Assessment of personality functioning in psychosomatic medicine

Patients in consultation-liaison psychiatry, psychotherapy, and psychosomatics are often regarded to be difficult to treat. Their impairments in the realms of emotion regulation and interpersonal relationships, frequently combined with an unhealthy lifestyle and few adaptive health-related behaviors, lead to challenges for healthcare professionals.

Personality functioning—amongst others also referred to as structural integration or personality organization [1]—describes basic self-related and other-related affect-laden processing and regulation capacities. Patients suffering from impairments in personality functioning—at worst resulting in personality disorder [2]—show significantly reduced psychosocial functioning, which includes difficulties in self-regulation and the regulation of interpersonal relationships. Personality functioning is assumed to vary on a continuum ranging from non-impaired/well-integrated to severely impaired/disintegrated levels [2‐4]. The severity of personality pathology is defined by the degree of disturbances in self and interpersonal functioning [5]. Personality functioning on a well-integrated level is characterized by a coherent sense of self, flexible functioning even when stressed by external or internal conflicts, appropriate expression and regulation of impulses and emotions, internalized moral values and engagement in satisfying relationships [4, 5]. Individuals at lower levels of personality functioning typically display, amongst others, characteristic problems in self-regulation or self-other differentiation (i.e., the attribution of mental states to the self or another person), which are accompanied by a range of challenges related to adverse health behaviors and interpersonal relations, including the doctor-patient relationship [6]. In the clinical setting, patients with lower levels of personality functioning are often experienced as “difficult to treat” [7]. Consequently, the focus on domains beyond symptoms, such as personality functioning, has been emphasized as being highly important for indications and treatment planning [8]. Despite the theoretical and practical significance of the personality functioning concept, it is not yet commonly integrated into diagnostic and treatment processes.

The concept of personality functioning is represented in a range of contemporary models for the description of variation in personality and personality pathology, including the DSM‑5 alternative model of personality disorders (AMPD, [2]) and the upcoming ICD-11 dimensional personality disorders model [9], the operationalized psychodynamic diagnosis (OPD) levels of structural integration axis (LSIA, [4]), or the model of personality organization proposed by Kernberg et al. with the corresponding structured interview of personality organization (STIPO, [3]). Beyond that, similar concepts are represented in nonclinical personality models aiming to describe variation in basic emotion-related processing and regulation capacities (here referred to as emotional intelligence, or competence), pointing to the ubiquity of the concept across different research and applied traditions [10]. All of these models share the idea that personality functioning, structural integration, personality organization, or emotional competence, describe fundamental emotion-related capacities underlying more specific aspects of personality. These fundamental aspects are discernible from (although not independent of) more specific patterns of experience and behavior describing the individual’s propensity to feel and act in a particular manner [10]. This latter aspect is, depending on the psychological tradition, either described in terms of prevailing conflicts (such as in the OPD system) or personality traits (such as in the DSM‑5 and ICD-11 systems). For instance, a narcissistic personality style would be regarded as a manifestation of a prevailing conflict in the OPD system (conflict within the self-esteem system [4]) and combination of descriptive traits (facets of antagonism) in the DSM‑5 system [2]. The level of intrapersonal and interpersonal functioning on which the—in this example narcissistic—individual operates would be considered an indicator of personality functioning, ranging from no impairment to severe impairment [2, 8]. In this line of thinking, it is thus the level of personality functioning (the A criterion in the DSM‑5 AMPD, [2]), rather than the more specific aspects of personality, that informs about the severeness of impairments.

Personality functioning is commonly assessed by trained clinicians or researchers using standardized or semi-standardized interviews, such as the previously mentioned STIPO [3], the OPD interview [4, 8] or the structured clinical interview for the AMPD [11]. All of these have been found to be reliable and valid diagnostic assessments, which predict an array of general clinically relevant outcomes, such as number of diagnoses, symptom load and global functioning [8]. Expert interviews can be complemented by self-report measures of personality functioning, which have been developed for all systems (e.g. [12]).

