Integrating Positive Schemas in Schema Therapy for Cluster C Personality Disorders in Older Adults: A Multiple Baseline Study

ABSTRACT

Schema therapy (ST) is an effective psychotherapy for personality disorders in (older) adults. There is an increasing awareness of the imbalance in the ST community because of the emphasis on negative schemas versus attention to positive schemas. This study aimed to evaluate the effectiveness of an adapted ST approach that integrates positive schemas. Using a multiple baseline design, the study assessed 10 older adults (aged > 60) with Cluster C personality disorders through 1 year of weekly individual ST sessions, followed by a 6‐month follow‐up. Baseline consisted of 4–8 weeks without intervention. Primary outcomes were credibility of positive and negative core beliefs; secondary measures examined symptomatic distress, schema modes, early maladaptive and positive schemas. Results showed mixed individual outcomes. Positive core beliefs significantly improved in 38% of participants during treatment and 50% at follow‐up, whereas negative core beliefs decreased significantly for 25% of participants during treatment and 67% at follow‐up. At the group level, significant increases with very large effect sizes were observed in positive core beliefs in baseline versus follow‐up and reductions in negative beliefs in baseline versus treatment and versus follow‐up. Secondary outcomes revealed significant reductions in symptomatic distress and PD criteria, alongside increased positive schemas. No significant changes were found for schema modes or maladaptive schemas. This first study underscores the potential of integrating positive schemas into ST for older adults, suggesting preliminary efficacy. Further research is essential to generalize findings across different age groups and diagnoses and to identify which aspects of positive schemas enhance therapy outcomes.

Summary

• The first evidence for integrating positive schemas in ST is promising and may lead to better treatment outcomes.

• Preliminary findings support a balanced focus on both maladaptive and positive schemas in schema therapy to optimize therapeutic outcomes, especially in older populations.

• More research is required to explore additional psychotherapeutic techniques for building positive schemas.

1. Introduction

Schema therapy (ST) was developed in the 1990s by Young et al. (2003) from dissatisfaction with the outcomes of cognitive therapy for people with personality disorders (PDs). Young added components from attachment, psychodynamic and experiential theory and therapy. ST is an evidence‐based psychotherapy for the treatment of PDs. The ST model holds that unmet needs during childhood and adolescence can give rise to the development of early maladaptive schemas (EMS) and the formation of maladaptive schema coping modes. EMS, or negative schemas, are regarded as core elements of PDs (Young et al. 2003). EMS are broad, pervasive themes comprising specific patterns of self‐defeating emotions, cognitions and bodily sensations regarding oneself and one's relationship with others. These patterns are established in childhood and repeated throughout life (Young et al. 2003). A schema mode is defined as a momentary, dynamic emotional–cognitive state that encompasses the activation of one or more EMS, coping responses and associated emotional experiences. Modes represent shifting aspects of the self that dominate an individual's thoughts, feelings and behaviours in response to specific triggers. The objective of ST is to decrease the impact of EMS and to replace negative coping responses and schema modes with more healthy alternatives, thereby enabling patients to succeed in getting their core emotional needs met (Rafaeli et al. 2010).

Due to the initial success of ST with borderline PDs, modifications are regularly made to schema therapy as described by Young et al. (2003) to make it more appropriate for specific populations (Jacob and Arntz 2013; van Dijk et al. 2023). For instance, it has been extended to other PDs (Arntz 2012; Bamelis et al. 2014), forensic populations (Bernstein et al. 2012, 2019), eating disorders (Joshua et al. 2023), chronic depression (Renner et al. 2016), anxiety disorders (Hawke and Provencher 2011) and age (Roelofs et al. 2016; Videler et al. 2018) and is adapted for group therapy (Arntz et al. 2022; Farrell et al. 2009; Tracy et al. 2024).

In older adults, ST is a well‐established evidence‐based, integrative psychotherapeutic treatment for PDs. The feasibility and efficacy of ST in treating PDs in older adults have been demonstrated in several studies (Khasho et al. 2023; van Dijk et al. 2023; Veenstra‐Spruit et al. 2024; Videler et al. 2014, 2018). However, the observed effects were found to be smaller than those reported in studies conducted with a younger adult population (Arntz et al. 2022; Renner et al. 2013; Van Vreeswijk et al. 2012; Videler et al. 2020, 2021). This discrepancy may be attributed to the fact that ST was originally designed for younger adults and requires modifications to align more effectively with the psychotherapeutic needs of older adults with PDs.

Based on the experiences of a case study, hypotheses were generated on how to adapt ST for older adults (Videler et al. 2017). Suggestions included (i) to make use of a compact case conceptualization that clearly describes both schemas and modes; (ii) using the spontaneous language of the patient instead of the ST terminology, both in the case conceptualization and in therapy; (iii) modifications to the imagery re‐scripting technique because of the patient's relatively stronger healthy adult mode and life experience; (iv) simplifying the chair technique by not using more than two chairs; (v) addressing older adults' ‘wisdom’ by helping them to see their problems in a life span perspective and make use of their experience to have coped with problems successfully earlier in life; (vi) addressing negative core beliefs about ageing, psychiatry and psychotherapy, which can possibly contribute to negative schemas; and (vii) lastly, the suggestion to incorporate positive schemas in ST for older adults. It has been proposed that older adults may particularly benefit from integrating positive schemas in ST (Videler et al. 2020). Often, older people with PDs have functioned better earlier in life, as their positive schemas were confirmed by their social roles. With the evaporation of these roles, this confirmation also dissolves, which can lead to activation of negative schemas (Videler et al. 2014, 2020).

