The present study theorized that psychological factors that complicate the headache disorder would predict a longer length of stay (los) and minimal improvement. The present study used a quasi-experimental, prospective, cross-sectional survey research design, with multiple regression analysis. Results indicated that the hypothesized model (of psychological factors that complicate the headache disorder) to predict los and minimal improvement was not significant. There were significant reductions of bpi-sf interference and severity scores after inpatient treatment, presenting a basis for further research involving comparison groups.