Olfactory identification, cognition, depressive symptoms, and 5-year mortality in patients with subjective cognitive decline, mild cognitive impairment, and Alzheimer's disease.

OBJECTIVE: An association between odor and cognitive impairment has been shown in many studies. The objective of the present hospital-based, single-center retrospective study was to assess the impact of odor impairment on the mortality of patients with Alzheimer's disease (AD), subjective cognitive decline (SCD), and mild cognitive impairment (MCI). METHODS: Odor function was measured by Sniffin Sticks (Burghart Messtechnik, Holm, Germany) and the assessment of self-reported olfactory functioning and olfaction-related quality of life (ASOF) test. Cognitive performance was assessed by an extensive neuropsychological test battery, symptoms of depression were diagnosed with the Geriatric Depressive Scale (GDS). The influence of demographic factors such as gender, age, and education were examined. RESULTS: Although the univariate analyses and pairwise post hoc comparison showed significant differences for some of the olfactory performance tests/subtests, the multivariate models showed no association between olfactory test performance and mortality among patients with cognitive impairment. "Attention," a domain of the Neuropsychological Test Battery Vienna (NTBV), as well as depressive symptoms, gender, and age, showed a significant influence on the mortality of the patient group. CONCLUSION: Lower olfactory performance showed no impact on mortality. However, decreased cognitive function of "Attention" can be considered as an influential predictor for mortality.

Amphetamine-Induced Dopamine Release Predicts 1-Year Outcome in First-Episode Psychosis: A Naturalistic Observation.

BACKGROUND AND HYPOTHESIS: The dopamine theory of schizophrenia suggests that antipsychotics alleviate symptoms by blocking dopamine D2/3 receptors, yet a significant subset of patients does not respond adequately to treatment. To investigate potential predictors, we evaluated d-amphetamine-induced dopamine release and 1-year clinical outcomes in 21 antipsychotic-naive patients with first-episode schizophrenia. STUDY DESIGN: Twenty-one antipsychotic-naive patients (6 female) underwent dopamine D2/3 receptor radioligand [11C]-(+)-PHNO positron emission tomography. For estimating dopamine release, scans were performed with and without d-amphetamine pretreatment. The Positive and Negative Syndrome Scale was performed at regular intervals over 1 year while receiving treatment in a naturalistic setting (Clinical Trial Registry: EUDRACT 2010-019586-29). STUDY RESULTS: A group analysis revealed no significant differences in d-amphetamine-induced dopamine release between patients with or without clinically significant improvement. However, d-amphetamine-induced dopamine release in ventral striatum was significantly associated with reductions in positive symptoms (r = 0.54, P = .04; uncorrected P-values); release in globus pallidus correlated with a decrease in PANSS negative (r = 0.58, P = .02), general (r = 0.53, P = .04), and total symptom scores (r = 0.063, P = .01). Higher dopamine release in substantia nigra/ventral tegmental area predicted larger reductions in general symptoms (r = 0.51, P = .05). Post-amphetamine binding in putamen correlated positively with negative symptom scores at baseline (r = 0.66, P = .005) and throughout all follow-up visits. CONCLUSIONS: These exploratory results support a relationship between d-amphetamine-induced dopamine release and the severity and persistence of symptoms during the first year of psychosis.