The focus on the positive aspects of psychotherapy is a phenomenon that can be observed beyond the scope of ST. This phenomenon is evident in a variety of contexts, including positive psychology (Carr et al. 2021; Chakhssi et al. 2018; Lee Duckworth et al. 2005; Seligman and Csikszentmihalyi 2000) and solution‐focused therapy (De Shazer et al. 2021). Additionally, it is discernible within the principles of metacognitive interpersonal therapy, as demonstrated by the emphasis on positive self‐aspects (Dimaggio et al. 2020). Moreover, within the ST framework, a consistent emphasis has been placed on positive aspects, through the Healthy Adult and Happy Child modes (Young et al. 2003). Recently, however, there has also been a focus on positive schemas within ST. In their 2012 paper, Lockwood and Perris put forth the first conceptualization of a positive schema or an early adaptive schema (EAS), which they defined as the positive counterpart of a negative schema, or EMS. They posited that EAS, as EMS, are also specific patterns comprising emotions, cognitions, bodily sensations and neurobiological reactions pertaining to the self and others. These schemas are postulated to emerge when individuals mature and develop in environments where their core emotional needs are adequately fulfilled by primary caregivers (Taylor and Arntz 2016; Young et al. 2003). People can experience EAS and EMS simultaneously. The presence and strength of an EMS may serve as negative predictors of the strength of the corresponding EAS. However, a reduction in the strength of an EMS does not necessarily result in a corresponding increase in the strength of an EAS. Each EAS represents more than the polar opposite of its corresponding EMS. This conceptualization of EMS and EAS as distinct dimensions was supported by several empirical studies of Louis et al. (2018, 2020, 2023, 2024). The Young Positive Schema Questionnaire (YPSQ) was developed for the purpose of measuring EAS. Complementary to the original 18 EMS, Louis et al. identified a 56‐item, 14‐factor EAS solution, divided into four domains, which was supported by a multi‐group confirmatory factor analysis (see Table 1 for the 14 EAS) (Louis et al. 2018, 2024). As the EAS showed incremental validity over and above the EMS, EAS and EMS can be conceived of as separate constructs, and not just opposite ends of continua (e.g., mistrust vs. trust; failure vs. success) (Louis et al. 2018, 2023, 2024; Ouwens et al. 2025). People are inclined to hold multiple contradictory beliefs about themselves and the world (Wood and Johnson 2016), and their behaviour depends on which particular schema is activated at the time.

TABLE 1.

Early adaptive schemas (Louis et al. 2018, 2024).

Positive domain	Positive schema (EAS)
Connection and acceptance	Emotional fulfilment
	Social belonging
	Emotional openness and spontaneity
	Healthy self‐interest/self‐care
Healthy autonomy and performance	Healthy self‐reliance/competence
	Healthy boundaries/developed self
	Stable attachment
Reasonable limits	Healthy self‐control/self‐discipline
	Success
Healthy standards and reciprocity	Realistic expectations
	Self‐directedness
	Basic health and safety/optimism
	Empathic consideration
	Self‐compassion

There are also other authors who have written about the integration of positive schemas and modes in ST (e.g., Arntz and Jacob 2017; Behary et al. 2023; Lockwood and Samson 2020; Taylor and Arntz 2016; Yin et al. 2022). For an overview, see van Donzel et al. (unpublished manuscript). Adapting ST as usual is therefore part of a long tradition of research on optimization for specific groups.

The aim of this study was to examine the effectiveness of adapted ST for older adults as a treatment for Cluster C PDs in individuals aged 60 and above. Specifically, we examined whether older patients with cluster C PDs benefit from adapted ST, which incorporates and operationalizes all the aforementioned adaptations proposed by Videler et al. (2017). We added interventions specifically aimed at reactivating EAS: a modified case conceptualization incorporating positive schemas; a positive timeline describing periods when a person was functioning well/better, including the positive schemas that were active during this period, positive imaginations to these positive schemas; and finally, interventions to (re)activate positive schemas. The primary objective of the study was to examine the effect of adapted ST on the strength of both positive and negative core beliefs, which are closely related to the EMS and EAS of the participants—the core elements of their PD pathology (Young et al. 2003). The hypothesis was that the strength of negative core beliefs would be reduced and the strength of positive core beliefs would be increased in the treatment and follow‐up phase in comparison to the baseline phase. Additionally, it was hypothesized that, as a result of adapted ST, dysfunctional schemas and modes would decrease and positive schemas and modes would increase in the follow‐up phase compared to the baseline phase. Based on earlier research (Videler et al. 2018), it was expected that patients would no longer meet the criteria of a PD after adapted ST treatment.

2. Methods

2.1. Design of the Study, Procedure, Instruments and Measurements

An elaborate description of the study design, the selection procedure and measurement instruments can be found in the trial paper previously published about this (Van Donzel et al. 2021). A summary is provided below.

2.1.1. Design of the Study

A multiple‐baseline case series design was employed (Kazdin 2011; Kazdin and Tuma 1982). The study was conducted in three phases: baseline, treatment and follow‐up. In the baseline, participants were randomly assigned to a 4‐ to 8‐week baseline period without ST interventions. The second phase was a 1‐year treatment phase, consisting of a ST for PDs as described by Young et al. (2003) targeting both EMS and schema modes, including healthy modes. We added the aforementioned adaptations for older adults, as suggested by Videler et al. (2017). The third and final phase consisted of a 6‐month follow‐up period, with monthly booster sessions with the aim of consolidating gains and addressing any impediments encountered. In all three phases of the study, the primary outcome measure was administered on a weekly basis, whereas the secondary outcome measures were collected once every 6 months. A graphical representation of the study design is provided in Figure 1.

FIGURE 1.

CONSORT flowchart. †Participant 1 withdrew due to a prolonged cessation of therapy resulting from the impact of COVD‐19. ‡Participant 4 withdrew due to her inability to comply with the conditions outlined in the informed consent. Participant 5 withdrew due to difficulties in her working relationship with the therapist.

2.1.2. Participants

The participants were patients from the departments of geriatric psychiatry at GGZ Oost Brabant, GGZ Breburg and GGZ Mondriaan, and a private practice was added. Inclusion and exclusion criteria are (1) age of 60 years and older, (2) willingness to participate in the study and (3) a primary diagnosis of an avoidant, dependent or obsessive–compulsive PD or PD otherwise specified with Cluster C traits, also known as Cluster C PD. More details are described in Van Donzel et al. (2021).

