**2. Materials and Methods**

We conducted a cross-sectional survey among the inhabitants with chronic diseases who attended the inpatient units and outpatient clinics of the West Pomerania region in Poland from 3 May to 17 May 2020. During this period at each inpatient units and outpatient clinics, all consecutive patients who corresponded to the inclusion criteria were invited to complete a 9-item Patient Health Questionnaire (PHQ-9), 7-item Insomnia Severity Index (ISI) and a 7-item Generalized Anxiety Disorder scale (GAD-7) in Polish followed by an interview with a structured socio-demographic questionnaire. The criteria for inclusion were as follows: (1) informed consent before the survey was conducted; (2) residence in the West Pomerania region; (3) age 18 years and older. Exclusion criteria: diagnosis of mental illness. Each participant provided details regarding their basic demographic data and chronic diseases such as hypertension, diabetes mellitus, heart failure, coronary heart disease, dyslipidemia, chronic obstructive pulmonary disease and nicotinism. Each patient was also asked about the presence of Hashimoto's disease, one of the most common, if not the most common, autoimmune disease. The survey involved 879 people. All participants gave their informed consent before the survey was conducted. These participants could interrupt the survey at any time. The full confidentiality of information was ensured. Prior to the survey, the opinion of the Bioethics Committee of the Pomeranian Medical University in Szczecin was received (KB-0012/26/04/2020/Z) which conformed to the ethical guidelines of the Declaration of Helsinki.

Insomnia symptoms were assessed using the 7-item Insomnia Severity Index (ISI; range 0–28) [17–19], depression symptoms using the 9-item Patient Health Questionnaire (PHQ-9; range 0–27) [20–22], and anxiety symptoms with the 7-item Generalized Anxiety Disorder scale (GAD-7; range 0–21) [23].
