Administrative information
Title {1} | Individual Psychotherapy for Cluster-C Personality Disorders: Protocol of a pragmatic RCT comparing Short-term Psychodynamic Supportive Psychotherapy, Affect Phobia Therapy and Schema Therapy (I-FORCE) |
Trial registration {2a and 2b}. | NL72823.029.20 [Registry ID: CCMO]. Registered on 20-08-31 ICTRP: NL8545 [International Clinical Trials Platform]. Registered on 2020-04-20 |
Protocol version {3} | Version 3, January 2023 |
Funding {4} | This research is funded by Arkin Mental Health Care. |
Author details {5a} | M. Daniëls, MSc: Arkin Mental Health Care, the Netherlands H.L. Van, PhD: Arkin Mental Health Care, the Netherlands B. van den Heuvel, MSc: Arkin Mental Health Care, the Netherlands Prof. J.J.M. Dekker, PhD: Department of Clinical Psychology, VU University of Amsterdam, the Netherlands J. Peen, PhD: Arkin Mental Health Care, the Netherlands Prof. J.E. Bosmans, PhD: Department of Health Sciences, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam Public Health research institute, The Netherlands Prof. A. Arntz, PhD: Department of Clinical Psychology, University of Amsterdam, the Netherlands Prof. M.J. H. Huibers, PhD: Utrecht University, Department of Clinical Psychology, and Arkin Mental Health Care, the Netherlands) |
Name and contact information for the trial sponsor {5b} | H.L. Van, PhD: NPI, Arkin Mental Health Care, Domselaerstraat 128 1093 MB Amsterdam, the Netherlands, rien.van@arkin.nl |
Role of sponsor {5c} | This funding source (Arkin Mental Health Care) had no role in the design of this study and will not have any role during its execution, analyses, interpretation of the data, or decision to submit results. |
Introduction
Background and rationale {6a}
Cluster-A PDs (paranoid, schizoid and schizotypal PD) are considered to be the odd, eccentric disorders. | |
Cluster-B PDs (borderline, narcissistic, histrionic, antisocial PD) are characterized by thoughts and emotions that are dramatic and overly emotional. | |
Cluster-C PDs (avoidant, compulsive, dependent PD) are characterized by anxiety and fear (DSM-V, APA, 2013). |
Evidence from previous trials
Explanation for the choice of comparators {6b}
Psychotherapies
Process research
Potential mediators
Potential predictors
-
Childhood trauma: Childhood traumatic events are assumed at least partially to underlie the development of personality pathology, and adequately processing is helpful to reduce these problems [5, 6]. It has been identified as a negative predictor of treatment outcome for different psychiatric disorder [79],
-
Level of autism traits: There is a high comorbidity and considerable overlap in symptoms between autism and PDs [69, 100]. Lugnegård et al. [70] found about half of the participants with an autism spectrum disorder (ASD) also met criteria for a PD, all belonging to Cluster-A or C. Effectiveness of psychotherapy for patients with PD and comorbid autism traits has not been studied, but Weston et al. [102] found lower effectiveness of treatment (cognitive behavioural therapy) of affective disorders within patients with ASD.
-
Personality organization as defined by Kernberg [57]: The level of personality organization is defined by three domains: identity, primitive defence mechanisms, and reality testing. The severity of the personality pathology is ranging from neurotic personality organization to borderline personality organization to psychotic personality organization, the latter one being the most severe group of patients. Higher levels of personality organization are related to better treatment outcome [61]. Overall, in Cluster-C PDs, higher levels of personality organization were found than for Cluster-A or B PDs [29]. Until now, personality organization within Cluster-C patients and its impact on outcome has not been investigated.
-
Vulnerable narcissism: Vulnerable narcissism is mainly manifested in the avoidant and obsessive-compulsive PD [76, 81] and is related to avoidant attachment and maladaptive, impulsive and avoidant ways of coping with stress [54]. No studies are available on the effectiveness of patients with Cluster-C PD and vulnerable narcissism, but vulnerable narcissism might be related to negative treatment outcome.
