In a recent article in this journal, Shevlin et al. (2021) reported that the mental health of adults in the UK, who were surveyed as part of the COVID-19 Psychological Research Consortium (C19PRC) study during the first year of the COVID-19 pandemic, could be best described in terms of five profiles. They found that a small proportion of people (~5%) experienced increased symptoms of depression/anxiety and Covid-19 related posttraumatic stress disorder (C19-PTSD), a slightly higher proportion (~6-8%) experienced decreased symptoms of both, and the rest (> ~80%) experienced no major changes across the year. These results are consistent with findings from two meta-analytic reviews of changes in population mental health from before and after the outbreak of COVID-19 (Prati & Mancini, 2021; Robinson et al., 2021). These studies showed that there was a small increase in symptoms of mental ill health in the first weeks of the pandemic, followed by a return to pre-pandemic levels by May 2020. Here we report results from the now completed C19PRC study in Ireland that assessed the mental health of adults at five points during the first year of the pandemic. Specifically, we present findings on (1) what proportion of adults met criteria for depression, anxiety, and/or C19-PTSD at each assessment, and (2) if, and how, symptoms and prevalence estimates of these disorders changed during the first year of the pandemic.