Response to the letter to the editor titled «Secondary psychotic syndromes should be excluded before assuming idiopathic digital “Folie à Trois”»

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We sincerely thank Prof. João Gama-Marques for thoughtful engagement [1] with our case series on digitally mediated shared psychotic disorder [2]. The opportunity to clarify methodological, diagnostic, and nosological aspects of our work is greatly appreciated. Our response below addresses the key concerns raised, while situating our interpretations within contemporary psychiatric literature.

On the classification of antipsychotic treatments

The correspondents note that aripiprazole is often described as a “third-generation antipsychotic” due to its partial dopamine D₂ agonism. We acknowledge this pharmacodynamic distinction. However, in many contemporary clinical contexts and guideline frameworks, aripiprazole continues to be grouped within the broader category of second-generation (atypical) antipsychotics when contrasted with first-generation agents [2]. Our use of terminology was therefore pragmatic. Importantly, this classification did not affect treatment rationale, clinical interpretation, or outcome reporting. The therapeutic response across cases was consistent with established evidence supporting dopamine-modulating agents in delusional and schizophrenia spectrum disorders [3, 4].

On ICD classification and diagnostic clarity

We agree that explicit diagnostic specifications enhance clarity. Shared psychotic disorder has historically occupied a complex nosological position. While Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition subsumed “shared psychotic disorder” under “other specified schizophrenia spectrum and other psychotic disorder”, the International Classification of Diseases 10th Revision (ICD-10) retains the entity of induced delusional disorder (F24), and ICD-11 continues to recognize related phenomena under schizophrenia spectrum conditions [5].

In our series, Case A most closely met criteria for a primary delusional disorder with persecutory themes rather than schizophrenia, given the absence of persistent negative symptoms, disorganization, or cognitive decline. Cases B and C demonstrated symptom emergence temporally linked to psychological dependence on Case A, with rapid partial remission following separation and treatment — features classically associated with induced psychosis [6]. This diagnostic reasoning aligns with prior systematic reviews showing that inducers most commonly have delusional disorder or schizophrenia spectrum conditions, while recipients exhibit suggestibility and psychological dependency [6, 7].

On exclusion of secondary psychotic syndromes

We fully concur that secondary causes must be excluded before attributing psychosis to a primary disorder. All three patients underwent comprehensive clinical evaluation, including metabolic screening, thyroid profiling, vitamin levels (with correction where indicated), substance use assessment, and neuroimaging where clinically warranted. No neurological signs, fluctuating consciousness, autonomic instability, or systemic features suggestive of autoimmune or infectious encephalitis were present. Current guidelines emphasize a probability-guided diagnostic workup, reserving extensive investigations (e.g., lumbar puncture, neuronal antibody panels) for cases with red flags or atypical features [8]. In the absence of such indicators, our evaluation was consistent with accepted standards of care [8, 9].

On the conceptualization of “digital” shared psychosis

The correspondents question whether the diagnosis of idiopathic shared psychosis may be premature. We wish to clarify that our central claim was not that the disorder was idiopathic, but that the mechanism of delusional transmission occurred in the absence of physical proximity, mediated instead by sustained digital interaction. The possible intersections have been discussed in detail in our original paper. Shared psychosis has historically required prolonged interpersonal closeness; however, emerging literature in digital psychiatry demonstrates that immersive online environments can generate comparable emotional intensity, identity fusion, and reinforcement dynamics [10]. In this sense, our report extends, rather than replaces classical models of folie à deux by proposing that psychological proximity in the digital era may functionally substitute for geographical cohabitation.

On therapeutic separation and recovery

The improvement of recipients following temporary separation from the inducer is well documented in earlier and contemporary literature [6, 11]. In our cases, structured digital abstinence during the acute phase was associated with accelerated reduction in persecutory intensity in Cases B and C. While antipsychotic medication was administered in all three cases, differential trajectories of insight recovery support classical observations that recipients often demonstrate more rapid improvement once environmental reinforcement is interrupted [11].

In conclusion, we appreciate the authors’ emphasis on rigorous differential diagnosis and nosological precision. Our intent was to contribute to the evolving understanding of how shared psychosis may manifest within digitally mediated social ecosystems. We hope this exchange stimulates further empirical research on the intersection between digital environments and psychotic phenomena.

Funding: The research was carried out without additional funding.

Conflict of interest: The author declares no conflicts of interest.

Generative AI use statement: During the preparation of this work, the authors used Grammarly tool in order to check spelling/grammar. After using this tool, the author reviewed and edited the content as needed and takes full responsibility for the content of the publication.

About the authors

Debanjan Banerjee

Author for correspondence.
Email: dr.djan88@gmail.com
ORCID iD: 0000-0001-8152-9798
Scopus Author ID: 57191832268

MBBS, MD (Psychiatry), DM (Geriatric Psychiatry), Consultant old-age psychiatrist

References

Supplementary files

Parent article DOI https://doi.org/10.17816/CP15802