Psychological impact of COVID-19 lockdown on a population with serious mental illness. A prospective cohort study.

Introduction: COVID-19 has spread worldwide since its appearance at the end of 2019. In Spain, 99-day long home confinement was set from March 15th 2020. Previous studies about events requiring situations of isolation suggested that mental health problems may occur among the general population and, more specifically, vulnerable groups such as individuals with serious mental illness (SMI). This study aims to assess the psychological effect of confinement in patients with mental illness admitted to an inpatient psychiatric unit. Method: In this longitudinal study, IDER (State-Trait Depression Inventory) and STAI (State-Trait Anxiety Inventory) questionnaires were used at two different times (at the beginning and after the lockdown) of the pandemic to evaluate the depression and anxiety symptoms, respectively, in a population of patients who had been previously admitted to the Psychiatry Unit of the Basurto University Hospital. Results: 95 participants completed the IDER questionnaire in the first measurement, with a mean score of 24.56 (SD = 8.18) for state and 23.57 (SD = 8.14) for trait. In the case of STAI, the mean score was 27.86 (SD = 15.19) for the state and 30.49 (SD = 14.71) for the trait. No differences between the first and the second time were found in anxiety and depression levels. People with personality disorders presented high levels of anxiety. Conclusions: Individuals with a personality disorder showed the highest scores in anxiety and depression. Nevertheless, strict confinement did not affect this population, despite the literature that evidences that the pandemic has worsened people's mental health with SMI.