2.1.3. Instruments

We used the Gerontological Personality Disorders Scale (GPS; Van Alphen et al. 2006) and the Mini‐International Neuropsychiatric Interview (MINI) (Sheehan et al. 1998) (Dutch version; Overbeek et al. 1999) for the purpose of diagnosis. The psychometric properties of these tests can be found in the trial paper of this study (Van Donzel et al. 2021).

2.1.4. Measurements

2.1.4.1. Primary Outcome

The primary outcome measure was the assessment of the credibility of the core beliefs. Due to ethical considerations, it was not feasible to measure EAS and EMS on a weekly basis for a period of 1.5 years. Core beliefs were therefore selected: a significant representation of EAS and EMS that was viewed by the participant as central to their PD problems that is sensitive to change and can be taken frequently (David and Freeman 2015). At the start of the baseline phase, participants were instructed to describe two to three core beliefs based on the highest scoring EMS as measured by YSQ‐S3 and two to three core beliefs based on the highest scoring EAS as measured by YPSQ in brief statements. This was done using a semi‐structured procedure, which involved utilizing the downward arrow technique to evoke these core beliefs (Khasho et al. 2023; van Houten et al. 2024; Videler et al. 2018). The credibility of these statements was evaluated weekly in all three phases on a visual analogue scale (VAS) comprising a 100‐point scale, with scores ranging from 0 to 100%. The therapist was not present when participants filled in the VAS to assure integrity. Filled‐in forms were given to the therapist in a closed envelope and passed on to the research team.

2.1.4.2. Secondary Outcomes

As secondary outcomes, we used the Structured Clinical Interview for DSM‐5 for Personality Disorders (SCID‐5‐PD; First et al. 2016); Dutch version of the Brief Symptom Inventory (BSI; De Beurs 2011), translated from the original scale (Derogatis 1975); the Young Schema Questionnaire L2 (YSQ; Young and Brown 1994), the Dutch translation (Sterk and Rijkeboer 1997); the Young Positive Schema Questionnaire (YPSQ; Louis et al. 2018) in Dutch (Ouwens et al. 2025); and the Schema Mode Inventory (SMI) (Young et al. 2007), the Dutch translation (Lobbestael et al. 2010). The psychometric information of these tests can be found in the trial paper of this study (Van Donzel et al. 2021).

The SCID‐5‐PD was administered at the outset of the study and at the end of the treatment phase, following Videler et al. (2018). Patients completed the YSQ, SMI, BSI and YPSQ at four time points: (i) before the start of the baseline phase, (ii) 6 months after the start of ST, (iii) after termination of therapy and (iv) after a 6‐month follow‐up. Secondary outcome measures were administered within the mental health centre where participants received their treatment. For the CONSORT flowchart, see Figure 1.

2.1.5. Procedure

Potential participants were approached by the researcher (L.v.D.) and were fully informed about the study. They all gave written consent to participate. Treatment was offered by six female therapists, with a mean 16.67 years of experience as psychologists and a mean 8.17 years of experience as schema therapists. Peer supervision was provided every 3 months, chaired by an International Society of Schema Therapy certified ST supervisor to ensure treatment adherence and therapy fidelity and to discuss issues that therapists encountered.

2.2. Data Analysis

2.2.1. Primary Outcome Measures

For the analysis of the weekly measured core beliefs, both visual inspection analysis and statistical testing were performed on nine participants, including two drop‐outs. In order to evaluate the effect of the treatment on the core beliefs, the VAS scores on the three positive core beliefs and the three negative core beliefs were averaged, resulting in two new variables representing the means. The pattern of positive and negative core beliefs was evaluated over time, inspecting the variation in scores, the mean trend, the effect of the treatment and the overlap in scores using the Tau‐U measure. The Tau‐U measure (Parker et al. 2011) expresses the non‐overlap of two phases and combines phases (similar to the Mann–Whitney U test) and the trend within and between phases (similar to Kendall's tau). Tau‐U is a correlation, which varies between −1 and 1, with negative values indicating a negative trend, with no overlap in scores, and positive values indicating a positive trend. Tau‐U is chi‐squared distributed, and therefore, a significance level can be derived.

The difference in means of the baseline and the treatment phase and baseline and follow‐up phase was statistically evaluated using non‐parametric tests. Note that, as the asymptotic assumptions of parametric tests are often violated because the number of participants is small, non‐parametric tests are more appropriate. The permutation distance test (PDT) (VroegindeWeij et al. 2023) was used to compare the means of the baseline and treatment and the baseline and the follow‐up for each individual. The PDT corrects for autocorrelation. VroegindeWeij et al. (2023) showed that PDT has more power than the often used permutation test of Koehler and Levin (1998). Finally, Cohen's d was calculated as a measure of effect size.

In order to statistically evaluate the effect at group level, a p value for the group was calculated. To calculate this p value, the property of p values was used that, according to the null hypothesis, they are uniformly distributed between 0 and 1. Given this property, the probability of a sum of p values can be computed, given the null hypothesis that states that the individual p values that add up to the sum are uniformly distributed (Onghena 2005).

2.2.2. Secondary Outcome Measures

To analyse the level of symptomatology (BSI), EMS (YSQ), EAS (YPSQ) and schema modes (SMI), a paired samples t‐test was employed to compare baseline with follow‐up for the seven participants that completed the study. Due to issues with normality, it was not possible to apply a repeated measures design to these variables using baseline through follow‐up. A paired samples t‐test can be applied to a small sample size when the within‐pair correlation is high (r ≤ 0.7) and the effect size is large (Cohen's d ≤ 0.8) (De Winter 2019). In instances where the prerequisites for a paired samples t‐test were not satisfied, a Wilcoxon signed‐rank test was employed.

In order to determine whether the change score on the secondary outcome measures over time is statistically significant, a reliable change index (RCI) was calculated pre and post follow‐up. Finally, it was determined for each participant whether they still met the criteria for a PD based on the SCID‐5‐P.