Historically, the dimension of personality functioning has been part of psychoanalytic and psychodynamic theory and research since Sigmund Freud presented his first structural model in 1900 [13]. Later on he defined health as being able to love and to work. These capacities can be regarded as the precursors of what we now call personality functioning; the functions of the ego help an individual adjust and adapt to his or her reality. Personality functioning becomes apparent in the shape of capacities of the self. These include self and other recognition, regulation, communication, and attachment. The interaction within the parent-child dyad as our first environment—as an intersubjective encounter that predisposes the development of self and the other—modulates the organization of our body-mind interoceptive and exteroceptive connections in relation to the other [14]. Our environment is bound to what we experience; we change in the light of the picture we make of ourselves. Otto Kernberg developed an influential systematic model of personality functioning, for which he coined the term personality organization [15]. According to his model, personality organization is reflected through five domains of functioning: the coherence of identity, the quality of object relations, the maturity of defense mechanisms, aggression, and moral values [15]. Based on these domains of functioning, Kernberg differentiates between a healthy/mature, a neurotic, a borderline, and a psychotic personality organization [16]. A similar model is implemented in the OPD system, where the LSIA incorporates theories from ego-psychology, self-psychology, object relations theory and developmental psychology in terms of core capacities in perception, regulation, communication and attachment [17]. Each of these core capabilities can be directed towards the self and towards others, leading to a total of eight dimensions (see Table 1). A similar model has been established in the DSM‑5 AMPD, where the two large domains self and interpersonal functioning are parted in (roughly speaking) perceptual (identity and empathy) and regulatory (self-direction and intimacy) aspects (see Table 1). Finally, a model has been proposed for the upcoming ICD-11 ([9], see also [18]). To sum up, several contemporary models of personality functioning assume that self-related and other-related affect-laden information processing and regulation capacities make up the basis on which more nuanced personality characteristics operate. This basis ranges from well-integrated with no impairment to disintegrated structures with severe impairment in functioning, which is of high diagnostic relevance for mental and also physical health, as discussed in the following.

The assessment of personality functioning has become increasingly important in psychiatric diagnostics for indication and treatment planning [19]. As mentioned before, the impairment of personality functioning represents the primary criterion of the DSM‑5 AMPD. A recent study investigated emotional experiences in patients with major depressive disorder, comparing groups with and without comorbid borderline personality disorder to each other. It was investigated whether depression severity or personality functioning would mediate group differences, and which aspects of emotional experience change during psychotherapy. Lower levels of personality functioning in depressed patients with borderline personality disorder (BPD) were associated with a broader spectrum of negative emotions [20].

In patients with bipolar disorder, a low level of personality functioning and an insecure attachment style was accompanied by a significantly higher symptom load [21].

Schneider et al. compared male and female patients with respect to the OPD‑2 system, treatment variables and outcome after multimodal psychodynamic inpatient psychotherapy. There were differences between men and women in the main diagnoses, with a higher proportion of eating disorders and a longer treatment duration among women. Therapy discontinuation rates were low and did not differ between the sexes. Overall, both sexes seem to benefit equally from psychodynamic inpatient psychotherapy in terms of symptom improvement [22].

According to biopsychosocial medicine, psychosocial aspects may be relevant in pathogenesis, triggering or maintaining multiple somatic symptoms and diseases. Personality functioning may therefore be one relevant factor contributing to health and disease. Reduced personality functioning goes along with reduced core capacities in perception, regulation, communication, and attachment; for example, there are deficits in experience, verbal expression, and regulation of emotion [23]. Such impairments in self and interpersonal functioning may impact on coping strategies, emotion regulation and stress [24, 25]. Via stimulation of stress-regulating systems like the hypothalamic-pituitary-adrenal axis or the autonomic nervous system, but also via alterations of the immune system, a chronic activation of these systems results in their dysregulation and may finally lead to aggregate physiological and mental consequences [26, 27]. We therefore suggest that there is a link between personality functioning and physical as well as mental health, including affective dynamics such as depressive, anxiety, and somatization symptoms in patients with somatic diseases [28]. Interrelations between personality functioning and health might also be mediated via adverse health behavior and lifestyle [29]. Furthermore, problems in forming and regulating interpersonal relationships including the doctor-patient relationship may impact on the course of diseases and adherence to treatment [7].

In the following sections, studies assessing personality functioning in various medical fields are reviewed. Starting from the field of internal medicine, we will continue with the phenomenon of chronic pain and development of postoperative pain and finally review studies from the field of transplantation medicine.

