Many people experience the "winter blues", but some suffer from something more serious, seasonal affective disorder, which has a major impact on their quality of life. Light therapy is one of the interventions that is used to try to prevent it and a team of researchers from Austria and the USA published the update of their Cochrane Review in March 2019. Lead author, Barbara Nussbaumer, from the Danube University Krems in Austria, summarises the findings in this podcast.