3. Results

3.1. Treatment Characteristics

Participants were 10 older native Dutch‐speaking individuals with an avoidant, obsessive–compulsive and/or a dependent PD. Age ranged from 62 to 71 years (mean age = 65.3 years). See Table 2 for an overview of the demographics. Ten participants were enrolled in the study. Of these, three (33%) dropped out for various reasons, which are discussed below. Drop‐out in psychotherapy for people with PD is common; a recent systematic review (De Salve et al. 2025) shows that it occurs between 22.9% (Alesiani et al. 2014) and 47% (Herzog et al. 2020) in people with PD.

TABLE 2.

Demographic data of participants (n = 10).

PN	Gender	Age	Classification	BL	Treatment
1	F	65	AV	5	DO a
2	F	62	AV	4	CO
3	M	66	AV	4	CO
4	F	65	DE	7	DO b
5	F	62	OC	6	DO c
6	F	68	AV	8	CO
7	M	68	OC, DE	5	CO
8	F	63	DE	8	CO
9	M	71	AV	7	CO
10	M	63	OC	6	CO

Abbreviations: AV = avoidant personality disorder, BL = baseline period in weeks, CO = completed, DE = dependent personality disorder, DO = drop‐out, F = female, M = male, OC = obsessive–compulsive personality disorder, PN = participant.

^a After baseline.

^b After Session 17 of treatment.

^c Before follow‐up.

The study took place from February 2020 until October 2023. Directly after the start of the study, the global outbreak of the COVID‐19 pandemic occurred. Due to the regulations in the Netherlands for the management of this pandemic, the enrollment of participants was delayed. At that time, only one participant was enrolled (Participant 1, in baseline phase). Due to the prolonged cessation of therapy, Participant 1 chose to terminate her treatment.

Participant 4 stopped in consultation with her therapist because she could not comply with the conditions described in informed consent. In addition to adapted ST, she wanted to add other counselling. Participant 5 stopped voluntarily due to problems in the working relationship with the therapist.

3.2. Primary Outcome Measures: Positive and Negative Core Beliefs

For the visual inspection analysis, the pattern of the variables was evaluated for a total of nine participants. It should be noted that, due to the drop‐out of Participant 1 during the baseline phase, this participant was not included in the analyses. Participant 8 had only one observation during the baseline phase; as a consequence, no statistical tests could be performed for this participant. Participants 4 and 5 dropped out; therefore, no follow‐up data were available.

As illustrated in Tables 3, 4, 5 and Figures 2, 3, 4, 5, 6, 7, 8, 9, 10, positive core beliefs exhibited a significant increase from baseline to treatment phase in three participants (38%; 50% of the completers) and baseline to follow‐up phase in three participants (50% of the completers), with p values ranging from 0.001 to 0.035 and large to very large effect sizes in participants with significant changes (Cohen's d = 1.44–5.19). Tau‐U values were positive in five participants (63%; 83% of the completers) in baseline versus treatment phase and in six participants (100%) in baseline versus follow‐up phase, indicating non‐overlapping improvements. However, three participants (38%; 13% of completers) showed negative Tau‐U, and a significant decline in positive beliefs was observed for participant 4 (Tau‐U = −0.62). Participant 9 displayed ceiling effects in positive core beliefs, limiting measurable change. For negative core beliefs, significant reductions were observed after treatment in two participants (25%; 17% of the completers; p values between 0.005 and 0.048) and more prominently at follow‐up with four participants (67%; p values between < 0.001 and 0.026), with large effect sizes for participants with significant changes (Cohen's d = 0.72–10.37). Tau‐U values for negative beliefs were negative for seven participants (88%; 83% of the completers) for baseline versus treatment phase and for five participants (83%) in baseline versus follow‐up, indicating desirable non‐overlapping decreases. Nonetheless, one participant showed increases in negative beliefs despite subjective reports of improvement. A more detailed explanation of each of the results per participant can be found in the Supporting Information.

TABLE 3.

Non‐overlapping effect size Tau‐U for negative and positive core beliefs.

	Negative core beliefs				Positive core beliefs
Pp.	$\tau$‐U Ba versus Tr	Sig.	$\tau$‐U Ba versus FU	Sig.	$\tau$‐U Ba versus Tr	Sig.	$\tau$‐U Ba versus FU	Sig.
2	0.26	0.029	0.36	0.127	0.37	0.002	0.54	0.015
3	−0.37	0.002	−0.52	0.001	0.27	0.023	0.42	0.017
4	−0.05	0.843			−0.62	0.004
5	−0.22	0.135			−0.23	0.141
6	−0.25	0.017	−0.61	< 0.001	−0.12	0.254	0.17	0.357
7	−0.02	0.871	−0.16	0.351	0.24	0.032	0.40	0.023
9	−0.59	< 0.001	−0.71	< 0.001	0.26	0.053	0.24	0.165
10	−0.41	0.001	−0.62	< 0.001	0.20	0.105	0.51	0.004

Abbreviations: Ba = baseline, FU = follow‐up, Tr = treatment.

TABLE 4.

Results of randomization tests for mean positive core beliefs per phase per participant.

Pp.	MBaseline	MTreatment	MFU	Diff.Ba‐Tr	Sig.	Effect size	Diff.Ba‐FU	Sig.	Effect size
2	75.00	82.22	80.50	7.22	0.028	2.93	5.50	0.001	2.16
3	54.58	69.30	71.41	14.71	0.015	2.54	16.83	0.019	5.19
4	79.52	69.67		−9.86	0.948	1.15
5	80.83	79.14		−1.70	0.702	0.29
6	66.88	60.98	68.42	−5.90	0.794	0.5	1.55	0.348	0.2
7	72.00	79.28	78.29	7.28	0.035	1.44	6.29	0.174	0.46
9	95.71	99.00	98.72	3.29	0.076	1.04	3.00	0.130	0.8
10	75.00	79.57	84.13	4.57	0.126	0.74	9.13	0.020	2.23

Abbreviations: Ba = baseline, FU = follow‐up, Tr = treatment.

