ABSTRACT: STUDY OBJECTIVE:We aimed to evaluate the association between patient-reported outcomes (PROs) and treatment regimen/standardized dose (STD), a measure of drug burden, in patients with narcolepsy type 1 (NT1)/type 2 (NT2) and idiopathic hypersomnia (IH). METHODS:Patients age 18 years or older with NT1/NT2 and IH with baseline and ? 6-month follow-up during 2008-2010 were included. Changes in PROs (Epworth Sleepiness Scale [ESS], Fatigue Severity Scale [FSS], Patient Health Questionnaire 9 [PHQ-9], total sleep time [TST]) by diagnosis, treatment regimen (monotherapy versus polytherapy, sodium oxybate [SO] use), and STD were assessed by t tests and univariable/multivariable linear regressions, adjusting for patient characteristics. RESULTS:A total of 92 patients (26 [28.3%] NT1, 27 [29.3%] NT2, 39 [42.4%] IH) were included (age 43.8 ± 14.8 years; 66 [71.7%] female). Baseline PROs suggested excessive daytime sleepiness (ESS 14.2 ± 5.2 [74% patients > 10]), significant fatigue (FSS 47.5 ± 12.9), and mild depression (PHQ-9 9.0 [4.0, 14.0] [49.4% ? 10]). At follow-up, ESS and PHQ-9 improved significantly overall and within diagnostic, monotherapy/polytherapy, and SO use groups (all P < .01). FSS improved significantly overall (P = .016), but improvements were not significant for IH, monotherapy, polytherapy, and non-SO using groups. In multivariable models, PRO changes were not significantly different between groups, but baseline STD was associated with worsening PHQ-9 across PHQ-9 change models, and ESS worsened with increasing STD at follow-up (P = .056). CONCLUSIONS:Significant improvements in sleep-related PROs were seen with pharmacotherapy use, regardless of diagnosis or treatment type, highlighting the importance of individualized prescribing decisions for this population.