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treatment for acne vulgaris was neither required nor prohibited. 4.3. Interventions All subjects underwent a full medical history including an acne-specific medical history. This medical history review included review of current and previous acne therapies. For female patients, a brief menstrual history was also recorded. Acne severity was assessed at a single point in time using the Global Acne Grading System (GAGS). Subjects were asked to rate the severity of their acne on the day of enrollment on a scale of 0–10 (with 0 being completely clear, and 10 being the worst acne the subject had experienced in the past six months). Depressed mood was assessed using the Clocks&Sleep 2019, 1 514 Patient Health Questionnaire 2 (PHQ-2), the impact on quality of life caused by acne was assessed with the Dermatology Life Quality Index (DLQI), and the Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality over the past month. Subjects were also given the option to complete a sleep journal which they completed daily for seven consecutive days following their in-person study visit. The journal included a subjective sleep quality rating for each night (scale of 1 to 10, with 1 being very poor and 10 being excellent). Their sleep journal was subsequently returned after its completion. 4.4. Outcome Measures The two primary outcome measures in this study are the relationship between acne severity (i.e., GAGS and self-reported) and sleep quality (PSQI and self-reported). Secondary outcomes measured included the correlation between objective or subject acne severity and depressed mood (PHQ-2) as well as the impact on quality of life (DLQI). 4.5. Statistical Analysis After descriptive analysis of sociodemographic, acne, and sleep characteristics, Pearson’s correlational coe cient was utilized for univariate comparison of linear variables in this study (including PSQI, DLQI, PHQ2, GAGS, and self-reported acne severity). Five multivariable linear regression models were then created to evaluate the relationships between continuous variables using the multiple least squares regression technique. In all models, the predictor variable was GAGS. In the first model, DLQI and PHQ2 were covariates and average sleep score was the outcome variable. In the second model, DLQI and PHQ2 were covariates and PSQI was the outcome variable. For models 3–5, self-reported acne severity was the outcome variable and PSQI, PHQ-2, and DLQI were added in succession as predictor variables. Subjects with partially missing data were excluded from analysis as appropriate. P < 0.05 was considered significant for all statistical tests. SAS 9.4 (Cary, NC, USA) was utilized for all statistical analyses. 5. Conclusions The correlation of acne severity with sleep quality is likely the consequence of a dynamic interplay of both psychiatric and pathophysiologic mechanisms. This analysis is an initial attempt to further elucidate the connection, but further research and analysis is required. Informed from this analysis, greater clarity on this subject matter will likely be gleaned from analyses with larger cohorts who have more severe acne and whose sleep quality is assessed on a more physiologic level (e.g. Conflicts of Interest: The authors declare that there was no conflict of interest regarding the publication of this article. The funding sponsors had no role in the design of the study; in the collection, analyses, or interpretation o data; in the writing of the manuscript, or in the decision to publish the results.