FEEL-GOOD: A Multicenter Trial of a Mindfulness-Based Group Therapy in Young Adults With Early Psychosis

The primary outcome is observer-rated (blinded) total psychopathology as measured by the total score of PANSS after 4 weeks (t2). PANSS is widely used and the gold standard for psychopathological outcomes in people with psychotic disorders. It integrates positive, negative, and general psychopathological symptoms.

The PANSS is a semi-structured interview to assess positive symptoms (PANSS Positive Scale), negative symptoms (PANSS Negative Scale) and general pathology (PANSS General Psychopathology Scale) of Psychosis.

The FFMQ-D consists of 39 items forming the 5 subscales non-reactivity to inner experience, observing, acting with awareness, describing/labelling with words, and nonjudging of inner experience. Items are self-rated on a 5-point Likert-scale.

Global self-esteem will be assessed with the RSES that consists of 10 items self-rated on a 4-point Likert-scale.

Participants will complete EMA via the m-Path mobile application starting after giving informed consent and randomisation into the trial and will end seven days post-intervention. There will be one prompt per day. Each prompt will include approximately 39-46 items, depending on conditional branching. The questions will cover several domains, such as current emotional state, psychopathological symptoms, mindfulness, emotional (in-)stability, and emotion regulation skills.

The TAS-26 is the German version of the TASand consists of 26 items with the 3 subscales: Difficulties Identifying Feelings, Difficulties Describing Feelings, and Externally Oriented Thinking self-rated on a 5-point Likert-scale.

The CERQ measures cognitive coping strategies, i.e., thoughts after negative events or situations on 9 subscales (self-blame, blaming others, acceptance, refocusing on planning, positive refocusing, rumination, positive reappraisal, putting into perspective, and catastrophizing), each consisting of 4 items that are self-rated on 5-point Likert-scales.

The ERSQ consists of 27 items with 9 subscales assessing competencies that are considered essential for successful emotion regulation (i.e., attention, clarity, bodily awareness, understanding, acceptance, resilience, self-support, willingness to confront, and regulation). Self-reports are rated on a 5-point Likert-scale.

The ZUF-8 is the German version adapted for inpatients based on the Client Satisfaction Questionnaire (CSQ-8). It consists of 8 items self-rated on a 4-point Likert-scale and assesses patients' overall satisfaction with the clinical treatment received.

The WHOQOL-BREF assesses quality of life as a subjective evaluation, embedded within the individual's cultural, social, and environmental context using 26 items divided into 4 domains: physical health, psychological well-being, social relationships, and environment. Items are rated on a 5-point Likert-scale.

The PSYRATS is a semi-structured interview to assess delusions and hallucinations. It consist of 17 items assessing specific dimensions of hallucinations and delusions. Each item is observer-rated on a 5-point scale ranging from 0 (= absent) to 4 (=severe). The PSYRATS include two subscales: hallucinations with 11 items (PSYRATS-H) and delusions with 6 items (PSYRATS-D).

The CDSS is considered as the gold standard to assess depression specifically in people with schizophrenia spectrum disorders. The 9 items are observer-rated on a scale ranging from 0 (=absent) to 3 (=severe). It distinguishes between depressive symptoms, positive, negative, and extrapyramidal symptoms in adolescents and adults

The RFS is a semi-structured interview that measures performance on 4 single rating scales: working productivity, independent living, immediate social network relationships (friends and family), and extended social network relationships (other social contacts) with observer ratings from 0 (= minimal functioning) to 12 (= optimal functioning).

In the GAF scale, clinicians rate a patient's overall level of psychological, social, and occupational functioning using a single score ranging from 1 to 100. A score of 100 represents superior functioning, whereas a score of 1 indicates a persistent risk of serious harm to oneself or others, severe impairment in basic self-care, or a suicidal act with clear expectation of death.

Changes of approximately 4, 10, or 12 points have been suggested to represent clinically meaningful differences [15].

Serious adverse events are assessed and consist of suicidality, suicide attempts, death, life-threatening events or hospitalization (if patients were previously in outpatient treatment).

The self-rating questionnaire Child Trauma Questionnaire (CTQ) consists of five subscales: emotional abuse, physical abuse, sexual abuse, emotional neglect, and physical neglect, each comprising five items, and an additional minimization/denial scale consisting of 3 items. Items are rated on a 5-point Likert-Scale.

The Cognitive Therapy Scale Revised for Psychosis (CTS-R-P) is used as an adapted version to assess video or audio recordings of the group intervention and the preparatory session to evaluate adherence to cognitive therapy principles and the overall competence of therapists delivering the intervention. A random selection of 25% of all recordings are assessed.

Recordings of the group sessions are rated using the MBCT-AS in order to to assess how closely therapists adhere to the core principles and procedures of Mindfulness-Based Cognitive Therapy. A random selection of 25% of all recordings are assessed.

Diagnoses are confirmed using the structured interview SCID-5-RV. The SCID is an interview designed to systematically assess DSM-5 mental disorders for research purposes.

Socio-demographic data will be collected by raters at baseline to describe the study population. Core variables include age, gender, education, migration background, residential status and employment status. Clinical variables include the number of previous hospitalisations and outpatient treatments, medication and duration of illness. Medication, hospitalisations and additional treatments will be assessed additionally post-intervention and at 6-months follow-up.

Any withdrawal, and the reason for withdrawal will be documented. Reasons for withdrawal may include: 1) withdrawal of consent by participant defined as drop-out (without the need to provide justification), or 2) incorrect inclusion (e.g., subsequent determination of ineligibility).