Objectives {7}
Trial design {8}
Methods: participants, interventions and outcomes
Study setting {9}
Eligibility criteria {10}1
Inclusion criteria
-
Primary diagnoses: DSM-V diagnosis Cluster-C PD or Otherwise specified PD with predominantly Cluster-C traits, operationalized as a minimum of 5 Cluster-C traits (see Table 2 for examples of Cluster-C traits)
-
Age 18–65 years
-
A written informed consent
-
Dutch literacy
-
The willingness and ability to participate in an individual treatment of 50 sessions in 1 year.
Avoidant PD: | |
● Avoids occupational activities that involve significant interpersonal contact because of fears of criticism, disapproval or rejection. | |
● Views self as socially inept, personally unappealing, or inferior to others. | |
Dependent PD: | |
● Needs others to assume responsibility for most major areas of his or her life. | |
● Feels uncomfortable or helpless when alone because of exaggerated fears of being unable to care for himself or herself. | |
Compulsive PD: | |
● Shows perfectionism that interferes with task completion. | |
● Is overconscientious, scrupulous, and inflexible about matters of morality, ethics or values (DSM-V, APA, 2013) |
Exclusion criteria
-
(Subthreshold) Cluster-A or B PD
-
Having received SPSP, APT or ST in the previous year
-
Immediate intensive treatment or hospitalization is needed, e.g. acute suicidality
-
Severe psychiatric disorder requiring priority in treatment (autism spectrum disorder, psychotic symptoms/disorder, bipolar disorder, severe substance use disorder)
-
IQ <80. This will be assessed by the recruiting/intakers who carry out the eligibility assessments. When they suspect an IQ < 80 (mental retardation), standard procedure in the NPI is to conduct further diagnostic procedures on intelligence.
Therapists
Interventions
Intervention description {11a}
Criteria for discontinuing or modifying allocated interventions {11b}
Strategies to improve adherence to interventions {11c}
Relevant concomitant care permitted or prohibited during the trial {11d}
Provisions for post-trial care {30}
Outcomes {12}2
Assessment and outcome measures
Primary outcome measure
-
Assessment of DSM-IV Personality Disorders questionnaire (ADP-IV, [87]). The primary outcome is the severity of Cluster-C personality pathology, measured by the ADP-IV. The ADP-IV is a self-report questionnaire, assessing DSM-IV PD criteria. Patients indicate on a 7-point Likert scale to what degree PD criteria hold for them, ranging from 1 (‘not at all’) to 7 (‘completely’), and whether they experience distress from it (on a range from 1—not at all to 3—definitely). Item construction of the ADP-IV allows for both dimensional and categorical diagnostic evaluation [87]. Adequate internal consistency, validity and reliability were shown consistently in previous studies [30, 85].
Secondary outcomes
Personality functioning
-
The Structural Clinical Interview for DSM-5 Personality disorders (SCID-5-P, [7]). This Dutch version of the SCID-5-P is used for diagnosing PDs at assessment and at 1-year follow-up. The SCID-5-P replaced the SCID-II. The exact reliability and validity of this version of the SCID-5-P is still unknown. Previous research, however, has shown adequate to good interrater reliability and test-retest interrater reliability of the original SCID-II, the Dutch version and translations of the SCID-5-P in other languages [42, 66, 71, 90]. Assessment using the SCID-5-P will be guided by items previously affirmed by the patient on SCID-5-PV (Structured Clinical Interview for DSM-5 Personality Questionnaire), a self-report questionnaire screening for PDs that will be completed at intake. Items not affirmed on the SCID-5-PV will be assumed to be true negatives; however, if a clinician has reason to believe these are false negatives, such items will be assessed. This method is in accordance with instructions for using the SCID-5-P and enables the assessment of PD symptoms to be based upon self-report combined with a structured clinical interview.
