Psychotherapy for Self-Disorders in Schizophrenia Spectrum Disorder

Acceptance of study participation. Defined as the proportion of eligible participants who provide written informed consent and are subsequently randomized. This outcome assesses the feasibility of recruitment procedures and the acceptability of trial participation among the target population. Feasibility will be considered acceptable if at least 50% of eligible patients are enrolled and randomized.

Adherence to the SELF-7 psychotherapeutic intervention. Defined as the proportion of participants allocated to SELF-7 who complete at least 10 psychotherapy sessions. This outcome assesses feasibility of intervention delivery and participant engagement with treatment. Feasibility will be considered acceptable if at least 70% of intervention participants complete a minimum of 10 sessions.

Patient satisfaction with the SELF-7 intervention assessed using the Client Satisfaction Questionnaire-8 (CSQ-8) at end of therapy (week 16). The CSQ-8 is an 8-item self-report measure of perceived quality, usefulness, and acceptability of care. Higher scores indicate greater satisfaction with treatment. Feasibility will be considered acceptable if at least 70% of participants achieve a mean CSQ-8 score greater than 3.5.

Participant evaluation of the SELF-7 intervention assessed using the purpose-developed patient version of SELF-7 Treatment Feedback Scale (STFS). The patient version of STFS is a 4-item participant-rated measure assessing perceived therapeutic understanding, relevance of therapeutic content, usefulness of the therapeutic approach, and overall benefit of SELF-7 for understanding and managing self-disorders. Items are rated on an 11-point scale ranging from 0 ("not at all") to 10 ("to a very high degree"). Mean scores range from 0 to 10, with higher scores indicating more positive evaluations and greater acceptability of the intervention. Feasibility will be considered acceptable if at least 70% of participants provide overall positive feedback.

Therapist evaluation of the SELF-7 intervention assessed using the purpose-developed terapist version of SELF-7 Treatment Feedback Scale (STFS). The terapist version of STFS is a 4-item therapist-rated measure assessing therapeutic alliance and collaboration, relevance of therapy content, appropriateness of the therapeutic approach, and the overall contribution of SELF-7 to the patient's understanding and management of self-disorders. Items are rated on an 11-point scale ranging from 0 ("not at all") to 10 ("to a very high degree"). Mean scores range from 0 to 10, with higher scores indicating more positive evaluations and greater acceptability of the intervention. Feasibility will be considered acceptable if at least 70% of therapists provide overall positive feedback.

Therapy-related adverse effects will be assessed at end of therapy using the Negative Effects Questionnaire (NEQ-20), a 20-item self-report measure designed to assess unwanted and adverse effects associated with psychological treatment. The NEQ-20 will be used to evaluate the safety and tolerability of the SELF-7 intervention, alongside monitoring of serious therapy-related adverse events. Items are rated on a 5-point scale, and mean scores range from 0 to 4, with higher scores indicating more frequent and/or severe negative effects of treatment. A mean score of 0 indicates no reported negative effects, whereas a mean score of 4 indicates the highest level of reported negative effects. The adverse effects criterion is met if no more than one serious therapy-related adverse event (as defined in the protocol) occurs during the intervention period (week 0 - week 16) and if fewer than 10% of participants have a mean NEQ-20 score greater than 2 measured at end of therapy (week 16).

Psychological Outcome Profiles (PSYCHLOPS), an individualized idiographic patient-reported outcome measure (I-PROM) that measures psychological distress, and will serve as the primary exploratory outcome. PSYCHLOPS includes four items covering three domains: (1) Problems; (2) Function; and (3) Well-being. A six-point rating scale is used to score the intensity and duration of psychological distress. PSYCHLOPS is adapted to assess psychological distress related to self-disorders, as participants follow a structured procedure that guides them in identifying and rating their main self-defined psychological problems and associated distress related to self-disorder phenomena. Higher scores indicate greater psychological distress related to self-disorders.

The RPI is a self-report measure to assess seven dimensions of readiness for psychotherapy: level of distress, desire for change, willingness to work in therapy, recognition of problems as psychological, willingness to discuss personal matters, willingness to endure discomfort in therapy, and responsibility for change. 42 items; 5-point Likert scale. 7 subscales; total score and subscale scores are analyzed; higher scores indicate greater readiness.

The Brief INSPIRE-O is a patient-reported outcome measure assessing personal recovery across the domains of connectedness, hope, identity, meaning, and empowerment (CHIME). The instrument consists of 10 items covering five domains, rated on a 5-point Likert scale. Total scores range from 10 to 50. Higher scores indicate greater perceived personal recovery.

The WHO Well-Being Index (WHO-5) is a self-report measure of current subjective psychological well-being. The instrument consists of 5 items rated on a 6-point Likert scale. Raw scores range from 0 to 25 and are transformed to a scale ranging from 0 to 100. Higher scores indicate better well-being.

The Perceived Stress Scale (PSS-10) is a self-report questionnaire assessing the degree to which individuals perceive their lives as stressful, unpredictable, and overloaded during the past month. The instrument consists of 10 items rated on a 5-point Likert scale. Total scores range from 0 to 40. Higher scores indicate greater perceived stress.

The Suicidal Ideation Attributes Scale (SIDAS) is a self-report measure assessing the severity and impact of suicidal ideation, including frequency, controllability, distress, and interference with daily functioning. The instrument consists of 5 items rated on 11-point scales. Total scores range from 0 to 50. Higher scores indicate greater suicidal ideation severity.

The Personal and Social Performance Scale (PSP) is a clinician-rated measure assessing functioning across four domains: socially useful activities, personal and social relationships, self-care, and disturbing/aggressive behaviors. Total scores range from 1 to 100. Higher scores indicate better personal and social functioning.

The Scale for the Assessment of Positive Symptoms (SAPS) is a clinician-rated instrument assessing the severity of positive psychotic symptoms, including hallucinations, delusions, bizarre behavior, and positive formal thought disorder. The instrument consists of 34 items across four global domains and includes both item-level and global domain ratings. Items are rated on a 6-point scale (0-5). Higher scores indicate greater positive symptom severity, with a score of 0 reflecting the absence of positive symptoms and higher scores reflecting increasing symptom severity.

The Brief Negative Symptom Scale (BNSS) is a clinician-rated scale assessing core negative symptom domains, including anhedonia, asociality, avolition, blunted affect, and alogia. The instrument consists of 13 items across five domains. Each item is rated on a 7-point scale (0-6), yielding a total score ranging from 0 to 78, with higher scores indicating greater negative symptom severity. A score of 0 reflects the absence of negative symptoms, whereas higher scores reflect increasing severity of negative symptoms. Total and domain scores will be analyzed.

Insight assessed using Item G12 from the Positive and Negative Syndrome Scale (PANSS). G12 is a clinician-rated item evaluating awareness and understanding of having a mental illness, recognition of symptoms as pathological, and appreciation of the need for treatment. Scores range from 1 to 7. Higher scores indicate poorer insight and greater lack of judgment.

The Examination of Anomalous Self-Experience (EASE) is a semi-structured interview comprising 57 main items distributed across five domains: Cognition and stream of consciousness, Self-awareness and presence, Bodily experiences, Demarcation/transitivism, and Existential reorientation/solipsism. Items are rated dichotomously as present or absent. Scores are summed into an EASE total score, where 1 point corresponds to the presence of 1 self-disorder item. Higher scores indicate greater levels of self-disorders.