The study examined the relationship between somatic symptom disorder (SSD) and gastroesophageal reflux disease (GERD) in 209 patients. The incidence of SSD was found in 30.14% of patients with GERD. Patients with SSD reported higher reflux symptom scores, more severe anxiety and depression, poorer sleep quality, and lower quality of life compared to patients without SSD, despite having a milder objective burden of reflux by objective measures. Independent risk factors for SSD were female gender, symptoms of laryngopharyngeal reflux, anxiety and depression. SSD partially mediated the negative effects of reflux symptoms and sleep disturbances on quality of life. The PHQ-15 screening test has demonstrated high accuracy in identifying comorbid anxiety and depression with sleep disturbances. The authors recommend screening for SSD using the PHQ-15, especially in women and patients with symptoms of laryngopharyngeal reflux.