Intensive Short-Term Dynamic Psychotherapy for Functional Somatic Disorders: A Scoping Review

Abstract

Objective

Functional somatic disorders (FSD) are extremely common amongst neuropsychiatric and other specialty medicine referrals. Intensive Short-term Dynamic Psychotherapy (ISTDP) is an emotionally focused form of brief therapy that has been researched and developed specifically for the diagnostic assessment and treatment of FSD, amongst other conditions.

Method

In this publication, we review the ISTDP theoretical underpinnings, the diagnostic assessment, treatment approach and evidence base.

Results

There are now over 50 publications evaluating ISTDP and its effect and processes in FSD. It has been demonstrated efficacious for the spectrum of functional somatic disorders, including chronic pain, functional gastrointestinal disorders, and functional neurological disorders among others. It has further been found more effective than cognitive behavioral therapy in the treatment of chronic pain. Further there is evidence that it is cost-effective in treating these conditions.

Conclusions

ISTDP is a broadly useful clinical tool in the assessment and treatment of FSD.

Introduction

Somatic symptom and related disorders are one of the major categories of mental illnesses classified in DSM-5 These disorders are characterized by disproportionate thoughts, feelings, and behaviors related to somatic symptoms and include somatic symptom disorder, illness anxiety disorder, functional neurological symptom disorder (FND), and other related disorders (American Psychiatric Association, 2022). The prevalence of somatic symptom disorders is estimated to be around 4% to 6% in the general adult population (Creed & Barsky, 2004), with rates of 40-49% in primary care settings (Heidemarie Haller et al., 2015). In a study of hospital outpatient neurology, gastroenterology, Traditional Chinese Medicine [TCM] and psychosomatic medicine department in China, 33.8% of patients met the DSM-V criteria for somatic symptoms disorders (Jinya Cao et al., 2020).

Somatic symptom and related disorders are associated with high levels of emotional distress and low quality of life. In a population-based study in Taiwan, somatic symptom disorders and functional somatic syndromes were associated with significantly higher ratios for psychiatric hospitalization, all-cause hospitalization, suicide, mortality, medical costs and usage duration of all psychiatric medications and analgesics compared to the control group who did not have these diagnoses (Wu et al., 2024).

FND, formerly known as conversion disorder, manifests as various neurological symptoms which are unexplained by other traditional neurological or medical causes (Fobian & Elliott, 2019; Russell et al., 2022; American Psychiatric Association, 2022). These symptoms can include motor deficits like weakness or paralysis, abnormal movements, sensory alterations, and episodes resembling epileptic seizures or syncope. Diagnosis relies on clinical findings that are incompatible with known neurological diseases. These conditions are the second most common diagnosis in neurology clinics (Fobian & Elliott, 2019; Bennett et al., 2021). Stress, trauma, and early life experiences influence the development of emotional dysregulation and the manifestation of FND and functional somatic disorders (FSD).

Various biopsychosocial factors contribute to functional somatic symptoms amongst other persistent somatic symptoms. These include immune system factors, genetic factors, sociocultural factors, comorbid medical conditions, adverse life events, and psychological factors. These factors can result in or compound cognitive-perceptual, emotional and behavioural processes such as alexithymia, catastrophizing interpretations, and avoidant behaviours seen in FSD (Löwe et al., 2024). Based on the theory of constructed emotions, emotions are not fixed but instead constructed based on past experiences and the body’s needs (Jungilligens et al., 2022). FND symptoms can arise from disruptions in the brain’s ability to construct and understand emotions. Based on this concept, the reattribution of bodily symptoms to newly developed, more adaptive emotion concepts can help alleviate FND symptoms (Jungilligens et al., 2022). Dual use of bottom-up (e.g. sensorimotor psychotherapy) and top-down (e.g. cognitive behavioural therapy) approaches may also have complementary therapeutic benefit (Jungilligens et al., 2022; Russell et al., 2022).

Intensive Short-term Dynamic Psychotherapy (ISTDP) is an emotion- and somatically focused variety of brief treatment, which has now been well studied in the assessment and treatment of the spectrum of FSD, including FND (Russell et al., 2022; Abbass et al., 2020, 2021; Abbass et al., 2024). In addition to FSD, the approach has been demonstrated to be effective in mood disorders, anxiety disorders, personality disorders, substance use disorders, and as an adjunct in the treatment of severe mental illnesses (Caldiroli et al., 2020; Abbass et al., 2008b, 2012, 2013).

