ASI-3 = Anxiety Sensitivity Index-3; DERS = Dysfunctional Emotional Regulation Scale; EDN = Experienced Deviation from Normal State Scale; GAD = generalized anxiety disorder; GAD-Q-IV = Generalized Anxiety Disorder Questionnaire 4th edition; ITT = intention-to-treat; MAAS = Mindful Attention and Awareness Scale; MADRS-S = Montgomery-Asberg Depression Rating Scale; OASIS = Overall Anxiety Severity and Impairment Scale; PANAS-X = Positive and Negative Affect Schedule Expanded Form; PHG-9 = Patient Health Questionnaire 9-item depression scale; PSQI = Pittsburg Sleep Quality Index; PSWQ = Penn State Worry Questionnaire; PTSD = post-traumatic stress disorder; RCT = randomized controlled trial; REST = Reduced Environmental Stimulation Therapy; SD = standard deviation; SDS = Sheehan Disability Scale; STAI = State-Trait Anxiety Inventory; VAS = visual analogue scale.

Note that this table has not been copy-edited.

The ASI-3 is an 18-item questionnaire with questions answered using a 4-point scale. The total ASI scores can range from 0 to 72. Healthy North Americans have a mean ASI-3 total score of 12.8 (SD = 10.6). Patients with anxiety and depression commonly have a total ASI score around 30.

The OASIS is a 5-item questionnaire, which is a continuous measure of anxiety severity and impairment over the past week. Each item is rated on a 5-point scale and the ratings are summed to obtain a total score ranging from 0 to 20. A cut-score of 8 has been shown to correctly classify 87% of individuals as having a current anxiety diagnosis.

The PHQ-9 is a 9-item measure for assessing the severity of depressive symptoms over the past 2 weeks. Scores of 1 to 4 are considered indicative of minimal depression, 5 to 9 mild depression, 10 to 14 moderate depression, 15 to 19 moderately severe depression, and 20 to 27 severe depression.

The SDS assesses how much the respondent’s mental health issues are perceived to have affected their daily activities in 3 functional domains: work/school, social/leisure activities, and family life/home responsibilities. Total disability scores range between 0 to 30, with scores ≥ 5 signifying impairment. Significant impairment in functioning in patients with anxiety disorders has been shown to be associated with mean total disability scores between 14 and 18.

Watching a nature documentary from the BBC Planet.

STAI is a 20-item self-report questionnaire designed to assess an individual’s level of anxiety at the present moment with total scores ranging from 20 to 80; higher scores mean higher levels of anxiety.

Measured on a 100-point VAS scale, from 0 (Not at all relaxed or no relaxation) to 100 (Extremely relaxed or the most relaxed I have ever felt).

Measured on a 100-point bipolar valence scale ranging from −50 (Extremely Unpleasant) to + 50 (Extremely Pleasant), with the slider starting in the middle of the scale at 0 (Neutral).

Measured using the PANAS-X, which is commonly used to measure mood. The scale has participants rate how calm, relaxed, and at ease they feel at the present moment using a 5-point Likert-type response scale, ranging from 1 (Very slightly or not at all) to 5 (extremely).

The 9-item MADRS-S is a Swedish self-reported assessment of depressive symptoms. The total score ranges between 0 and 54. Cut-off values have been set at: 0 to 6 = no depression; 7 to 19 = mild depression; 20 to 34 = moderate depression; and 34 or higher = severe depression.

The 16-item PSWQ is used to assess pathological worry. The instrument has a strong ability to differentiate patients with GAD from other anxiety disorders. Total scores range between 16 and 80. The cut-off score of 45 or higher indicates GAD.

The 9-item GAD-Q-IV is a self-reported measure assessing the severity of GAD as defined by the 4th edition of the Diagnostic and Statistical Manual. The measure is used as a continuous variable and the total score ranges between 0 and 12. A cut-off point of 5.7 or higher has been suggested to yield the optimal ratio between sensitivity and specificity for identifying severe GAD.

The 19-item PSQI is used to assess subjective sleep quality. The instrument measures sleep disturbance during the previous month. The total score ranges between 0 and 21 and distinguishes between good and poor sleep, where a score of 5 or higher indicates poor-quality sleep.

The 36-item DERS is a self-reported measure assessing emotion regulation difficulties. The total score ranges between 36 and 180. Higher scoring indicates greater difficulties in emotion regulation.

The 15-item MAAS is a self-reported measure of trait mindfulness. It assesses the level of open and receptive attention to and awareness of ongoing experience. The score ranges from 1 to 6. Higher scoring indicates greater mindfulness.

The EDN is a Swedish 29-item self-reported measure specifically designed to be used in floatation-REST experiments. It assesses the degree of relaxation and deviation from normal state experience during the flotation session. Each item is graded on VAS ranging from 0 to 100. A score of 30 on EDN at the first floatation session, and a score of 40 at the subsequent floatation sessions, is considered an indication of typical treatment response, in comparison with resting on a bed in a dark quiet room, which generally gives a score of 15.