2026 ECNP Congress

PS01-1132

Premorbid psychiatric history and neuropsychiatric symptoms in dementia subtypes

Kerime Akyol Sümer — D. Öz, E. Bora · Tatvan State Hospital, Department of Psychiatry, Bitlis, Türkiye

2026 ECNP Congress

Background

Psychiatric disorders are increasingly recognised as risk factors for dementia; however, their role in affecting clinical features among dementia subtypes remains unclear [1], [2]. Most studies rely on registry-based data and focus on overall incidence rather than subtype-specific clinical heterogeneity [3]. Moreover, the extent to which psychiatric history shapes neuropsychiatric symptom profiles independently of disease severity has received limited attention. We aimed to determine whether premorbid psychiatric history is differentially associated with dementia subtype profiles and whether it independently contributes to neuropsychiatric symptom burden beyond disease severity.

Methods

A total of 116 patients with dementia were included: 54 Alzheimer’s disease (AD; typical or atypical) and 62 non-Alzheimer dementias (non-AD; Lewy body–related, frontotemporal dementia–related, or vascular). Within AD, additional comparisons were performed by age at symptom onset (early-onset vs. late-onset, cutoff 65 years). Diagnoses were established using internationally accepted consensus criteria, supported by neuroimaging, biomarkers, and longitudinal clinical data. Psychiatric history was assessed using a structured clinician-administered interview based on DSM-5 criteria, incorporating patient, informant, and medical record data. A five-year temporal cutoff prior to dementia onset was applied to distinguish premorbid from prodromal psychiatric conditions. Neuropsychiatric, cognitive, and social cognition assessments included the Neuropsychiatric Inventory Questionnaire (NPI-Q), Addenbrooke’s Cognitive Examination–Revised (ACE-R), Clinical Dementia Rating (CDR), Blessed Dementia Rating Scale–CERAD version (BDRS-CERAD), Frontal Systems Behaviour Scale (FrSBe), Edinburgh Social Cognition Test (ESCoT), and Reading the Mind in the Eyes Test (RMET). Group comparisons used standard parametric and non-parametric tests as appropriate, with CDR included as a covariate in analyses of neuropsychiatric outcomes.

Results

Lifetime psychiatric comorbidity was more frequent in the non-AD group than in the AD group (56.5% vs. 35.2%, p = 0.022). After applying the five-year cutoff, premorbid psychiatric history remained higher in non-AD dementia (50.9% vs. 27.1%, p = 0.014), whereas prodromal rates did not differ significantly (p = 0.189). Subgroup analyses revealed no significant differences within AD (typical vs. atypical) or non-AD (Lewy body–related vs. frontotemporal dementia–related) categories. Bipolar disorder was observed exclusively in the non-AD group (12.7% vs. 0%, p = 0.014), largely comprising late-onset cases. Late-onset psychiatric disorders were also more prevalent in non-AD dementia (17.7% vs. 1.9%, p = 0.005). Within AD, early-onset patients showed higher rates of both premorbid (62.5% vs. 20.0%, p = 0.025) and prodromal (50.0% vs. 11.1%, p = 0.048) psychiatric comorbidity compared to late-onset patients. Across the full cohort, premorbid psychiatric history was associated with greater neuropsychiatric symptom burden, with higher NPI-Q total severity (p = 0.016) and caregiver distress (p = 0.002) independent of disease severity.

Conclusions

Premorbid psychiatric history appears to contribute to neuropsychiatric symptom burden in dementia independently of disease severity. Rather than representing a uniform risk factor, psychiatric history may differentially relate to dementia phenotypes, with stronger associations in non-Alzheimer dementias and early-onset Alzheimer’s disease. Late-onset psychiatric disorders may identify a clinically relevant subgroup requiring closer monitoring for emerging neurodegenerative trajectories.

References

  1. Livingston G, et al. Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission. Lancet. 2024;404(10452):572–628.
  2. Kuring JK, Mathias JL, Ward L. Risk of Dementia in persons who have previously experienced clinically-significant Depression, Anxiety, or PTSD: A Systematic Review and Meta-Analysis. J Affect Disord. 2020;274:247–261.
  3. Mo M, et al. Psychiatric Disorders Before and After Dementia Diagnosis. JAMA Netw Open. 2023;6(10):e2338080.