In this article, we will review the metapsychological theory, assessment tools, treatment processes, and empirical support for ISTDP for functional somatic disorders.

Intensive Short-term Dynamic Psychotherapy

Intensive Short-Term Dynamic Psychotherapy (ISTDP) is a unique form of psychotherapy founded by Dr. Habib Davanloo in the 1960s (Davanloo, 2000; Abbass et al., 2013). It evolved from traditional psychoanalytic principles based on the premise that unprocessed conflicted feelings related to attachment disruptions contribute to psychological symptoms, somatic symptoms and interpersonal problems. Using detailed study of individual cases to observe verbal and nonverbal manifestations of both anxiety and feelings, he developed and taught ways to help people identify and process their actual feelings about the past and the present.

ISTDP metapsychology is based on Davanloo’s observations that interruptions in early attachment bonds in childhood result in painful feelings, secondary rage and guilt about rage. These complex feelings become buried and avoided and instead manifest as specific forms of somatic anxiety and a variety of habitual avoidant behaviours or defences. These feelings and secondary anxiety and defences are activated in current relationships, as feelings are triggered from past relationships (see figure 1). It is typical in this situation that the developing child and later adult are unable to recognize or process emotions - a process called alexithymia - and instead have a variety of somatic symptoms and mental illness manifestations such as anxiety, depression, personality and behavioral dysfunctions (Abbass et al., 2013; Jungilligens et al., 2022).

Figure 1.

Triangle of conflict and Triangle of Person

Through video study of thousands of cases, specific patterns of anxiety are seen in three different channels. In some patients, the unconscious anxiety is channelled into striated muscles, leading to spasms, tremors, tics, and musculoskeletal pain, such as fibromyalgia, tension headaches and other pain conditions. The second anxiety channel is that of smooth muscle, whereby the anxiety can induce bladder spasm, bronchospasm, vascular spasm, and a spectrum of gastrointestinal symptoms. The third channel is when anxiety affects the cognitive-perceptual field, resulting in changes in the sensorium, sensory dysfunction, loss of consciousness, and a variety of other functional neurological symptoms. A fourth related somatic symptom manifestation is when striated muscles become weak, and the person exhibits symptoms of paralysis in any area of the body with striated muscles. This motor conversion process is manifested by a different psychological process whereby emotions are unconsciously repressed and shunted into muscular weakness or some of the other body symptoms such as smooth muscle anxiety or cognitive perceptual disruption (Abbass, 2005; Abbass et al., 2013, 2024). See table 1 and figure 2 for a description of these anxiety channels and clinical manifestations.

Table 1.

Unconscious anxiety channels and manifestations

Anxiety Channel	Clinical Observations on Interview	Clinical Conditions
Striated	Hand clenching, arm tension, neck tension, sighing respirations, tremors, tics, spasms	Fibromyalgia, tension headache, backache, chest pain, shortness of breath, abdominal (wall) pain, tremor, hyperventilation, FND: tremor, spasm, tics
muscle tension
Smooth muscle tension	Relative absence of muscle tension. Instead, activation of smooth muscle causes stomach symptoms, bladder spasm or other symptoms	Irritable bowel syndrome, bladder spasm, bronchospasm, coronary artery spasm, hypertension, migraine
Cognitive- perceptual disruption	Relative absence of striated muscle tension. Losing track of thoughts, blurry vision, loss of hearing, loss of sensation in limbs etc.	Functional Neurological Disorders, Sensory Conversion, Functional Seizures
Conversion	Relative absence of striated muscle tension. Weakness or paralysis in some or all voluntary muscles	Motor Conversion (paralysis or weakness), functional aphonia

Figure 1.

Somatic symptoms disorders affecting various organs

Through an extensive review of recorded video sessions, Dr. Davanloo developed a treatment process to work not only with these anxiety channels but with the variety of defensive habits that preclude healthy engagement in treatment. Specifically, he observed and chronicled multiple types of barriers to treatment. First, the patient may be consciously unwilling to receive treatment for some reason or another. Second, he observed a variety of unconscious barriers to engagement, including barriers against being vulnerable with the therapist, defences against experiencing feelings, and character defences, like habitual defiance, preventing a healthy treatment relationship. Dysregulated anxiety reactions to complex emotions such as smooth muscle anxiety and cognitive-perceptual disruption also interfere with effective and efficient therapy and make emotional awareness and processing very difficult, if not impossible. While all these are obstacles in psychotherapy treatment, they can also impact on physical health assessment and treatment over time (Abbass & Town, 2021).

