Efficacy and Underlying Mechanisms of Group-Based Natural Psychotherapy for Anxiety Disorder

The GAD-7 is a brief self-report questionnaire designed to assess the severity of generalized anxiety symptoms (Spitzer et al., 2006). It consists of seven items, with higher scores indicating greater severity of anxiety. Clinical cut-off scores are: 0-4 (minimal/no clinical anxiety), 5-9 (mild), 10-14 (moderate), and ≥ 15 (severe). The Chinese version of the GAD-7 has demonstrated good reliability and validity, with high internal consistency (Cronbach's α = 0.93) and satisfactory test-retest reliability (ICC = 0.71-0.87; Zhang et al., 2021).

The STAI consists of two subscales (Spielberger et al., 1970): the State Anxiety Inventory (S-Anxiety, Items 1-20) and the Trait Anxiety Inventory (T-Anxiety, Items 21-40). The S-Anxiety subscale reflects transient feelings of tension, apprehension and nervousness in response to stressors, while the T-Anxiety subscale assesses relatively stable individual differences in anxiety proneness. Both subscales use a 4-point Likert scale (total scores 20-80), with higher scores indicating higher levels of anxiety; certain items are reverse-scored. The Chinese version shows robust reliability and validity, with high internal consistency (Cronbach's α = 0.91-0.92), strong test-retest reliability (0.76-0.91), and significant correlations with the HAMA (r = 0.69-0.74; Ma et al., 2012).

The IUS is a standard self-report measure for evaluating intolerance of uncertainty (IU). This study uses the 12-item short-form (IUS-12) (Carleton, Sharpe, et al., 2007), which has been validated in Chinese populations (Zhang Y. et al., 2017). Items are rated on a 5-point scale from 0 (not at all characteristic) to 4 (entirely characteristic), with higher total scores indicating higher IU. IUS-12 includes two factors: Prospective IU (Items 1-7) and Inhibitory IU (Items 8-12), though research suggests the total score is a psychometrically sound representation of the construct (Hale et al., 2016; Shihata et al., 2018).

The QOL is a concise self-report tool for assessing individuals' overall quality of life over the past month, emphasizing subjective perceptions across key life domains. The scale comprises 7 items, with the first 6 items evaluating quality of life in physical health, mental and psychological state, economic status, work (or study) situation and interpersonal relationships with family and others, using a 5-point scoring system from "very poor" to "very good" (scored 1-5); these 6 items are summed to obtain the QOL total score. Item 7 is a self-rating of overall quality of life on a 0-100 scale, denoted as QOL score, reflecting individuals' comprehensive evaluation of their overall quality of life.