with an increased likelihood of receiving a neurodegenerative disease diagnosis within several years. Prompt prodrome recognition is crucial for early intervention. The management of psychosis associated with neurodegenerative diseases includes behavioral and somatic strategies, although evidence is scarce and mostly limited to case reports, case series, or expert consensus guidelines, with few randomized controlled trials. Conclusion: The complexity of psychotic manifestations warrants management by interprofessional teams that provide coordinated, integrated care.

Critical Issues in the Management of Agitation, Aggression, and End-of-Life in Delusional Disorder: A Mini-Review

Background: Compared to other psychotic disorders, there is little information about staging care in delusional disorder (DD). Unlike schizophrenia, this is a disorder that begins in middle age, a time at which chronic medical comorbidities have already begun to impact global functioning. With age, the combination of psychological and somatic conditions leads to new behaviours, e.g., agitation, aggression, and behaviours that require specific preventive and interventive measures. With further age, knowledgeable end-of-life care becomes necessary for this population. Aim: The aim of this article was to review existing evidence on the management of these successive phases. Methods: We conducted a narrative review using PubMed and ClinicalTrials.gov and searched for the following terms: (agitation OR aggressivity OR aggression OR palliative OR "end-of-life") AND ("delusional disorder"). Results: We found that the literature was sparse. Existing evidence suggests that medical causes are frequently at the root of agitation and aggression. With respect to management, de-escalation strategies are generally preferred over pharmacotherapy. Specific delusional syndromes, e.g., de Clérambault, Othello, Capgras, Fregoli, as well as folie à deux, are associated with aggression. The somatic subtype of DD is the one most often requiring palliative care at the end of life. Conclusions: We conclude that insufficient attention has been given to the care needs of the accelerated aging process in DD.

Collaboration between Psychiatrists and Other Allied Medical Specialists for the Treatment of Delusional Disorders

Background: There is increasing evidence that individuals with psychosis are at increased risk for cardiovascular disease, diabetes, metabolic syndrome, and several other medical comorbidities. In delusional disorder (DD), this is particularly so because of the relatively late onset age. Aims: The aim of this narrative review is to synthesize the literature on the necessity for medical collaboration between psychiatrists and other specialists. Methods: A non-systematic narrative review was carried out of papers addressing referrals and cooperation among specialists in the care of DD patients. Results: Psychiatrists, the primary care providers for DD patients, depend on neurology to assess cognitive defects and rule out organic sources of delusions. Neurologists rely on psychiatry to help with patient adherence to treatment and the management of psychotropic drug side effects. Psychiatrists require ophthalmology/otolaryngology to treat sensory deficits that often precede delusions; reciprocally, psychiatric consults can help in instances of functional sensory impairment. Close collaboration with dermatologists is essential for treating delusional parasitosis and dysmorphophobia to ensure timely referrals to psychiatry. Conclusions: This review offers many other examples from the literature of the extent of overlap among medical specialties in the evaluation and effective treatment of DD. Optimal patient care requires close collaboration among specialties.