A transdiagnostic perspective on the measurement, assessment, and treatment of cognitive impairment in neuropsychiatric disorders

Thesis

Cognitive impairment is a core feature of numerous neuropsychiatric disorders yet remains under-addressed in routine clinical care. This PhD thesis adopts a transdiagnostic perspective to explore the measurement, assessment, and treatment of cognitive impairment across diagnostic boundaries. First, brain-derived neurotrophic factor (BDNF) and metabolic syndrome were evaluated for their potential as biomarkers in clinical settings. While both showed associations with cognitive function, neither proved specific or reliable enough for routine use due to measurement limitations and high dependence on external factors. Second, the development and real-world application of the Transdiagnostic Global Impression – Psychopathology scale (TGI-P), a brief tool assessing ten transdiagnostic symptom domains, including cognition was described. In a small inpatient sample, TGI-P scores correlated well with established scales such as the PANSS, particularly for positive and manic symptoms. Cognitive and depressive symptoms were less strongly correlated but still measurable, suggesting the scale’s promise for integrating measurement-based care in psychiatry. Third, the cognitive effects of cariprazine, a third-generation antipsychotic was evaluated. A systematic review and meta-analysis indicated the potential of cariprazine as a transdiagnostic treatment for cognitive symptoms. This was further supported by findings from a 12-week observational study in patients with Huntington’s and Parkinson’s disease, where cariprazine showed promising effects on cognitive and affective symptoms. Overall, this thesis highlights the importance and challenges of addressing cognitive impairment independent from clinical diagnosis. While robust biomarkers are still lacking, practical tools like the TGI-P and emerging treatments like cariprazine may support better recognition and management of cognitive impairment in clinical practice.

Authors: Dombi, Z

• DOI: 10.5287/ora-6q47rxwwj
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Keywords: TGI-P scale; transdiagnostic approach; BDNF; cognitive impairment; cariprazine; metabolic syndrome
• Subjects: psychiatry