Like any therapy, SLEEPexpert does not work equally well for all patients. If patients report no improvement during the program, check whether the sleep window has been consistently implemented to allow for change. Often, it turns out that the sleep window was not regularly adhered to (e.g., longer time in bed on weekends or daytime naps). As a rule of thumb, bedtime restriction should be implemented for at least 4 weeks. If there is no response after this period, possible reasons should be evaluated and further diagnostics made. This should include assessment for sleep apnea syndrome, restless legs syndrome, periodic limb movements and circadian rhythm disorders. Additionally, other somatic or psychiatric differential diagnoses should be reconsidered and specific treatments initiated if needed. According to treatment guidelines, medication can be considered in case of non-response.