TABLE 5.

Results of randomization tests for mean negative core beliefs per phase per participant.

Pp.	MBaseline	MTreatment	MFU	Diff.Ba‐Tr	Sig.	Effect size	Diff.Ba‐FU	Sig.	Effect size
2	74.17	78.19	76.50	4.02	0.925	1.12	2.33	0.982	1.45
3	79.17	58.62	46.03	−20.55	0.005	2.33	−33.14	< 0.001	5.15
4	90.48	90		−0.476	0.447	0.46
5	67.78	56.75		−11.03	0.048	0.72
6	68.33	60.88	55.97	−7.46	0.073	0.86	−12.37	0.026	1.97
7	74.67	73.50	71.67	−1.17	0.424	0.16	−3.00	0.330	0.41
9	59.29	6.47	4.49	−52.82	0.066	4.16	−54.80	0.007	10.37
10	87.50	63.97	21.74	−23.53	0.060	1.6	−65.76	0.012	8.92

Abbreviations: Ba = baseline, FU = follow‐up, Tr = treatment.

FIGURE 2.

Plot of the mean negative and positive core beliefs of Participant 2.

FIGURE 3.

Plot of the mean negative and positive core beliefs of Participant 3.

FIGURE 4.

Plot of the mean negative and positive core beliefs of Participant 4.

FIGURE 5.

Plot of the mean negative and positive core beliefs of Participant 5.

FIGURE 6.

Plot of the mean negative and positive core beliefs of Participant 6.

FIGURE 7.

Plot of the mean negative and positive core beliefs of Participant 7.

FIGURE 8.

Plot of the mean negative and positive core beliefs of Participant 8.

FIGURE 9.

Plot of the mean negative and positive core beliefs of Participant 9.

FIGURE 10.

Plot of the mean negative and positive core beliefs of Participant 10.

3.2.1. Group Effects

The group effect for the positive core beliefs in the baseline versus treatment phase the p value was 0.062, indicating that the pattern of individual effects did not indicate a significant effect at the group level, but with a very large effect size (Cohen's d = 1.37). For baseline versus follow‐up comparison, the p value was 0.003, indicating that the pattern of individual effects indicates a significant effect at the group level, with a very large effect size (d = 1.87). For the negative core beliefs, in the baseline versus treatment phase, the p value was 0.007, indicating that the pattern of individual effects indicates a significant effect at the group level with a very large effect size (Cohen's d = 1.43). For baseline versus follow‐up, the p value was 0.009, indicating that the pattern of individual effects indicates a significant effect at the group level, again with a very large effect size (d = 4.76).

3.3. Secondary Outcomes

3.3.1. Symptomatic Distress

The individual scores on psychological distress of the participants, measured with the BSI, decreased. A Wilcoxon signed‐rank test showed that there was a significant reduction in symptomatic distress between baseline and follow‐up phase (z = −2.197, n = 7, p = 0.028) with a medium effect size (r = 0.314; see Table 6). As illustrated in Table 7, the RCIs for severity symptomatic distress, as measured by BSI, are presented. These RCIs are based on psychometrics from the validation in a Dutch clinical sample (De Beurs and Zitman 2005). Of the seven participants who completed both pre‐ and post‐assessments, 71% (five participants) exhibited a significant positive reliable change (RCI > 1.96) in the total scores. In the subscales, 27 (39%) subscales demonstrated a positive reliable change, whereas one subscale (1%) exhibited a significant negative reliable change.

TABLE 6.

Results of Wilcoxon signed‐rank tests.

Questionnaire	Baseline mean	Follow‐up mean	z	Sig.	r
BSI	1.355	0.580	−2.197	0.028	0.314
YPSQ	3.283	3.990	2.028	0.043	0.290

Abbreviations: BSI = Brief Symptom Inventory, Sig. = significance, YPSQ = Young Positive Schema Questionnaire.

TABLE 7.

RCI of the BSI pre‐/post‐test of the sub‐scores and the total score.

PN	som	cog	int	dep	ang	hos	fob	par	psy	Total
2	7.41 a	0.00	2.86 a	0.92	−6.14 b	1.80	0.24	4.54 a	−1.90	2.64 a
3	0.46	2.60 a	2.86 a	2.72 a	1.90	3.60 a	2.41 a	2.52 a	1.43	5.97 a
6	0.85	2.16 a	−1.14	0.44	1.87	−1.80	1.45	0.00	1.43	1.60
7	0.46	4.77 a	2.86 a	2.72 a	2.83 a	1.80	2.41 a	1.01	1.90	5.90 a
8	2.16 a	2.60 a	2.86 a	3.18 a	1.42	0.00	1.93	2.52 a	1.43	5.63 a
9	−1.77	0.00	0.00	−0.90	0.45	0.00	0.00	0.00	−0.48	−1.04
10	0.85	2.60 a	4.58 a	4.08 a	5.18 a	3.00 a	1.93	5.55 a	3.33 a	8.47 a

Abbreviations: ang = anxiety, cog = cognitive problems, dep = depression, fob = phobic anxiety, hos = hostility, int = interpersonal sensitivity, par = paranoid ideation, PN = participant number, psy = psychoticism, som = somatization.

^a Significant positive reliable change (> 2).

^b Significant negative reliable change (< −2).

3.3.2. Schema Modes

A paired samples t‐test was conducted on both the positive schema modes and the negative schema modes. The combined scores on negative schema modes (vulnerable child, angry child, raging child, impulsive child, undisciplined child, compliant surrender, detached protector, over‐compensator, bully and attack, punitive parent and demanding parent) did not decrease significantly (t = 1.852, p = 0.114). The positive schema modes (healthy adult and happy child) did not increase significantly either (t = −1.859, p = 0.112; see Table 8). The RCI of the subscales of the SMI based on the psychometrics of a Dutch‐speaking clinical and non‐clinical sample (Lobbestael et al. 2010) is presented in Table 9. Of the positive schema modes, three scores (21%) demonstrated a positive reliable change, whereas three scores (21%) exhibited a negative reliable change. In the negative schema modes, 32 scores (38%) demonstrated a positive reliable change, whereas 7 scores (8%) exhibited a negative reliable change.

