stand-alone therapy for chronic insomnia" since "recent evidence shows that it is no longer supported as a single-component therapy". They further recommend educating clinicians and patients to avoid the recommendation of sleep hygiene as this can cause a "delayed implementation of effective therapies with continued or worsening insomnia symptoms" and furthermore may demotivate patients from "undergoing other treatments based on their experience using an ineffective intervention". It was also impossible to conduct a network analysis of the efficacy of specific items of sleep hygiene due to the wide heterogeneity and lack of systematic reporting of content and delivery methods. Special populations Sleep hygiene is a central component of cognitive behavioral therapy for insomnia. Specific sleep disorders may require other or additional treatment approaches, and continuing difficulties with sleep may require additional assistance from healthcare providers. College students are at risk of engaging in poor sleep hygiene and also of being unaware of the resulting effects of sleep deprivation. Because of irregular weekly schedules and the campus environment, college students may be likely to have variable sleep-wake schedules across the week, take naps, drink caffeine or alcohol near bedtime, and sleep in disruptive sleeping environments. Because of this, researchers recommend sleep hygiene education on college campuses. Harvard University, for example, requires all incoming first-year undergraduates to take a short online course on the subject before the fall semester begins. Similarly, shift workers have difficulty maintaining a healthy sleep-wake schedule due to night or irregular work hours. Shift workers need to be strategic about napping and drinking caffeine, as these practices may be necessary for work productivity and safety, but should be timed carefully. Because shift workers may need to sleep while other individuals are awake, additional sleeping environment changes should include reducing disturbances by turning off phones and posting signs on bedroom doors to inform others when they are sleeping. Due to symptoms of low mood and energy, individuals with depression may be likely to have behaviors that are counter to good sleep hygiene, such as taking naps during the day, consuming alcohol near bedtime, and consuming large amounts of caffeine during the day. In addition to sleep hygiene education, bright light therapy can be a useful treatment for individuals with depression and circadian rhythm disturbances. Not only can morning bright light therapy help establish a better sleep-wake schedule, but it also has been shown to be effective for treating depression