Background: Strengthening the Healthy Adult schema mode is the ultimate goal in Schema Therapy, working as an assumed mechanism of long-term change through improved positive mental health. Evidence-based interventions to directly strengthen this Healthy Adult mode are sparse.

Objective: To study the feasibility, acceptability and effectiveness of the treatment protocol 'Schema Therapy and the Healthy Adult' (ST-HA) during the final stage of schema therapy in adult outpatients with personality- or chronic psychopathology. Method: In this study a single case experimental design (n = 8) with multiple measures will be used, to determine the effects of the ST-HA protocol on self-compassion, well-being, positive affect and Healthy Adult functioning. For each participant a no-treatment randomized baseline period (2-5 weeks) will be compared with treatment (ST-HA, 10 weekly sessions) and post-treatment follow-up (at 1- and 3-months). Assessments include brief diaries regarding self-compassion and Healthy Adult functioning (daily from baseline to end of intervention, and 7-days at 1- and 3-months follow-up) and standardized questionnaires for measuring weekly changes in self-compassion, well-being and adaptive schema modes. During phase changes additional measures of trait self-compassion, positive affect, adaptive schema modes and symptomatic distress will be administered.

Schema therapy (ST; Young, 1990, Young et al., 2003) is an effective treatment for personality disorders and other chronic psychopathology, leading to significant improvement in functioning in most patients. The model of psychopathology that underlies ST is based on the assumption that when core emotional needs - especially those related to attachment stability - are insufficiently met in childhood, there is an increased chance that long-standing patterns of maladaptive thinking, feeling, behaving and coping (called schemas) will develop (i.e. Hawke & Provencher, 2011; Flink et al., 2019; Lockwood & Peris, 2012). When schemas are activated, the individual switches into a specific emotional-cognitive-behavioral state, called schema mode.

Schema therapy formulated in mode terms aims to build a Healthy Adult mode in patients by correcting dysfunctional self-representations which originate from unmet childhood needs (child modes), thereby replacing internalized critic modes with adaptive coping behavior (e.g. Arntz & Jacob, 2012; Claassen & Pol, 2013, 2014; Lobbestael et al., 2007; Young et al., 2003). This healthy, adultlike part of the self helps patients to meet their emotional needs and seems related to a longer-term view of emotional well-being (Roediger, Stevens, & Brockman, 2018). Recent studies demonstrate that building the Healthy Adult mode is crucial for long-term outcomes in patients with schema-driven perception and behavior, working as a mechanism of change through improved positive emotion regulation strategies to cope with (childhood) adversity (Louis et al., 2018; Westerhof & Wolterink, 2018; Yakin et al., 2020). A more explicit focus on healthy emotional functioning and regulation within ST seems therefore important. One useful emotional-approach coping strategy associated with healthy adult functioning is self-compassion (Trompetter et al., 2016; Yakin et al., 2019). Self-compassion is defined as being kind toward oneself (Neff, 2003b) and being able to use self-reassurance and soothing when presented with negative affect or adversities (Gilbert, 2010; Gilbert et al., 2017; Kirschner et al. 2019). It is facilitated by early experiences of care and warmth from an attachment figure, which contributed to a sense of safeness in which individuals develop a soothing-affective system (Brophy et al., 2020; Gilbert, 2014; Gilbert & Proctor, 2006; Mackintosh et al., 2018). This system exerts its protective function by stimulating physiological processes associated with stress reduction and positive affiliation affects (i.e. feeling loved, safe and securely attached) (Depue & Morrone-Strupinsky, 2005; Engen & Singer, 2015; Porges, 2007). Promoting the soothing-affective system subsequently helps reducing threat-related negative emotional states and excessive drive-related arousal (i.e. activation of dysfunctional schema modes) by increasing compassionate self-reassuring abilities, which are characterized by a caring, warm, and accepting attitude toward the self (Gilbert, 2010; Petrocchi et al., 2019; Thimm, 2017). Self-compassion therefore increases positive self, while reducing negative self (Mackintosch et al., 2018; Kirschner et al. 2019) via addressing dysfunctional schema modes. That is, the healthy side of patients is aware of self-undermining messages, can challenge them, hereby reducing their impact by practicing self-compassion with focus on attunement to emotional needs. Self-compassion and the ability to cultivate positive emotions in ourselves can thus be viewed as strategy to 'broaden- and build' healthy adult behavior (Fredrickson, 2001). Positive emotions allow us to discard habitual modes and instead look for flexible, new ways of thinking and acting (Fredrickson, 2003, 2004; Fredrickson et al., 2008). This broadened mindset can accumulate and compound to build biological (e.g. cardiac vagal tone) as well as cognitive (e.g. mindfulness), social (e.g. positive relations) and psychological (e.g. life-purpose) resources (Cloninger, 2006; Cloninger & Zohar, 2011). Experiencing positive emotions subsequently increases functional coping in a needs-based, value-driven, flexible way, serving as 'compass' for healthy adult behavior over lifetime (Bahner, 2016; Deci & Ryan, 2000; Plumb et al., 2009; Schreurs & Westerhof, 2013).

Against this background, interventions focusing on the integration of schema therapy and compassion based therapy seems promising. To our best knowledge the protocol 'Schematherapy and the Healthy Adult' (ST-HA, Broersen & Claassen, 2019) is the first direct intervention meant to strengthen patients' healthy adult functioning by developing compassion and care for well-being in the face of (childhood) adversity. The current study explores the effectiveness, acceptability and feasibility of the ST-HA protocol in adult outpatients with personality- or chronic psychopathology during final stage ST, in which there is a focus on positive mental health, resilience and preparing therapy termination. It is hypothesized that administering the ST-HA protocol: (1) will increase self-compassion, well-being, positive affect and adaptive schema modes over the intervention and follow-up period, measured by daily diary data and standardized measurements; (2) will be accompanied by self-reported symptom-reduction over the intervention and follow-up period; and (3) will be acceptable and feasible in adult outpatients.

Inclusion Criteria:

• age of 18 to 65 year
• a diagnosis of personality disorder and/or (comorbid) persistent mood-/somatic symptom disorder according to DSM-5 at the start of regular group or individual ST;
• following final stage individual or group ST (as indicated by the patients' certified Schema Therapist). If ST is terminated, this must be within four months before starting with current ST-HA study;
• suboptimal positive mental health as indicated by low to moderate levels of well-being, determined by the Mental Health Continuum
• Short Form (MHC-SF; Keyes, 2002; Lamers et al., 2011) or below average to low scores on the Positive Affect scale of the Positive And Negative Affect Schedule (PANAS; Watson et al., 1988);
• self-reported motivation for a 10-session psychological intervention focusing on positive mental health;
• have access to a computer or tablet with a good Internet connection;
• possess an e-mail address;
• have sufficient proficiency of the Dutch language (reading and writing);
• provided informed consent.

Exclusion Criteria:

• severe psychiatric disorders: acute suicidal risk, a psychotic and/or bipolar disorder, schizophrenia, delirium, dementia of severe cognitive impairment;
• ongoing other ST/psychological treatment during the baseline and treatment phase;
• former treatment based on the ST-HA protocol.

Jan. 2022 (6 months)