TABLE 8.

Results of paired samples t‐tests.

Questionnaire	Baseline mean (SD)	Follow‐up mean (SD)	t	p	Effect size
SMI negative	2.501 (0.544)	2.161 (0.470)	1.852	0.114	0.491
SMI positive	3.412 (0.602)	3.855 (0.923)	−1.859	0.112	0.617
YSQ	2.641 (0.796)	2.167 (0.804)	1.841	0.115	0.681
SCID‐5‐PD	24.429 (8.364)	11.000 (8.083)	6.352	< 0.001	2.401

Abbreviations: SCID‐5‐P = Structured Clinical Interview for DSM‐5 Personality Disorders, SD = standard deviation, SMI negative = negative modes of the Schema Mode Inventory, SMI positive = positive modes of the Schema Mode Inventory, YSQ = Young Schema Questionnaire.

TABLE 9.

RCI of the SMI pre‐/post‐test of the sub‐scores.

PN	V	A	E	I	U	H	CS	DP	DS	SA	BA	PP	DPa	HA
2	1.35	−0.96	0	−1.21	−1.46	6.89 b	−4.96 b	−2.38 b	−0.57	0.83	0.69	−4.12 b	2.47	0.40
3	5.86 a	2.57 a	3.46 a	0.34	0.77	−3.67 a	1.79	0.43	0	2.79 a	0.33	3.09 a	3.16	−0.62
6	−0.45	−5.45 b	−1.69	−2.33 b	−1.86	−1.84	3.20 a	0.78	5.13 a	−1.95	−2.00 b	2.06 a	1.23	−1.56
7	0.90	0.64	−0.23	3.02 a	−0.70	−3.21 a	1.76	0.78	1.71	0.06	0	1.34	4.56 a	−0.62
8	16.67 a	11.23 a	3.84 a	11.28 a	7.43 a	14.69 b	9.58 a	11.42 a	7.99 a	7.25 a	7.27 a	7.90 a	11.48 a	12.75 b
9	−0.45	−0.96	0	−0.37	0	−1.38	0	0	−2.28 b	0.56	0	0	2.04 a	−1.87
10	5.41 a	1.92	0.35	4.01 a	1.63	−4.59 a	2.48 a	6.31 a	1.71	3.07 a	2.00 a	1.72	3.44 a	−1.87

Abbreviations: A = angry child, BA = bully and attack, CS = compliant surrender, DP = detached protector, DPa = demanding parent, DS = detached self‐soother, E = enraged child, H = happy child, HA = healthy adult, I = impulsive child, NSM = negative schema modes, PN = participant number, PP = punitive parent, PSM = positive schema modes, SA = self‐aggrandizer, U = undisciplined child, V = vulnerable child.

^a Significant positive reliable change (> 2 for the NSM; < −2 for the PSM).

^b Significant negative reliable change (< −2 for the NSM; > 2 for the PSM).

3.3.3. Negative and Positive Schemas

There was no significant decrease in negative schemas as measured by YSQ (t = 1.841, p = 0.115), as shown by a paired samples t‐test. The RCI of the subscales of the YSQ was calculated based on psychometrics in a Dutch clinical sample (Rijkeboer et al. 2005). The results indicate that one of the scores (1%) demonstrates negative reliable change, whereas 33 of the 112 scores (29%) demonstrate positive reliable change. This is presented in Table 10.

TABLE 10.

RCI of the YSQ pre‐post‐test of the sub‐scores.

PN	Dep	SU	FtA	SI	D	A	ED	M/A	I‐SC	En	US	EI	SS	S	E	VtH
2	0.43	−0.77	0.89	−0.27	0.00	0.70	0.00	1.33	0.00	0.24	1.99	1.45	3.33 a	0.00	4.45 a	0.40
3	2.00 a	1.25	1.44	0.53	3.44 a	3.52 a	4.83 a	−0.42	2.01 a	1.70	2.20 a	0.36	1.85	2.25 a	0.00	1.85
6	0.87	0.25	−1.75	0.80	0.65	−1.59	1.16	0.19	0.99	−1.70	−0.38	−2.58 b	1.66	0.25	0.98	−1.24
7	1.13	0.50	0.00	−0.27	0.23	1.75	−0.28	−0.19	0.78	1.46	0.56	0.73	−0.53	0.50	−1.47	2.08 a
8	2.67 a	2.52 a	3.19 a	3.47 a	3.89 a	2.83 a	1.99	2.10 a	3.01 a	1.93	3.10 a	2.91 a	3.14 a	3.50 a	1.47	2.66 a
9	−0.23	0.00	0.29	0.00	0.23	−0.35	−0.28	−0.39	−0.39	−0.48	−0.94	0.00	−1.63	0.00	0.00	0.00
10	2.23 a	3.02 a	2.04 a	3.47 a	3.24 a	2.13 a	5.35 a	−0.84	1.98	2.17 a	4.77 a	3.30 a	1.29	1.50	1.49	1.65

Abbreviations: A = abandonment, D = defectiveness/shame, Dep = dependence, E = enmeshment, ED = emotional deprivation, EI = emotional inhibition, En = entitlement, FtA = failure to achieve, I‐SC = insufficient self‐control, M/A = mistrust/abused, PN = participant number, S = subjugation, SI = social isolation, SS = self‐sacrifice, SU = social undesirability, US = unrelenting standards, VtH = vulnerability to harm.

^a Significant positive reliable change (> 2).

^b Significant negative reliable change (< −2).

