OBJECTIVES: Drug development necessitates a rigorous evaluation of cognition to assess the safety and efficacy of potential new treatments. This study aimed to identify and categorize the types of cognitive assessments commonly employed in interventional studies, specifically focusing on neurodegenerative diseases.

METHODS: A systematic search was conducted using Clinicaltrial.gov. A total of 918 studies were first retrieved across multiple indications. After excluding withdrawn studies and those conducted by sponsors other than the pharmaceutical industry, 64 studies that met the criteria for Dementia and MCI were retained.

RESULTS: Among the trials assessing cognition in Alzheimer's disease and dementias (N=40), the most frequently used cognitive performance outcome (Cog-PerfO) batteries were ADAS-Cog (N=27, 67.5%), MMSE (N=18, 45%), and RBANS (N=4; 10%). Additionally, questionnaires such as the Clinical Dementia Rating - Sum of Boxes (CDR-SOB) were also frequently used (N=13, 32.5%), with two studies using it as the sole cognitive assessment tool. In studies related to Mild Cognitive Impairment (MCI) (N=24), the CDR-SOB questionnaire (N=10; 41.6%) was the most common, followed by Cog-PerfO batteries such as ADAS-Cog (N=8; 33.3%), MMSE (N=9; 37.5%), and the Neuropsychological test battery (N=5; 20.8%). Individual tasks evaluating specific cognitive functions were also used including the Digit symbol Substitution task for processing speed (N=3; 12.5%), and the Free and Cued Selective Reminding Test (FCSRT) (N=3; 12.5%) and Wechsler Memory Scales (N=3, 12.5%) for memory. Other cognitive batteries and individual Cog-PerfOs assessing specific cognitive functions were used in both dementias and MCI, but less frequently and consistently (<10% of studies).

CONCLUSIONS: The instruments used for cognitive assessments were similar in Mild Cognitive Impairment (MCI) and moderate to severe dementia, which may reduce the sensitivity to detect subtle cognitive changes in individuals with MCI/ early onset dementia. Employing tailored tools for each condition is necessary to ensure accurate and sensitive cognitive assessments.