COVID-19 lockdown impact on mental health in a large representative sample of Italian adults

•This is the first cross-sectional multi-disciplinary consortium study conducted in Italy on a representative sample of adults to testify the huge implications of the COVID-19 lockdown on mental health.•National-level prevalence of depressive and anxiety symptoms doubled, getting to affect more than one third of the general adult population and the use of at least one psychotropic drug – mostly anxiolytics/benzodiazepines – increased by 20%.•Women more frequently worsened their mental health, as compared to men.•A worsening in depressive symptoms was more likely observed in young, in current and former smokers, in gamblers, and in subjects reporting longer time spent outdoor and more hours of physical activity before the lockdown. The potential benefits of the COVID-19 lockdown need to be carefully weighed versus the possible impact on people's daily life and negative mental health effects.We aimed to assess the prevalence of depression, anxiety, insomnia and quality of life before and during the COVID-19 lockdown,identifying subgroups at higher risk of mental distress as a consequence of COVID-19 associated restrictions. Within the Lost in Italy project, a web-based cross-sectional study was conducted on a representative sample of 6003 Italian adults aged 18–74 recruited from April 27 to May 3, 2020, within the nation-wide stay-at-home order. The prevalence of depressive symptoms (PHQ-2 ≥ 3) increased from 14.3% before lockdown to 33.2% during lockdown, anxiety symptoms (GAD-2 ≥ 3) from 18.1% to 41.5%, insufficient sleep (≤6 h/day) from 33.7% to 41.1%, unsatisfactory sleep from 17.0% to 38.8% and unsatisfactory quality of life from 13.1% to 42.1%.Overall, 47.7% reported worsened depressive symptoms, 43.6% worsened anxiety symptoms, sleep quantity (31.5%) and quality (35.0%),and 64.1% worsened quality of life.A statistically significant relationship with all mental health outcomes considered was found for women vs. men (multivariate odds ratio,OR between 1.13 and 1.63), for current vs. never smokers (OR between 1.15 and 1.25), and with increasing physical activity (p for trend