ISTDP Methods and Mechanism of Action

ISTDP can help address emotion- and behavior-linked factors contributing to the development and continuation of FSD through multiple processes. First, avoidant behavior patterns or defences against engagement and against recognizing and processing feelings can be directly addressed and challenged. Second, helping a person recognize and process underlying emotions can overcome these somatic symptoms. Third, restructuring the anxiety discharge pathways where the anxiety is discharged into smooth muscles or lead to cognitive perceptual disruption can help address certain somatic and neurological symptoms. Finally, the experience of complex emotions will trigger past relevant traumatic memories, which help the patient develop insights into the origins of emotional conflicts and may improve distress, psychological well-being, and interpersonal function (Abbass, 2005; Abbass & Town, 2013; Hoviatdoost et al., 2020).

ISTDP provides a direct method for assessing the somatic discharge pathways of emotions and anxiety, enabling the observation of somatization in chronic conditions (Abbass et al., 2008a). To do this, the therapist initially assesses the patient for the predominant anxiety discharge pathways and typical psychological defences and their capacity to tolerate complex, painful emotions. To assess these patterns, the psychotherapist actively focuses the interview on problematic areas and examples that can shed light on the pathological patterns. The therapist encourages the patient to participate actively in the assessment process. Through this process of psychodiagnosis, the patient and therapist can both see the anxiety manifestations and how they impact somatic symptoms (Abbass, 2005; Abbass et al., 2024).

The ISTDP therapist is very much interested in the somatic experience of specific emotions. For example, the somatic experience of rage is typically a rising energy and heat from the lower part of the body up the chest to the neck and arms with that urge to grab and do some kind of aggression. As opposed to this feeling, grief is an experience of painful feelings with tears, and thoughts about losses. Guilt about rage is experienced with constriction of the muscles of the neck, pharynx and larynx and intense painful feelings with weeping as if one has harmed a loved one. In contrast, positive feelings of love are typically experienced with warmth in the chest and an urge to smile and embrace. In a person who has attachment trauma, typically, these feelings are all fused together in the form of anxiety and somatic symptoms, and the person cannot separate and experience these feelings. Any active situation mobilizing positive feelings, grief, or anger, immediately activates anxiety and defences because of this. In treatment, the therapist helps the patient to identify and separately experience, process, and understand these feelings and to grieve losses that have occurred due to the long-term blockage of emotions (Abbass et al., 2008a, 2013, 2024).

The process of assessing the patient is dependent on their response to focused interviewing, and the anxiety channels that they manifest. If patients respond to focused interviewing by becoming tense in their striated muscles, the therapist encourages them to experience their avoided emotions. Otherwise, if anxiety is going to smooth muscle, cognitive perceptual disruption, or manifest as motor weakness, the therapist needs to first increase anxiety tolerance so they can tolerate the impact of their complex feelings without developing worse somatic symptoms (Abbass, 2005; Davanloo, 1990).

By helping the patient experience their complex feelings in reaction to stressful situations in their current life and within the therapeutic relationship, the patient spontaneously recalls memories associated with the formation of their symptoms and interpersonal problems. For example, the experience of complex feelings of irritation and appreciation towards the therapist become linked to feelings of sadness, rage and guilt related to violent abuse by the father in childhood. This process not only helps the person understand their symptom formation with empathy for themselves and other people, but it also results in immediate or gradual symptom reduction. (Davanloo, 1990; Abbass 2015; Abbass & Town, 2013).

Hence, ISTDP is mostly a bottom-up approach encouraging the patients to focus on the underlying feelings and associated physical experience of these emotions while helping them be aware of their anxiety and defences. A top-down cognitive intervention might first be necessary, in patients who cannot tolerate the anxiety associated with their complex emotions and instead experience smooth muscle anxiety, muscle weakness or cognitive-perceptual disruption. Therefore, this model generally adds to the armamentarium of primarily top-down treatments like cognitive behavioural therapy. This may also explain why there is evidence for better outcomes using ISTDP compared to CBT for the treatment of conditions like chronic pain. (Abbass et al., 2022; Thoma & Abbass, 2022).

Results

Outcome evidence for ISTDP in FSD

ISTDP has been evaluated for its effectiveness in treating various somatic conditions including FND, headaches, chronic pain and other conditions (Abbass et al., 2020, 2021).

