Delusional Disorder and Psychotic Phenomena

Delusional disorder is a distinct psychiatric condition characterised by the persistent presence of one or more non-bizarre delusions lasting at least one month, without the prominent cognitive decline or disorganised speech and behaviour typical of schizophrenia. Psychotic phenomena encompass a broader range of experiences in which individuals may lose contact with reality, including hallucinations, formal thought disorder and severe disruptions in perception. In delusional disorder, the delusions often centre on themes such as persecution, jealousy, somatic preoccupations or erotomania, yet patients may otherwise appear functional in daily life. The disorder usually emerges in middle to late adulthood and shows a variable course, sometimes with periods of remission punctuated by relapses. Comorbid mood and anxiety symptoms, as well as risk of self-harm or aggression, underscore the need for comprehensive assessment. Advances in neuroimaging and neurocognitive testing have begun to reveal subtle alterations in executive function and memory processes, challenging the traditional notion of cognitive intactness. Genetic studies suggest modest heritability and overlap with other psychoses. Psychosocial factors, including cultural context and life transitions, can shape the content and persistence of delusions. Treatment remains a challenge due to variable response to antipsychotic medication, high rates of non-adherence and limited evidence for standardised guidelines. Collaborative care models, integrating psychiatry with neurology, primary care and allied disciplines, are increasingly recognised as essential to address medical comorbidities and optimise outcomes.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Delusional Disorder and Psychotic Phenomena publication trend

The graph below shows the total number of articles in delusional disorder and psychotic phenomena across all publications each year (not limited to Nature Index journals).

Technical terms

Delusional disorder: A psychiatric condition marked by the presence of one or more persistent, non-bizarre delusions without prominent disorganisation or cognitive decline.

Psychotic phenomena: A spectrum of symptoms indicating impaired reality testing, including delusions, hallucinations and disorganised thinking.

Erotomania: A subtype of delusional disorder characterised by the fixed belief that another person, often of higher status, is in love with the affected individual.

Antipsychotics: A class of medications that modulate neurotransmitter pathways—particularly dopamine—to alleviate psychotic symptoms.

References

1. Induced erotomania by online romance fraud - a novel form of de Clérambault’s syndrome. BMC Psychiatry (2024).
2. Seventy Years of Treating Delusional Disorder with Antipsychotics: A Historical Perspective. Biomedicines (2022).
3. Functional and clinical outcomes of delusional disorder and schizophrenia patients after first episode psychosis: a 4-year follow-up study. BMC Psychiatry (2023).
4. Deficits in Executive and Memory Processes in Delusional Disorder: A Case-Control Study. PLOS ONE (2013).
5. Collaboration between Psychiatrists and Other Allied Medical Specialists for the Treatment of Delusional Disorders. Healthcare (2022).