-
Avoidant Personality Disorder Severity Index (AVPDSI) Dependent Personality Disorder Severity Index (DEPDSI), Compulsive Personality Disorder Severity Index (OCPDSI). These semi-structured interviews are developed to assess the frequency and severity of manifestations of the DSM-5 criteria of avoidant, dependent and compulsive PDs. For patients with a main diagnosis otherwise specified PD with predominantly Cluster-C traits, a personalized selection of the Cluster-C traits derived from the AVPDSI, DEPDSI and OCPDSI is made. These interviews have excellent interrater agreement (ICC>.90) and internal consistency (Cronbach a>.90) [44]. The interviews are modelled after the Borderline Personality Disorder Severity Index (BPDSI), measuring the severity of BPDs. The BPDSI is a reliable and valid instrument, suitable for use as an outcome measure [8, 43]. Total scores of the AVPDSI, DEPDSI and OCPDSI consist of a total sum of the average symptom scores per subsection of the interview, an average burden score and an average impact score. The scores on the instruments are converted into one severity score by standardizing the raw scores (see Groot et al. [44] for a description of the calculations per interview). To ensure quality of data collection of the AVPDSI, DEPDSI and OCPDSI, assessors will be trained, and all measurements will be audiotaped.
-
Inventory of Personality Organisation Short Form (IPO-16-NL, [14]). The IPO-16-NL is the Dutch short version of the IPO-83 [21]. Norm scores of the German version are available and psychometric evaluation has shown good internal consistency, reliability, validity and confirmed a one factor structure of general personality dysfunction [107, 108]. The total score on the 16 items represents a dimensional measure of global severity of personality pathology according to Kernberg’s object-relationship framework.
Psychiatric symptoms
-
Brief Symptom Inventory (BSI, [26]). The BSI is a 53-item self-report instrument that will be used to measure general psychological distress. The answers are scored on a 5-point Likert scale. It is derived from the SCL-90-R and has demonstrated it to be an acceptable short alternative of its longer version [24].
Quality of life, happiness and psychosocial functioning
-
Quality of life (EQ-5D-5L, [48]). Quality of life is measured using the EQ-5D-5L. This self-report questionnaire assesses general quality of life using five domains: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 5 response levels: no/slight/moderate/severe/extreme problems. The Dutch norm scores will be used for calculating the mean EQ-5D utility values [99]. Psychometric study of the EQ-5D-5L has shown this version to be a valid and reliable extension of the three-level system [48, 52].
-
Happiness Question [98]. The Happiness Question is added as a single question on general happiness in the months prior to the assessment and is scored on a 7-point Likert scale. This scale consists of the following verbal descriptions of different states of happiness: (1) completely unhappy, (2) very unhappy, (3) fairly unhappy, (4) neither happy nor unhappy, (5) fairly happy, (6) very happy, (7) completely happy. Dutch norms are available. For a single happiness item, high test-retest reliability (r = .86) and good concurrent, convergent, and divergent validity have been reported. The Happiness Question [28] has excellent sensitivity to change for patients with borderline PD who were treated with group ST.
-
World Health Organization Disability Assessment Schedule (WHODAS 2.0, [95]). Psychosocial Functioning and Participation is administered with the WHODAS 2.0, a general measure of functioning and disability in major life domains, including understanding and communication, getting around, self-care, getting along with others, life activities and participation in society.
Costs
-
Treatment Inventory Cost in Psychiatric Patients (TiC-P, [97]). Societal costs are assessed using a specifically adapted version of the TiC-P. The TiC-P FORCE is a 14-item self-report questionnaire to assess health care costs (part I) and costs resulting from productivity losses (part II) associated with psychiatric disorders. In part I, the number of contacts with different health care providers over the last 6 months is assessed. Part II consists of items regarding absenteeism from paid and unpaid work and presenteeism (i.e. reduced productivity while at work) in the last 6 months.
Potential mediators
-
Working Alliance inventory-short revised (WAI-SR). The WAI-SR is a 12-item self-report measure of the therapeutic alliance that assesses three key aspects of the therapeutic alliance: (a) agreement on the tasks of therapy, (b) agreement on the goals of therapy and (c) development of an affective bond. The WAI-SR demonstrated good psychometric properties [77].