Chronic pain

Seventeen studies have examined the effects of ISTDP on pain conditions (table 2). Thirteen of these studies have been randomized controlled trials and four have been case series. ISTDP outperformed other formal treatments in five of these studies and was equal to active treatment controls in two of the studies. In six studies it outperformed non-treatment controls, and in two studies it outperformed treatment as usual controls. A meta-analysis in 2022 found that ISTDP outperformed cognitive behavioural therapy for chronic pain (Abbass et al., 2022). ISTDP reduced symptoms and healthcare costs in four case series (Lilliengren et al., 2020; Hawkins, 2003; Flibotte, 2012; Abbass et al., 2008a). In chronic headache patients, ISTDP reduced healthcare costs and symptoms (Abbass et al., 2008a) and showed greater effects than control in a second study (Shahverdi et al., 2024). ISTDP in group format reduced pain intensity in chronic pain patients, although it did not significantly alter levels of emotional repression (Hawkins, 2003). ISTDP was more effective than Mindfulness-based Stress Reduction (MBSR) and treatment as usual in reducing pain intensity and improving functional recovery in patients with medically unexplained pain (Chavooshi et al., 2016a). In-person ISTDP was more effective than internet-delivered ISTDP for pain reduction and improved mental health outcomes. (Chavooshi et al., 2017b)

Table 2.

Studies of ISTDP for Chronic Pain Presentations

Author	Condition	Treatment	Design	N	Significant Outcomes
Karimi et al. (2023 a, b)	Chronic Pain	ISTDP	RCT	45	ISTDP = MBCT; > control
Krohner et al. (2024)	Chronic Pain	EAET + ISTDP	RCT	91	ISTDP > control
Narimani et al. (2022)	Chronic Pain	ISTDP	RCT	60	ISTDP > Hypnosis
Yarns et al. (2020)	Chronic Pain	EAET + ISTDP	RCT	53	ISTDP > CBT
Chavooshi et al. (2017a)	Chronic Pain	ISTDP	RCT	341	ISTDP = CBT; symptom reduction
Chavooshi et al. (2016a)	Chronic Pain	ISTDP	RCT	63	ISTDP > MBSR and TAU
Chavooshi et al. (2017b)	Chronic Pain	ISTDP	RCT	81	In-person > Internet ISTDP
Chavooshi et al. (2016b)	Chronic Pain	I-ISTDP	RCT	100	ISTDP > TAU
Lilliengren et al. (2020)	Chronic Pain	ISTDP	Case Series	228	Symptom and healthcare cost reduction
Hawkins (2003)	Chronic Pain	ISTDP	Case Series	47	Symptom reduction
Farzadkia et al. (2023 a, b, c)	Fibromyalgia	ISTDP	RCT	36	ISTDP > MBSR and control
Flibotte (2012)	Fibromyalgia	ISTDP	Case Series	67	Symptom reduction
Abbass et al. (2008a)	Chronic Headache	ISTDP	Case Series	29	Symptom and healthcare cost reduction
Chirco & Bargnani (2015)	Bruxism	ISTDP	RCT	41	ISTDP > control
Nakhaei Moghadam et al. (2024)	Chronic Pain	ISTDP	RCT	30	ISTDP > control
Shahverdi et al. (2024)	Tension Headache	ISTDP	RCT	30	ISTDP > control
Yarns et al. (2024)	Chronic Pain	ISTDP/ EAET	RCT	126	ISTDP/EAET>CBT

ISTDP = Intensive Short-Term Dynamic Psychotherapy; EAET = Emotional Awareness and Expression Therapy, I= internet provided ISTDP, MBCT = Mindfulness-based Cognitive Therapy, MBSR = Mindfulness Based Stress Reduction, MUS= Medically Unexplained Symptoms, SSD = Somatic Symptom Disorder, TAU= Treatment as Usual, RCT=Randomized Controlled Trial

Functional neurological disorders

Four case series studies examined the effectiveness of ISTDP in functional neurological disorders (table 3). Two of the studies were of functional seizures (Russell et al., 2016, Malda Castillo et al., 2022, 2023) and both reported symptom reduction as well as cost effectiveness at follow up. A third found gains in symptoms of functional movement disorders in a single blind study (Hinson et al, 2006). The fourth found significant improvements in quality of life and a trend toward significant gains in function in a mixed FND population (Russell et al., 2017).