As the available systematic evidence on the role of personality functioning is psychosomatic medicine is limited, we complement our review by a short discussion on findings on BPD in this field. The BPD, also known as emotionally unstable personality disorder, is a severe mental disorder with significant impairments in personality functioning. Common problems include difficulties in regulating emotions and impulses, intense and unstable interpersonal relationships and an inconsistent sense of self. In the DSM‑5 model of personality disorders, general criteria and the severity of personality disorders are closely linked to such impairments in self and interpersonal functioning. From a psychodynamic point of view, it is assumed that pathology and severity of personality disorders in general and of BPD in particular are determined by the degree of structural impairment. Therefore, BPD reflects the single personality disorder diagnosis which most closely resembles impairments in general personality functioning, rather than specific traits (such as for instance narcissistic or histrionic personality disorders). Although a BPD diagnosis and a personality structure at the borderline functioning level are not identical, they are largely overlapping. For example, a study among a sample of 104 patients with a clinical diagnosis of BPD and an assessment of personality organization using the STIPO revealed that all patients were classified at a level of borderline personality functioning. Furthermore, more clinically severe forms of BPD were linked to a lower level of personality functioning [46].

It has been proposed that one way of bringing psychodynamic concepts and neuroscience together could be via the OPD, as this instrument provides both an expanded view of individual psychological content and a systematic reduction of content that is necessary for experimental settings [53]. That way, it would also serve as an option to individualize experiments [54]. The authors propose that “only if the experiment touches the mentally represented themes that are of individual relevance to each subject, results could have validity and meaning in a deeper sense” [55]. The OPD could therefore be used for gathering individualized information in a systematic way and it could also be helpful in interpreting brain activity on a psychodynamic level. For example, in such an individualized paradigm Kessler et al. presented individual stimulus sentences that had been gathered via OPD to 29 healthy female subjects who freely associated to these stimuli while being in an Magnetic Resonance Imaging (MRI) scanner [56]. Associations to conflict-related sentences were associated with several behavioral and psychophysiological correlates that correspond with the concept of repression, a central defense mechanism in psychodynamic theory. Recently, a neurobiologically and clinically grounded model of personality organization has been introduced. This so-called neuropsychodynamic model relates the psychodynamic model of personality functioning, the construct of the self and its neuronal correlates to each other [57]. Empirical data on neuronal correlates of the self suggest that early relational and attachment experiences as well as the brain’s resting state activity relate to the concept of the self. The authors propose a multilayered model of the self, with four different layers (relational alignment, self-constitution, self-manifestation, and self-expansion) that are associated with different neuronal correlates, corresponding to different levels of personality organization including neurotic and borderline organization. That way, the psychodynamic concept of personality organization could also be linked to the concept of the self and its neuroscientific correlates; however, future research will show if this novel neuropsychodynamic model of personality organization will find further empirical support.

Only a limited number of studies in psychosomatic medicine included an assessment of personality functioning so far. Whereas for patients with borderline personality disorder (BPD) several studies confirmed high somatic comorbidity, unhealthy lifestyle choices, negative perception of health and adherence problems, little is known about patients whose impairments in personality functioning do not meet the criteria of a diagnosis of personality disorder. Regarding pain perception, chronic pain was found to be associated with a lower level of personality functioning [36]. While acute postoperative pain was lower in patients with impairments in personality functioning, chronic postoperative pain was predicted by lower personality functioning [43]. Health conditions such as diabetes or after organ transplantation, that require enduring changes in health behavior, might be difficult to manage for patients with impairments in personality functioning [7]. While this might be experienced as a lack of adherence in the clinical encounter, an important implication of the reviewed studies for clinicians is to consider impairments in personality functioning as a potential source of adherence problems in their patients. In eating disorders, an assessment of personality functioning could be used for selecting appropriate psychotherapeutic treatment strategies, as some subtypes of eating disorders are associated with different levels of structural integration [33].

In the psychiatric as well as in the somatic setting, patients with impairments of personality functioning present with self-regulation disturbances and relationship difficulties. The assessment and characterization of personality and attachment styles may be of particular value in identifying individuals who may respond to certain forms of psychotherapeutic treatment. These patients may need more information about their illness and medication; they may benefit from more frequent appointments and a more proactive attitude of the therapist or doctor. The self-awareness of patients with impairments in personality functioning should be improved by therapeutic interventions targeting self-awareness and teaching strategies and skills for regulating emotions and relationships. Finally, they may benefit from interventions designed to foster a healthy lifestyle.

Summing up, results so far underline the importance of assessing personality functioning for diagnosis and planning of psychotherapeutic treatment for somatically ill patients. An assessment of personality functioning could be helpful in several fields of psychosomatic medicine including therapy of chronic pain and adherence to treatment in chronic conditions; however, more empirical studies are needed to prove the appropriateness of these assumptions.