Background: The emergence of the coronavirus pneumonia (COVID-19) resulted in a global pandemic. The psychological impact of an epidemic is multifaceted and acute, with long-term consequences. Methods: A cross-sectional online survey-based design was employed, assessing the psychological impact of COVID-19 on members of the Irish public during the quarantine period of COVID-19 in Ireland. Participants were invited to complete the Depression, Anxiety, and Stress Scale-21 (DASS-21) retrospectively (prior to quarantine) and during the quarantine period, as well as measures of illness perceptions, well-being, and a bespoke measure (the Effects of COVID Questionnaire, ECQ), which assessed perceptions of COVID-related stresses associated with personal concerns, caring for children, caring for aging parents, as well as gratitude. Results: A total of n = 1620 entered the survey platform, with a total of n = 847 surveys completed by members of the Irish public. Entry into COVID-19 quarantine was associated with significant increases in clinically significant symptoms of depression, stress, and anxiety. The ECQ reliably assessed a range of COVID-19-related stresses and had large and significant correlations with the DASS-21. Conclusions: The COVID-19 quarantine was associated with stresses and significant increases in symptoms of depression, anxiety, and stress in a national Irish cohort. The public require increased access to mental health services to meet this increase in COVID-19-related psychological distress.

Social cognition has a broad theoretical definition, which includes the ability to mentalise, i.e., recognise and infer mental states to explain and predict another’s behaviour. There is growing recognition of the clinical, diagnostic, and prognostic value of assessing a person’s ability to perform social cognitive tasks, particularly aspects of theory of mind, such as mentalising. One such measure of mentalising is the ‘Reading the Mind in the Eyes’ test (RMET). This systematic review and meta-analysis consider performance on the RMET, applied to people with neurodegenerative conditions in matched control studies, since its publication in 2001. Overall, this review includes 22 papers with data from N = 800 participants with neurodegenerative conditions: Alzheimer’s disease, n = 31; Parkinson’s disease, n = 221; Lewy body dementia, n = 33; motor neuron disease, n = 218; Huntington’s disease n = 80; multiple sclerosis, n = 217; and N = 601 matched typical controls. Our meta-analyses show that deficits in mentalising, as measured by the RMET, are consistently reported across neurodegenerative conditions, with participants in both early and late disease stages being affected. Social cognition is an emerging field of cognitive neuroscience requiring specific and sensitive measurement across each subdomain. Adult-based meta-normative data feature, for which future groups or individuals could be compared against, and hypotheses relating to the source of these mentalising deficits are further discussed. This review was registered with PROSPERO (CRD42020182874).