Table 3.

Studies of ISTDP for functional neurological disorders

Author	Condition	Treatment	Design	N	Outcome
Russell et al. (2017)	Functional Neurological Disorders	ISTDP	Case Series	11	Improvement in quality of life, trend to significant gains in function
Russell et al. (2016)	Functional seizures	ISTDP	Case Series	28	Symptom and healthcare cost reduction
Malda Castillo et al. (2022, 2023)	Functional seizures	ISTDP	Case Series	18	Symptom reduction Healthcare use reduction
Hinson et al. (2006)	Functional movement disorders	ISTDP	Case Series	9	Symptom reduction

Smooth muscle conditions

Three randomized controlled trials, one quasi-experimental trial, and one case series examined the effectiveness of ISTDP in conditions that involve the smooth muscle (table 4). Three of these studies involved patients with irritable bowel syndrome, one included patients with functional gastrointestinal disorders, and one included patients with pelvic pain and urethral syndrome. ISTDP outperformed controls in reducing symptoms in patients who had IBS or other functional GI disorders in the three experimental trials. Hajrezaei et al. (2024) reported ISTDP was effective in pain in patients with urethral syndrome, showing better reducing symptoms and improving depression in three results than traditional urological therapies. It also led patients with IBS. In the Baldoni et al., (1995) study, to improvements in psychological parameters such as ISTDP significantly improved urinary symptoms and depression, anxiety, and hostility.

Table 4.

Studies of ISTDP for Smooth Muscle Conditions

Author	Condition	Treatment	Design	N	Outcome
Jafari (2023)	Irritable Bowel Syndrome	ISTDP	RCT	30	ISTDP > control
Farzdi et al. (2021)	Irritable Bowel Syndrome	ISTDP	RCT	30	ISTDP > control
Baldoni et al. (1995)	Urethral syndrome /Pelvic Pain	ISTDP	RCT	36	ISTDP > treatment as usual
Hajrezaei et al. (2024)	IBS	ISTDP	Case Series	3	Improved GI symptoms and depression
Rostami Ravari et al. (2024)	Functional GI patients	ISTDP	Quasi-experimental	16	ISTDP>Control

RCT=Randomized Controlled Trial

Mixed presentations

Fifteen studies examined the effects of this treatment on other and mixed somatic populations (table 5). Seven of the studies examined mixed somatic symptoms in various settings. In a recent RCT by Town et al. (2024), ISTDP outperformed treatment as usual (TAU) in patients referred from emergency department. Another RCT by Irani et al. (2023) reported ISTDP was more effective than existential therapy and a non-treatment control group in patients with SSD. Four case series showed ISTDP was effective in various settings including family practice, emergency department, community-based and tertiary psychiatric settings. (Cooper et al., 2017; Abbass 2002; Abbass et al., 2009a, 2010, 2015).

Table 5.

Studies of ISTDP for Mixed Presentations

Author	Condition	Treatment	Design	N	Outcome
Town et al. (2024)	SSD	ISTDP	RCT	37	ISTDP>TAU
Irani et al. (2023)	SSD	ISTDP	RCT	45	ISTDP > Existential Therapy and control
Abbass (2015)	MUS tertiary service	ISTDP	Controlled	890	Symptom and healthcare cost reduction
Abbass et al. (2009, 2010)	MUS in Emergency	ISTDP	Controlled	77	Symptom and ED visit reduction
Cooper et al. (2017)	MUS in Family Practice	ISTDP	Case Series	37	Symptom reduction
Abbass (2002)	MUS	ISTDP	Case Series	29	Symptom reduction
Naghibi et al. (2023)	Atopic Dermatitis	ISTDP	Case Series	5	Symptom Reduction
Watt et al. (2019)	IBD	ISTDP	Case Series	7	Symptom reduction
Watt & Abbass (2019)	IBD	ISTDP	Case Series	2	Symptom Reduction
Milo et al. (2024)	IBD	STPP	RCT	60	ISTDP>Control Remission
Yousefi et al. (2024)	Breat Cancer-Self-Compassion and Personality Organization in Breast Cancer	ISTDP	Quasi-experimental	30	ISTDP>control
Jamshidi et al. (2023)	Pain in breast cancer	ISTDP	Case Series	3	Improved pain anxiety and self-empathy
Arabkhazaeli et al. (2024)	Pain in Breast Cancer	ISTDP	Quasi-experimental	30	ISTDP>Control
Moradian et al. (2017)	Treatment-resistant sexual dysfunction in women	ISTDP	Quasi-experimental	5	Improved sexual function
Amani et al. (2020)	Anxiety in Rheumatoid Arthritis	ISTDP	Quasi-experimental	40	ISTDP>Control