A Wilcoxon signed‐rank test revealed a statistical increase in positive schemas between baseline and follow‐up, as measured with the YPSQ (z = 2.028, n = 7, p = 0.043), with a small effect size (r = 0.290; see Table 6). Table 11 presents the RCI outcomes of the subtests of the YPSQ, based on psychometrics in a Dutch non‐clinical sample (Ouwens et al. 2025). Forty‐five of the scores (45%) exhibited positive reliable change, whereas 3 of the 98 scores (3%) demonstrated negative reliable change.

TABLE 11.

RCI of the YPSQ pre‐/post‐test of the sub‐scores.

PN	EF	S	EC	BH	EOS	SC	HB	SB	HSC	RE	SD	HS	SA	HSR
2	−2.90 a	−1.34	−2.72 a	−0.97	1.79	−1.33	−1.21	7.44 b	−1.80	0.00	−1.77	0.07	−2.46 a	2.50 b
3	−1.62	−0.67	−2.72 a	−5.31 a	−1.41	−3.59 a	−1.21	−0.62	0.60	1.08	−2.47 a	−2.20 a	−3.52 a	−2.57 a
6	−2.90 a	−5.35 a	−4.76 a	1.18	−1.28	−0.63	−1.67	−0.62	−3.00 a	0.00	−2.47 a	−0.82	−0.59	−1.67
7	2.32 b	−0.67	−0.68	−2.95 a	−0.77	0.63	−2.41 a	−2.48 a	0.48	−1.20	0.00	−2.20 a	−1.29	−3.50 a
8	−4.06 a	−7.36 a	1.36	−5.90 a	−1.92	−0.63	−5.17 a	2.95 b	−0.60	−1.20	−3.53 a	−0.22	−3.63 a	−3.25 a
9	−1.16	0.67	−4.08 a	−2.36 a	−3.07 a	−1.27	−1.72	−1.24	−2.40 a	−3.59 a	−0.47	−0.66	−0.47	−0.75
10	−4.06 a	−2.68 a	−5.98 a	−5.31 a	−6.39 a	−4.22 a	−3.96 a	−3.10 a	−1.68	−4.78 a	−4.00 a	−1.54	−4.69 a	−5.00 a

Abbreviations: BH = basic health and safety/optimism, EC = empathic consideration, EF = emotional fulfilment, EOS = emotional openness and spontaneity, HB = healthy boundaries/developed self, HS = healthy self‐interest/self‐care, HSC = healthy self‐control/self‐discipline, HSR = healthy self‐reliance/competence, PN = participant number, RE = realistic expectations, S = success, SA = stable attachment, SB = social belonging, SC = self‐compassion, SD = self‐directedness.

^a Significant positive reliable change (< −2).

^b Significant negative reliable change (> 2).

3.3.4. PD

To compare the mean total score of the number of PD criteria at baseline versus after treatment, a paired samples t‐test was conducted. There was a significant decrease in the scores after treatment with a large effect size (t = 6.352, p < 0.001, Cohen's d = 2.401; see Table 8). All seven participants that completed the study did not meet the full criteria for DSM‐5 PD anymore after treatment, as measured with the SCID‐5‐P. The number of identifiable criteria on an obsessive–compulsive, dependent or avoidant PD varied from 0 to 3.

4. Discussion

The aim of this study was to assess the efficacy of an adapted form of ST for older adults as a treatment for Cluster C PDs. Specifically, this study aimed to examine whether older patients with Cluster C PDs benefit from an adapted form of ST. The primary objective of the study was to examine the effect of adapted ST on the credibility of both positive and negative core beliefs. The hypothesis was that the strength of negative core beliefs would reduce and the strength of positive core beliefs would increase in the treatment and follow‐up phases in comparison to the baseline phase. The visual inspection indicated that there were mixed results per participant. Positive core beliefs increased significantly in three out of eight (38%) participants between baseline and treatment and in three out of six (50%) participants between baseline and follow‐up. Effect sizes were all very large when a significant increase occurred. For negative core beliefs, two out of eight (25%) participants reported a significant decrease in the credibility of negative core beliefs when the baseline phase was compared to the treatment phase, and four out of six (67%) participants reported this significant decrease when the baseline phase was compared to the follow‐up phase. Effect sizes ranged from medium to very large when a significant decrease occurred. At the group level, results showed that for positive core beliefs, there were a non‐significant increasing trend in the baseline versus treatment phase and a significant effect in the baseline versus follow‐up phase, indicating that the pattern of individual effects showed a significant effect at the group level with a very large effect size. For negative core beliefs, a statistically significant reduction in the credibility of the negative core beliefs between the baseline and treatment phase and follow‐up phase at the group level was shown, again with very large effect sizes.

The secondary objective was to explore whether there were a reduction in the levels of distress and dysfunctional schemas and modes and an increase in positive schemas and modes in the follow‐up phase in comparison to the baseline phase. Despite the limited sample size (n = 7) and therefore under‐powered, the results indicated a statistically significant reduction in symptomatic distress with medium effect size and a statistically significant increase in positive schemas with small effect size. This finding aligns with the RCI, which indicated that 71% of participants exhibited significant reliable positive change on symptomatic distress and 45% on positive schemas. No significant findings were identified with regard to positive and negative modes or negative schemas, although effect sizes were small to medium. This finding is further substantiated by the RCI, which exhibited a positive reliable change in 21% of positive schema modes, 38% of negative schema modes and 29% of negative schemas. All seven participants no longer met the full criteria for DSM‐5 PD after treatment. A significant decrease in PD criteria was observed following treatment, with a large effect size.

