The study was conducted within a community-based service for individuals with Severe Mental Disorder, called the Assertive Community Treatment Team (ACT Team), located in the city of Cartagena, Spain.

The study participants were active users currently receiving care from this service.

The intervention was administered individually, and the authors based it on a review of the scientific literature on studies that evaluated the main proposed variables: quality of life, social functioning, and hope.

In general, participants selected the music they wished to listen to for each session, following the nurse's guidance, and a dialogue was then established between the participant and the nurse.

The intervention lasted approximately 20 weeks, with a weekly or biweekly frequency. The intervention consisted of 12 sessions, each lasting 45-60 minutes.

This self-administered questionnaire assesses an individual's quality of life across four domains (physical health, psychological health, social relationships, and environment). It also includes an evaluation of perceived general health and overall quality of life. The questionnaire consists of 26 items with five response options (1-5). The higher the score in each domain, the better the quality of life profile of the person being assessed.

This self-administered questionnaire assesses an individual's negative perceptions about the future and suicide risk. It consists of 20 items with true/false response options. The results indicate four levels of hopelessness: 0-3 (normal/asymptomatic), 4-8 (mild), 9-14 (moderate), and 15-20 (severe).

The self-administered version of this scale assesses seven dimensions of social functioning:

Social isolation: 0 to 3 per item, with a total score range of 0-15. Interpersonal behavior: 4 items. First, items 1 and 2 are summed; if their combined score exceeds 3, a maximum of 3 is assigned. The remaining two items are scored from 0 to 3, resulting in a total score range of 0-9.

Prosocial activities: 22 items, scored 0 to 3, total score range 0-66. Leisure: 15 items, scored 0 to 3, total score range 0-45. Independence-performance: 13 items, scored 0 to 3, total score range 0-39. Independence-competence: 13 items, scored 1 to 3, total score range 13-39. Employment/occupation: A score of up to 6 points is possible if the patient feels capable of performing some type of work and is making frequent attempts to find employment.

It includes 78 items. Higher scores consistently indicate a higher level of social functioning in each domain.

The participants completed a self-developed satisfaction survey to assess their level of satisfaction with the intervention, measured using a 5-point Likert scale ranging from 1 (very dissatisfied) to 5 (very satisfied).