MUS= Medically Unexplained Symptoms, RCT=Randomized Controlled Trial

ISTDP has proven effective in improving mental health and reducing symptoms in various medical conditions. Case series of patients with dermatitis (Naghibi et al., 2023) and inflammatory bowel disease (Watt & Abbass, 2019; Watt & Irving, 2019) reported symptom improvement. ISTDP added to standard medical treatment, increased remission rate in adolescents and young adults with inflammatory bowel disease (Milo et al., 2024). Three studies showed ISTDP decreased pain-related anxiety and enhanced self-compassion in women with breast cancer (Yousefi et al., 2024; Jamshidi et al., 2023; Arabkhazaeli & Ghorbanzadeh, 2024). ISTDP was effective for treatment-resistant female sexual dysfunction (Moradian et al., 2017) and decreased anxiety in patients with Rheumatoid Arthritis (Amani et al., 2020).

A recent meta-analysis showed that Short-term Psychodynamic Psychotherapy (STPP) reduced somatic symptoms compared to wait list, minimal treatment, and treatment-as-usual controls for functional somatic disorders and resulted in moderate to large improvements in multiple outcome domains that are sustained in long-term follow-up (Abbass et al., 2020, 2021).

Process Research

Several process and qualitative studies also support ISTDP theory and evidence for its effectiveness. First, a series of studies show that emotional awareness and experiencing result in greater symptom reduction (Town et al., 2013, 2017; Johansson et al., 2014; Hoviatdoost et al., 2020). This finding was noted in the first interview and throughout treatment courses as well (Abbass et al., 2017). One study of patients with somatic symptoms in the emergency department noted that emotional awareness was important in their outcome (Town et al., 2017). Further, one process study found that processing mixed feelings, including anger, is related to outcomes in somatic symptom presentations (Town et al., 2017). Finally, higher levels of alexithymia and emotional avoidance at baseline were related to greater somatic symptom reduction in one recent randomized controlled trial of mixed FSD patients (Town et al, 2024).

Discussion

Somatic symptom disorder is very common and place a massive burden on healthcare providers and the medical system. Hence, novel effective and cost-effective brief treatment options are welcome. There is ample evidence that emotional factors can generate or exacerbate somatic symptoms disorders. ISTDP is an emotion- and somatically-focused therapy which focuses specifically on unprocessed complex emotions related to psychological traumatic experiences. Identifying and managing specific anxiety channels—striated muscle tension, smooth muscle activation, cognitive-perceptual disruption, and striated muscle weakness—are crucial elements of the therapeutic approach. ISTDP offers a dual approach integrating both bottom-up (emotion-focused) and top-down (cognitive-focused) interventions may offer a more comprehensive treatment strategy for patients with complex somatic and emotional presentations.

The evidence from the review of thousands of video-recorded sessions, and research data on ISTDP, including process research, verifies ISTDP as an efficacious intervention model for various somatic and functional symptom disorders. The finding that ISTDP may be more effective than CBT in treating chronic pain suggests that the emotional focus of ISTDP may address aspects of functional somatic disorders that other therapies do not fully reach.

ISTDP’s impact on healthcare utilization and cost is particularly noteworthy. The therapy has been associated with reduced hospitalizations, medication use, and healthcare visits, which indicates its potential as a cost-effective treatment option.

Despite promising results, the small sample sizes of some of the studies and the relative paucity of head-to-head comparisons suggest that further research on ISTDP should be pursued. Process research is also warranted to determine which type of patients preferentially may benefit from this approach versus other modalities.

Conclusions

Somatic Symptom disorders are common health problems which create significant physical distress and anxiety for patients and are costly to the healthcare system. Emotional processing plays a crucial role in successful treatment of these conditions. There is ample evidence to suggest that emotion- and somatically-focused therapies such as ISTDP are effective and efficient psychotherapeutic models to facilitate emotional processing and treat SSDs. This review highlights the importance of integrating emotion-focused psychotherapies into traditional medical treatments to enhance patient outcomes, especially for conditions with a significant psychosomatic component. Further research, including controlled trials for various clinical populations and further process research is needed to confirm these findings and the clinical application of this approach.