The researchers definition of insomnia is based on two gold-standard instruments designed to assess the DSM criterion A4 "insomnia" required for the diagnosis of a major depressive episode. The researchers definition was made deliberately broad to capture all participants with reduced sleep in contrast to those with normal sleep or hypersomnia. It is unlikely that this definition would miss any participants experiencing impaired sleep at baseline. Furthermore, participants meeting either of these criteria would be judged to be experiencing insomnia as a symptom of depression in most other research and clinical settings. The researchers have requested for this definition that participants have impaired sleep on both the MADRS and HAMD-17 so that there is agreement between participants' self-reported insomnia (MADRS) and clinician-rated insomnia (HAMD-17). This also makes the results potentially more relevant to a clinical setting in which clinicians assess the presence of depressive symptoms including insomnia using simple questions with face validity such as those on the HAMD-17, and do not typically rely solely on patient self-report questionnaires.