Evolutionary Systems Therapy for Schizotypy (ESTS-RCT)

A Confirmatory Randomized Controlled Trial Comparing Evolutionary Systems Therapy for Schizotypal Personality Disorder With Cognitive Behavioral Therapy

This study aims at replicating existing preliminary evidence about the effectiveness of Evolutionary Systems Therapy for Schizotypy (ESTS). The present randomized controlled trial (RCT) will compare ESTS with Cognitive Behavioral Therapy (CBT) in treating Schizotypal Personality Disorder (SPD). The main questions our RCT aims to answer are: Is ESTS more effective than CBT in treating SPD? Is ESTS more feasible than CBT in treating SPD? 38 patients diagnosed with SPD will be recruited and randomly allocated to either the experimental group (i.e. ESTS) or the control group (CBT). Primary outcome will be reduction in general symptomatology, whereas secondary outcomes will be changes in target mechanisms (self-criticism and metacognition) and remission from diagnosis.

A previous study suggested how ESTS (experimental group; EG) may be not inferior in respect to a combine treatment comprising of CBT and psychopharmacological treatment (control group; CG). Despite the encouraging results, it has been suggested that the presence in the CG of a mandatory pharmacological treatment would have represented a bias. Indeed, a few partecipants refused pharmacological treatment. Thus, the investigators outlined an RCT aimed at comparing the two interventions (ESTS and CBT) without any mandatory pharmacological treatment. Moreover, the investigators consider the need for a pharmacological treatment during the study as an exclusion criterion. The investigators expect to extend our knowledge about the feasbility and effectiveness of ESTS for those diagnosed with SPD:

Participants are randomly assignedon a 1:1 ratio to one of two groups in parallel for the duration of the study. Each participant will access a talk therapy lasting 6 months (24 weekly sessions).

An experienced first clinician will make the initial assessment without knowing the assignment to the two groups. Similarly, a second expert clinician will evaluate the participants at the end of th.e intervention without knowing the assignment to the two groups. The data will then be anonymized and a statistician will analyze them without knowing which group corresponds to which treatment

Cognitive Behavioral Therapy for Personality Disorder as manualized by Beck, Davis, Freeman and Beck in their book (2016) will be delivered to partecipants in the active control group.

Evolutionary Systems Therapy for Schizotypy as manualized by Cheli and colleagues in their trial (2023) will be delivered to partecipants in the experimental group.

A novel therapy for schizotypal traits integrating evolutionary psychopathology, compassion focused therapy, and metacognitively oriented psychotherapy.

Change in total score of Metacognition Assessment Scale - Abbreviated (MAS-A) between two measurements

2 measurements: one at baseline assessment (once the intervention starts); one at final assessment (6 months after, that is after weekly scheduled 24 sessions)

Change in the Hated-self scale of The Forms of Self-Criticizing/attacking and Self-reassuring Scale (FSCRS) between two measurements

2 measurements: one at baseline assessment (once the intervention starts); one at final assessment (6 months after, that is after weekly scheduled 24 sessions)

Change in Socially prescribed perfectionism scale of Multidimensional Perfectionism Scale (MPS) between two measurements

2 measurements: one at baseline assessment (once the intervention starts); one at final assessment (6 months after, that is after weekly scheduled 24 sessions)

2 measurements: one at baseline assessment (once the intervention starts); one at final assessment (6 months after, that is after weekly scheduled 24 sessions)

2 measurements: one at baseline assessment (once the intervention starts); one at final assessment (6 months after, that is after weekly scheduled 24 sessions)

Change in Diagnosis of Schizotypal Personality Disorders trough Structured Clinical Interview for the DSM-5 Alternative Model for Personality Disorders (SCID-5-AMPD) Module III between two measurements

2 measurements: one at baseline assessment (once the intervention starts); one at final assessment (6 months after, that is after weekly scheduled 24 sessions)

Inclusion Criteria: Diagnosis of Schizotypal Personality Disorder at SCID-5-AMPD Module III Age 18 or older Being capable of reading and signing the inform consent form in Italian Being capable of attending a talk therapy in Italian Exclusion Criteria: Being diagnosed with schizophrenia spectrum disorders or other psychosis disorder Being diagnosed with neurodevelopmental or neurological disorders Being diagnosed with bipolar disorder Being under any psychological or pharmacological treatment