Assessment of regional glucose metabolism by [18F]fluorodeoxyglucose position emission tomography ([18F]FDG PET) serves as a biomarker for differential diagnosis of dementia. Conversely, depressive cognitive impairment shows no abnormalities on cerebral [18F]FDG PET.

This study validates the diagnostic value of [18F]FDG PET in addition to clinical diagnosis in a real-life gerontopsychiatric clinical population.

Ninety-eight consecutive patients with depression and cognitive impairment were included. Baseline clinical diagnoses were independently established before and after disclosure of [18F]FDG PET, and dichotomised into neurodegenerative or non-neurodegenerative diseases (level 1). Subsequently, neurodegenerative cases were allocated to diagnostic subgroups (Alzheimer’s disease, Lewy body diseases, frontotemporal lobar degeneration, neurodegenerative other; level 2). An interdisciplinary, biomarker-supported consensus diagnosis after a median follow-up of 6.6 month after [18F]FDG PET served as reference. Changes of clinical diagnoses and diagnostic accuracy were assessed.

After disclosure of [18F]FDG PET, level-1 clinical diagnoses changed in 23% (95% CI 16–33%) of cases, improving the diagnostic accuracy from 72% (95% CI 62–81%) to 92% (95% CI 84–96%) (P < 0.001). [18F]FDG PET was of particular value for exclusion of neurodegenerative disease. Concerning level-2 decisions, the clinical diagnoses changed in 30% (95% CI 21–40%) of cases, increasing its accuracy from 64% (95% CI 54–74%) to 85% (95% CI 76–91%) (P < 0.001). A major fraction of incorrect level-2 diagnoses comprised Alzheimer’s disease misdiagnosed as Lewy body diseases.

[18F]FDG PET provides a significant incremental diagnostic value beyond the clinical diagnosis in depressive cognitive impairment. Thus, [18F]FDG PET should be considered in the diagnostic work-up of patients with mental disorders and cognitive impairment.

Mental illness is known to come along with a large mortality gap compared to thegeneral population and it is a risk for COVID-19 related morbidity andmortality. Achieving high vaccination rates in people with mental illness is therefore important. Reports are conflicting on whether vaccination rates comparable to those of the general population can be achieved and which variables represent risk factors for nonvaccination in people with mental illness.

The COVID Ψ Vac study collected routine data on vaccination status, diagnostic groups, sociodemographics, and setting characteristics from in- and day-clinic patients of 10 psychiatric hospitals in Germany in August 2021. Logistic regression modeling was used to determine risk factors for nonvaccination.

Complete vaccination rates were 59% (n = 776) for the hospitalized patients with mental illness versus 64% for the regionally and age-matched general population. Partial vaccination rates were 68% (n = 893) for the hospitalised patients with mental illness versus 67% for the respective general population and six percentage (n = 74) of this hospitalized population were vaccinated during the hospital stay. Rates showed a large variation between hospital sites. An ICD-10 group F1, F2, or F4 main diagnosis, younger age, and coercive accommodation were further risk factors for nonvaccination in the model.

Vaccination rates were lower in hospitalized people with mental illness than in the general population. By targeting at-risk groups with low-threshold vaccination programs in all health institutions they get in contact with, vaccination rates comparable to those in the general population can be achieved.