Rationale: The relationship between unexplained or refractory chronic cough (URCC) and mental health disorders (MHD) is not well understood. Therefore, we aimed to review the clinical characteristics of URCC patients with and without anxiety and/or depression, as well as patient outcomes on pregabalin therapy.  

Methods: 50 consecutive URCC patients at Montfort Hospital (Canada) were assessed; half had a diagnosis of anxiety and/or depression. Patients were prescribed pregabalin 75 mg oral qhs for 4 weeks, followed by 75 mg bid. We reviewed demographic data, medical diagnoses, prior cigarette smoking, and cough duration. Leicester Cough Questionnaire (LCQ) was completed at baseline and after 3 months of therapy. T-test and chi-square test were performed for the comparison of clinical characteristics and responses to pregabalin.

Results: 33 patients were female; mean age was 63 years. Mean BMI was 31. 28 subjects were categorized as unexplained cough and 22 refractory. 22 were ex-smokers. Mean cough duration was 54 months. Patients with MHD were younger (59 vs 67, p=0.02); no significant relationship was identified with gender, BMI, category or duration of cough, smoking history, or baseline LCQ total score (p>0.05). 28 subjects reported a LCQ total score improvement, evenly split between both groups. Among patients with MHD, responders to pregabalin were more likely to have refractory cough than unexplained (p=0.04).

Conclusions: MHD are common in URCC patients, but most clinical characteristics were similar to patients without MHD. We identified having refractory cough versus unexplained as a predictor of response to pregabalin in patients with MHD.