Patients with serious psychiatric diseases (major depressive disorder (MDD), bipolar disorder (BD), and schizophrenia and psychotic disorder) often complain about sleepiness during the day, fatigue, low energy, concentration problems, and insomnia; unfortunately, many of these symptoms are also frequent in patients with Obstructive Sleep Apnea (OSA). However, existing data about the clinical appearance of OSA in Psychiatric Disease are generally missing. The aim of our study was a detailed and focused evaluation of OSA in Psychiatric Disease, in terms of symptoms, comorbidities, clinical characteristics, daytime respiratory function, and overnight polysomnography data. We examined 110 patients (56 males and 54 females) with stable Psychiatric Disease (Group A: 66 with MDD, Group B: 34 with BD, and Group C: 10 with schizophrenia). At baseline, each patient answered the STOP-Bang Questionnaire, Epworth Sleepiness Scale (ESS), Fatigue Severity Scale (FSS), and Hospital Anxiety and Depression Scale (HADS) and underwent clinical examination, oximetry, spirometry, and overnight polysomnography. Body Mass Index (BMI), neck, waist, and hip circumferences, and arterial blood pressure values were also measured. The mean age of the whole population was 55.1 ± 10.6 years. The three groups had no statistically significant difference in age, BMI, hip circumference, and systolic and diastolic arterial blood pressure. Class II and III obesity with BMI > 35 kg/m2 was observed in 36 subjects (32.14%). A moderate main effect of psychiatric disease was observed in neck (p = 0.044, η2 = 0.064) and waist circumference (p = 0.021, η2 = 0.078), with the depression group showing the lowest values, and in pulmonary function (Forced Vital Capacity (FVC, %), p = 0.013, η2 = 0.084), with the psychotic group showing the lowest values. Intermediate to high risk of OSA was present in 87.37% of participants, according to the STOP-Bang Questionnaire (≥3 positive answers), and 70.87% responded positively for feeling tired or sleepy during the day. An Apnea-Hypopnea Index (AHI) ≥ 15 events per hour of sleep was recorded in 72.48% of our patients. AHI was associated positively with male sex, schizophrenia, neck, and waist circumferences, STOP-Bang and ESS scores, and negatively with respiratory function. A large main effect of psychiatric medications was observed in waist circumference (p = 0.046, η2 = 0.151), FVC (%) (p = 0.027, η2 = 0.165), and in time spend with SaO2 < 90% (p = 0.006, η2 = 0.211). Our study yielded that patients with Psychiatric Disease are at risk of OSA, especially men suffering from schizophrenia and psychotic disorders that complain about sleepiness and have central obesity and disturbed respiratory function. Screening for OSA is mandatory in this medical population, as psychiatric patients have significantly poorer physical health than the general population and the coexistence of the two diseases can further negatively impact several health outcomes.
Keywords: bipolar disorder; major depressive disorder; obstructive sleep apnea; psychiatric disease; schizophrenia and psychotic disorder; sleep study.