Nature VR-based Sessions: The intervention lasts 5 weeks, with sessions twice weekly, 30 minutes each (10 sessions total). Participants use a single IVR headset in face-to-face groups of up to five, supervised by a PhD-level mental health expert. Completion requires attending ≥80% of sessions. The Nature-Trek VR software (Greener Games, USA) simulates diverse natural environments such as tropical islands, forests, lakes, and snow-covered landscapes. Each session features a unique environment. Sessions have three stages: (1) Training (first session only, no direct VR use), (2) Tailoring the VR nature environment, and (3) Immersion, where participants relax and experience the VR setting. Participants remain seated in comfortable chairs with wheels throughout.

Participants assigned to the waiting list arm will not receive the VR intervention during the initial 5-week study period and will continue their usual daily routines without any study-related intervention. After the study period, they will be offered the opportunity to experience a single VR session

This intervention uses the commercially available Nature-Trek VR software to immerse participants in diverse natural environments through a virtual reality headset. It is delivered face-to-face in small groups, supervised by a mental health expert, over 5 weeks with twice-weekly 30-minute sessions. The intervention includes a training session, customization of the VR nature environment, and a relaxation immersion stage. It specifically targets reduction of psychological distress and enhancement of cognitive functioning in both young and older adults.

The Positive and Negative Affect Schedule (PANAS) assess two broad domains of affect, termed Positive Affect (PA) and Negative Affect (NA). Both PA and NA represent largely independent constructs ranging from low to high levels of emotional experience . Low PA scores reflect 'sadness and lethargy' whereas high PA scores reflect 'high energy, full concentration, and pleasurable engagement'. Low NA scores describe 'a state of calmness and serenity' whereas high NA scores suggest 'subjective distress and unpleasurable engagement'. The PANAS contains 20 items that yield two subscales (PA, NA) of 10 adjectives each. Participants responded with regards to how they felt 'during the past week' on a 5-point scale from very slightly to very much. Minimum score is 20 and maximum score is 100.

It assesses the severity of depressive symptoms, specifically evaluating the intensity of depression in psychiatric and general populations aged 13 years and older. It consists of 21 items with four response options ranging from 0 (absence of the symptom) to 3 (greater severity of the symptom). It evaluates symptom severity over the past two weeks, including the day the inventory is completed. The total score ranges from 0 (no depression) to 63 (severe depression).

The State-Trait Anxiety Inventory (STAI) is a widely used self-report instrument designed to assess anxiety as both a transient emotional state (State Anxiety) and a relatively stable individual difference in anxiety proneness (Trait Anxiety). State Anxiety reflects temporary feelings of tension, nervousness, and apprehension that fluctuate over time and in response to situational stressors, whereas Trait Anxiety reflects a general tendency to perceive situations as threatening and to respond with elevated anxiety. The STAI consists of 40 items divided into two 20-item subscales (State and Trait). Participants rate the intensity or frequency of anxiety-related feelings on a 4-point Likert scale. Higher scores indicate greater levels of anxiety, with total scores ranging from 20 to 80 for each subscale.

The Mindful Attention Awareness Scale (MAAS) is a self-report questionnaire designed to assess dispositional mindfulness, defined as an individual's capacity to maintain attention and awareness of present-moment experiences in everyday life. The scale focuses on the presence or absence of mindful attention, particularly lapses in awareness and automatic pilot behaviors. The MAAS consists of 15 items rated on a 6-point Likert scale (1 = Almost Always; 6 = Almost Never). Total scores range from 15 (minimum) to 90 (maximum), with higher scores indicating greater levels of mindful attention and awareness.

The Simulator Sickness Questionnaire (SSQ) is a self-report instrument designed to assess symptoms of motion sickness or discomfort experienced during or after virtual reality exposure. The SSQ consists of 16 items grouped into three subscales: Nausea, Oculomotor, and Disorientation. Participants rate the severity of each symptom on a 4-point Likert scale: 0 (None), 1 (Slight), 2 (Moderate), 3 (Severe). Total and subscale scores are calculated according to standardized formulas, with higher scores indicating greater severity of simulator-induced discomfort.