Background:
During the coronavirus disease 2019 (COVID-19) outbreak, several countries imposed a nation-wide lockdown, inevitably resulting in changes in lifestyles and addictive behaviors.

Objective:
The aim of this work is to investigate the impact of lockdown restrictions on smoking habits in Italy using data collected within the ‘Lost in Italy’ project.

Methods:
A cross-sectional study on a sample of 6003 subjects, representative of Italian adults aged 18–74 years was carried out. Subjects were recruited from 27 April to 3 May 2020 and respondents were asked through a web-based interview to report changes in smoking habits before the lockdown and at the time of the interview.

Results:
The prevalence of smoking decreased by 6% during the lockdown, but 16% of smokers increased their smoking intensity. In total, the lockdown increased by 9% cigarette consumption. Improvement in smoking habits during lockdown was associated with younger age, occasional smoking and unemployment. On the other hand, worsening in smoking habits was associated with mental distress, with an increase in cigarette consumption more frequently reported among those worsening their quality of life (OR=2.05; 95% CI: 1.49–2.80), reducing sleep quantity (OR=2.29; 95% CI: 1.71–3.07) and increasing anxiety (OR=1.83; 95% CI: 1.38–2.43) and depressive symptoms (OR=2.04; 95% CI: 1.54–2.71).

Conclusions:
The Italian stay-at-home order during the COVID-19 pandemic had a huge impact on smoking consumption, with an increase in cigarette consumption due to increased mental distress. These results suggest an urgent need to take into account and reduce mental health distress symptoms in smoking cessation services.