Videler et al. (2018) also employed a multiple baseline design study for ST in eight older adults with Cluster C PD, but the study did not include positive schemas. The design was similar as in the current study: baseline, followed by one ST treatment, and a subsequent 6‐month follow‐up with primary outcome the credibility of negative core beliefs. In Videler's study, no individual tests were conducted per participant, but effect sizes where calculated on a group level using mixed regression analysis. The group effect demonstrated a significant decrease in negative core beliefs following treatment and subsequent follow‐up (both p < 0.001), exhibiting small to very large effect sizes (d = 5.028 and d = 0.411, respectively). Compared to the current study, the effect sizes of negative core beliefs after treatment with the addition of positive schemas are both very large, but smaller than the Videler et al. (2018) study. Hypothetically, this discrepancy could be attributed to the higher prevalence of personality problems and heterogeneity observed in the present study (M = 24.429, SD = 8.364) compared to Videler's study (M = 13.71, SD = 2.69). However, after follow‐up, the effect size of negative core beliefs in the present study is very large, but Videler's study showed a small effect size. This suggests that the addition of positive schemas leads to more favourable outcomes in the longer term.

This study has several strengths and limitations. The first limitation of this study is that the design does not allow for differentiation between the separate effects of adding positive schemas and other adjustments to ST. A second limitation is the selection of the positive core beliefs. We instructed the participant to select the highest scoring positive schema and deduct positive core beliefs from that. The intervention was aimed at increasing the already high schema, so a ceiling effect is very likely. For future research, we recommend aiming at positive schemas that were active at the specific period at which their psychosocial functioning was most optimal. An important indication of its potential can be seen in the significant increase in the YPSQ, which includes all positive schemas, not just the highest scoring ones. A final limitation is that we used only three techniques aimed at (re)building positive schemas. Possibly, other techniques could add more or additional effects. However, techniques aimed at building or reactivating positive schemas are new in ST.

One of the study's key strengths is the multiple baseline design, which allows for the demonstration of significant changes in a smaller number of participants. This is despite the possibility of such changes being attributed to the passage of time (Onghena 2005). Another strength is the use of idiosyncratic beliefs as the primary outcome measure, which ensures that the core belief is as close as possible to the participant's EMS. This is a key element in ST, according to Young et al. (2003).

To the best of our knowledge, this is the first empirical study to integrate positive schemas—or EAS—in adapted ST treatment for older adults. This is consistent with broader developments that support the integration of positive schema work into ST (Louis et al. 2024; Louis et al. 2023; Louis et al. 2018; Videler et al. 2020). The incorporation of positive schemas has the potential to enhance the efficacy of ST in older adults, as they have had more time to develop positive schemas during periods of their lives when they functioned better. Integrating positive schemas into ST for older adults is relevant because, at present, there is a discrepancy between the theoretical understanding of positive schemas and their practical application. This study offers preliminary insights into the potential efficacy of positive schemas in ST. It is also relevant because our knowledge about the treatment of PDs in this age group is still growing, and this adds to the body of evidence for this population. Research on treatment for PDs has focused mainly on adults so far (van Dijk et al. 2023). Yet, given the substantial increase in the number of older people in Western and Asian populations, including the group of older adults with PDs, more research is needed that covers the full lifespan. The findings of the current study are promising and provide valuable leads for this age group.

This study represents the initial empirical investigation of an adapted ST protocol for older adults, with a focus on (re)building positive schemas. As such, this study entailed an examination of the protocol's effects in a small sample of older adults. A subsequent step would be to conduct qualitative research to examine the impact of addressing positive schemas in the lived experience of patients and therapists. This can contribute to a broader span of interventions aimed at (re)building positive schemas. Consequently, a more extensive study can be conducted to replicate the current findings and ascertain more robust evidence for the hypothesis by means of an RCT. The Level of Personality Functioning Scale—Brief Form 2.0 (LPFS‐BF 2.0) (Weekers et al. 2019), a questionnaire developed for the purpose of measuring personality functioning, could be employed as an alternative to the credibility of core beliefs. Moreover, examining the additional effects of the adapted ST in both younger and older adults is recommended, as research shows that adolescents and younger adults also benefit from positive interventions (Carr et al. 2021; Tejada‐Gallardo et al. 2020). It would be beneficial to study EAS, not only in Cluster C PDs but also in Cluster B PDs, as Cluster B PDs do persist into old age, although the expression of these disorders changes in later life (Videler et al. 2019). It is important to include follow‐up effects in future studies, as preliminary results indicate that the incorporation of positive schemas in ST might lead to enhanced therapeutic outcomes in the long term. Finally, it is recommended that positive schemas or positive aspects of the self in older adults be further explored within other forms of psychotherapy. Given that older adults have frequently exhibited periods of enhanced functionality and positive schemas were active during those periods, this could be a significant target for treatment in other psychotherapy forms as well.

The results of this study show first indications of the effectiveness of adding positive schemas to ST as usual and to the benefits for the effectiveness of adapted ST for older adults as well. Further research is required in order to evaluate whether these effects of incorporating positive schemas in ST can be further substantiated and reproduced.

Ethics Statement

The trial is registered in the Netherlands National Trial Register NL8346, registered 1 February 2020. It is approved by the Medical Ethical review board Brabant (Medische Ethische Toetsings Commissie Brabant) under NL 71769.028.19.

Conflicts of Interest

The authors declare no conflicts of interest.

Supporting information

Figure S2 Plot of the mean negative and positive core beliefs of Participant 2.

Figure S3: Plot of the mean negative and positive core beliefs of Participant 3.

Figure S4: Plot of the mean negative and positive core beliefs of Participant 4.

Figure S5: Plot of the mean negative and positive core beliefs of Participant 5.

Figure S6: Plot of the mean negative and positive core beliefs of Participant 6.

Figure S7: Plot of the mean negative and positive core beliefs of Participant 7.

Figure S8: Plot of the mean negative and positive core beliefs of Participant 8.

Figure S9: Plot of the mean negative and positive core beliefs of Participant 9.

Figure S10: Plot of the mean negative and positive core beliefs of Participant 10.

van Donzel, L. , Ouwens M., van Alphen S., Bouwmeester S., Bachrach N., and Videler A.. 2025. “Integrating Positive Schemas in Schema Therapy for Cluster C Personality Disorders in Older Adults: A Multiple Baseline Study.” Clinical Psychology & Psychotherapy 32, no. 4: e70121. 10.1002/cpp.70121.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.