-
Difficult doctor-patient relationship questionnaire (DDPRQ-10, [45]). The DDPRQ-10 is a 10-item self-report questionnaire for therapists measuring the therapeutic relationship by investigating the extent to which patients are experienced as frustrating or difficult in the therapeutic relationship by their doctor or therapist. Five items are about the therapist’s subjective experience (e.g. “Do you find yourself secretly hoping that this patient does not return?”). Four items are quasi-objective questions about the patient’s behaviour (e.g. “How time consuming is care for this patient?”). One item combines elements of the patient’s behaviour and the therapist’s response (“To what extent are you frustrated by this patient’s vague complaints?”). The items are scored on a 6-point Likert scale. A high score reflects a high level of therapist frustration. In the study of Spinhoven et al. [91], the internal consistency of the DDPRQ-10 was .79.
-
The SMI-2 is a modified version of the SMI-1 self-report questionnaire [68]. It consists of 143 items on 18 schema modes that are scored on a 6-point Likert scale. It measures the extent to which dysfunctional as well as functional schema modes are present. Its subscales have satisfactory to high internal consistency (Cronbach’s α ranges from .79 to .96), and it is considered to be a useful instrument for assessing modes [67]. Newly formulated modes proved to be appropriate for histrionic, avoidant and dependent PD. In line with Yakın et al. [104], the Vulnerable Child and Healthy Adult mode will be analysed. The Avoidant Protector and Impulsive Child will be analysed exploratory. At baseline, the complete SMI-2 will be administered. A shortened version with the modes relevant for Cluster-C PDs is used for the repeated measurements.
-
Client Task-Specific Change Measure-R (CTSC-R, Watson et al: Client task-specific change measure–revised, unpublished). This is a 16-item client self-report on a 7-point Likert-type scale, designed to measure the extent to which clients are able to identify changes, or newly acquired insight associated with particular sessions. A total score on the scale provides an index of client change following the session. Total scores of five or higher are indicative of moderate to high amounts of self-perceived change. The instrument is validated by Watson et al. [101] and showed good psychometric qualities with high internal consistency and item total correlations. Factor analysis showed the instrument comprises two factors, one dominant factor conceptualized as behaviour change and a second minor factor conceptualized as awareness and understanding.
-
Level of discourse. The dominant level of discourse will be reported by the therapist at 1, 3, 6 and 9 months and at end of treatment, ranging from level 1 focusing on physical and psychological symptoms to level 8 focusing on the manifestation of the problems in the patient-therapist relation. This therapist-report scale is developed by Kool et al. [58].
-
Developmental Profile Inventory-Short Form (DPI-SF, [82]).The DPI is developed to assess psychodynamic personality functioning. It consists of nine subscales of developmental levels of psychodynamic functioning covering three domains: Self, Interpersonal Functioning and Defence/coping style. In this study, the DPI-SF consisting of the problem solving behaviour is being used to measure adaptive and non-adaptive defence styles. Internal consistencies of subsequent subscales were fair to good, ranging .71 to .91 in healthy controls and .67 to .88 in the patient sample. Mean corrected item total correlations were good, ranging .30 to .50. Test-retest reliability was good to excellent, with median intraclass correlation coefficient levels of .86 in healthy controls and .81 in the patient sample. The DPI also discriminated between patients and healthy controls in a meaningful way. Correlational analysis supported the distinction in a primitive and neurotic maladaptive cluster, and healthy adaptive cluster.
-
Brief Experiental Avoidance Questionnaire (BEAQ). The BEAQ is a 15-item self-report measure. It is the shortened version of the 62-item Multidimensional Experiential Avoidance Questionnaire (MEAQ, [41]), measuring experiential avoidance. Items are scored on a 6-point Likert scale. A high score reflects a high level of experiential avoidance. Gámez and his colleagues have developed the short version BEAQ, selecting the 15 best performing items of the MEAQ [40]. Initial validation of the BEAQ has demonstrated good psychometric qualities. The psychometric qualities of the Dutch BEAQ have recently been studied by Slagter F, Topper M, Kamphuis JH, Nugter A: Measuring experiential avoidance: psychometric properties of the Dutch multidimensional experiential avoidance questionnaire, in preparation.
