Participants also complete diagnostic-specific measures, quality of life and functioning measures, as well as other questionnaires related to anxiety disorders. The
Social Phobia Inventory (SPIN) [
65,
66] consists of 17 items measuring the fear, avoidance, and physiological discomfort commonly experienced by people with social anxiety disorder. Each item receives a rating from 0 to 4, with higher ratings indicating higher levels of distress associated with each statement. This questionnaire has good internal reliability, test-retest reliability, convergent validity, and a cut-of score of 19 can distinguish between patients with and without social anxiety with 79% accuracy [
65]. The
Penn State Worry Questionnaire (PSWQ) [
67,
68] is a 16-item questionnaire to assess the trait of worry, which characterizes generalized anxiety disorder (GAD). Patients are asked to rate how well statements about worry describe themselves from 1 to 5. If the statement does not describe them at all, it is given a rating value of 1, whereas a statement that is very typical of them would receive a rating value of 5. It assesses the trait of worry with high internal consistency and test-retest reliability. The
Panic Disorder Severity Scale Self Report (PDSS-SR) [
69,
70] asks respondents to indicate the severity of each of 7 dimensions of panic disorder during the last week on a scale from 0 to 4. A zero indicates that the patient did not experience the item and four indicates the most severe reaction. This self-report scale has good internal reliability, test-retest reliability and sensitivity to change [
70]. The
Mobility Inventory for Agoraphobia (MIA) [
71] assesses the frequency of agoraphobic avoidance behaviour by asking patients to evaluate their level of avoidance of 27 places or situations when alone or when with a companion. Each item is given a rating from 1 to 5 where 1 represents no avoidance and a 5 means that the place or situation is always avoided. The MIA has been proven to have excellent internal consistency, and strong convergent and discriminant validity [
71]. The
Patient Health Questionnaire (PHQ-9) [
72] is used for the assessment of the frequency of depressive symptoms with good reliability and validity. Patients indicate how many days in the last 2 weeks they have experienced any of 9 symptoms of depression with responses ranging from 0, meaning never, to 3 meaning almost every day. Scores below 10 indicate unlikely major depression while scores above 15 indicate likely major depression. The
Insomnia Severity Index [
73,
74] is a brief 7-item questionnaire assessing the severity of insomnia and associated difficulties. Each item is rated on a 0 to 4 scale, total score ranging from 0 to 28, with a higher score suggesting more severe insomnia. The instrument has been shown to have adequate internal consistency, concurrent validity documented by significant correlations with sleep diary and polysomnography measures. The
Sheehan Disability Scale [
75] is a measure that allows patients to indicate their level of disability visually, numerically, or descriptively on a scale for each of 3 life dimensions: work, social life and family life. Each item is scored from 0 being no impairment, to a 10 being extremely impaired. It is a brief rating scale that has good sensitivity and a score of 5 or higher corresponds with an increased risk of psychiatric impairment. The
EuroQoL EQ-5D [
76] is a 5-item standardised scale measuring health-related quality of life on five dimensions (e.g., mobility, self-care, anxiety/depression), each rated on 5 levels of impairment. The instrument includes a visual analogue scale to rate health from 0 to 100. The scale has excellent test-retest reliability; and good concurrent validity with the SF-36. The
Centers for Disease Control Healthy Days Measures (CDC HRQOL-4) [
77] includes one item of the perception of one’s health and three items assessing the number of days in the past 30 days when physical or mental health was not good and that activity limitations were present. The scale has demonstrated acceptable test-retest reliability and strong internal validity. The list of 21 chronic diseases from the
Disease Burden Morbidity Assessment [
78,
79] was included to document the presence of chronic conditions. The ratings of the interference of conditions on daily activities were not included. The
Mental Health Continuum Short Form (MHC-SF) [
80] consists of 14 items measuring the frequency at which respondents experience emotional, psychological, and social well-being in the past month. Items are rated from 0 (Never) to 5 (Every day). The short form of the MHC has shown excellent internal consistency, construct and discriminant validity. The
Mental Health Self-Management Questionnaire (MHSQ) [
81] assesses the use of mental health self-management strategies. It comprises 18 items rated on a 5-point Likert scale ranging from 0 (Never) to 5 (Very often), with a total maximum score of 72. The scale has satisfactory internal reliability and construct validity, adequate test–retest reliability and its convergent and concurrent validity are supported. The
Medical Outcomes Study Social Support Survey (MOS-SSS) [
82,
83] is a 6-item version of the original MOS scale which assesses the types of support and their availability on a scale from 1 (None of the time) to 5 (All of the time). The instrument has strong internal consistency and scale reliability.