-
Rosenberg self-esteem Scale (RSES). The RSES will be used to assess self-esteem. It is a widely used 10-item Likert scale self-esteem measure. Items are answered on a 4-point scale—from strongly agree to strongly disagree—measuring positive and negative feelings towards the self [84]. The Dutch version of the RSES is found to be a one-dimensional scale with high internal consistency and congruent validity and a Cronbach’s alpha of .89 [39].
-
I-FORCE Treatment Intervention List (I-FORCE-TIL). After each therapy session, therapists will indicate which interventions they used in that session on a 30-item intervention list. This list has been developed by the authors of this study (Daniëls and Van den Heuvel, [109], internal publication), indicating the core interventions per treatment (SPSP, APT and ST) on a dichotomous scale (yes/no). Aim of this assessment is to register the applied treatment procedure. Reliability and validity checks will be performed on the I-FORCE-TIL.
Potential predictors and moderators
-
Inventory of Personality Organization (IPO-83-NL, [50]). The IPO is a self-report instrument consisting of 83 items on a 5-point Likert scale, based on Kernberg’s structural model of personality organization [21]. The Dutch version of the IPO has three main scales (Identity Diffusion, Primitive Defence and Reality Testing) and two supplementary scales (Aggression and Moral Values). The IPO-83-NL has good reliability and validity and appears to be a useful instrument to measure general personality pathology [15].
-
Childhood Trauma Questionnaire-Short Form (CTQ-SF, [17]). This self-report measurement assesses childhood trauma. The short form was developed from the original 70-item version [16] and consists of 28 items measuring physical, sexual and emotional abuse and physical and emotional neglect. Its reliability and criterion-related validity have been established [17]. A recent study in the Netherlands confirmed its five-factor model [92].
-
Nederlandse Narcisme Schaal (NNS, [34]). The NNS measures three dimensions of narcissism: overt (‘centrifugal’) narcissism and covert (‘centripetal’) narcissism and isolation. The questionnaire consists of 35 items with a 7-point Likert scale. Covert narcissism is hypothesized to be present in some patients with a Cluster-C PD and could possibly influence the outcome. The construction of this subscale is based on the Dutch translation of the hypersensitive narcissism scale [47] and consists of 11 items, with good reliability (Cronbach’s alpha .82). Dutch norms are available, although further research is necessary.
-
Autism Spectrum Quotient short form (AQ-10). The AQ-10 Adult is derived from the original 50-item AQ [2], by a selection of the 10 items with the best discriminant validity. The questionnaire consists of 10 statements with for every statement four response options: strongly agree, slightly agree, slightly disagree, strongly disagree. At a cut-point of 6, sensitivity was .88, specificity was .91 and positive predictive value was .85.
Therapist adherence and competence
Treatment retention
Participant timeline {13}
Sample size {14}3
Recruitment {15}
Who will take informed consent? {26a}
Additional consent provisions for collection and use of participant data and biological specimens {26b}
Assignment of interventions: allocation
Sequence generation {16a}
Concealment mechanism {16b}
Implementation {16c}
Assignment of interventions: blinding
Who will be blinded {17a}
Procedure for unblinding if needed {17b}
Data collection and management6
Plans for assessment and collection of outcomes {18a}
Plans to promote participant retention and complete follow-up {18b}
Data management {19}
Confidentiality {27}
Plans for collection, laboratory evaluation and storage of biological specimens for genetic or molecular analysis in this trial/future use {33}
Statistical methods7
Statistical methods for primary and secondary outcomes {20a}
Primary study parameter(s)
Secondary study parameter(s)
Interim analyses {21b}
Methods for additional analyses (e.g. subgroup analyses) {20b}
Methods in analysis to handle protocol non-adherence and any statistical methods to handle missing data {20c}
Plans to give access to the full protocol, participant-level data and statistical code {31c}
Oversight and monitoring
Composition of the coordinating Centre and trial steering committee {5d}
-
Principal investigator: takes supervision of the trial and medical responsibility of the patients.
-
Data manager: organizes data capture, safeguards quality and data.
-
Study coordinator: trial registration, coordinates the study, annual safety reports.
-
Research assistants: identify potential recruits, take informed consent, conduct interviews and ensure follow-up according to protocol.
-
The research committee meets biweekly. There is no trial steering committee or stakeholder and public involvement group.