# Psychosomatic Medicine: Somatic Symptom and Related Disorders

## Introduction

Psychosomatic medicine, now formally recognized as **consultation-liaison (C-L) psychiatry**, addresses the interface between psychiatric illness and medical disease. The DSM-5 restructured the former somatoform disorders into **somatic symptom and related disorders**, shifting the diagnostic emphasis from the absence of medical explanation to the presence of excessive thoughts, feelings, and behaviors related to somatic symptoms.

## Historical Context

The term **psychosomatic** originated from the recognition that psychological factors influence physical disease. Franz Alexander's "Holy Seven" psychosomatic illnesses (peptic ulcer, asthma, rheumatoid arthritis, etc.) represented early attempts to link specific conflicts to specific diseases. Modern C-L psychiatry has moved beyond simplistic mind-body dualism toward an **integrated biopsychosocial model**.

## DSM-5 Classification

| Disorder | Core Feature | Somatic Symptoms | Key Distinguishing Characteristic |
|----------|-------------|-----------------|----------------------------------|
| Somatic Symptom Disorder | Excessive thoughts/feelings/behaviors about somatic symptoms | Present and distressing | Disproportionate response to symptoms (which may or may not be medically explained) |
| Illness Anxiety Disorder | Preoccupation with having a serious illness | Absent or mild | High health anxiety without significant somatic symptoms |
| Conversion Disorder (FNSD) | Altered voluntary motor or sensory function | Neurological symptoms | Positive signs of incompatibility with recognized neurological disease |
| Factitious Disorder | Falsification or induction of illness | Self-induced or fabricated | Absence of obvious external rewards; deception is present |
| Psychological Factors Affecting Other Medical Conditions | Psychological factors worsening a medical condition | Related to a documented medical condition | A genuine medical condition is present and adversely affected |

### Somatic Symptom Disorder (SSD)

One or more somatic symptoms that are distressing or result in significant disruption of daily life. **Excessive thoughts, feelings, or behaviors** related to the somatic symptoms (disproportionate health anxiety, excessive time and energy devoted to symptoms) The symptoms are persistent (typically more than 6 months) A concurrent medical condition does not exclude the diagnosis. Specifiers: with predominant pain; persistent; mild, moderate, or severe.

### Illness Anxiety Disorder

Preoccupation with having or acquiring a serious illness. Somatic symptoms are **absent or mild**. High level of anxiety about health; the patient performs excessive health-related behaviors or exhibits maladaptive avoidance. Subtypes: **care-seeking** vs. **care-avoidant**.

### Conversion Disorder (Functional Neurological Symptom Disorder)

One or more symptoms of altered voluntary motor or sensory function. Clinical findings provide evidence of **incompatibility** between the symptom and recognized neurological or medical conditions. Positive neurological signs (e.g., **Hoover sign**, tremor entrainment) are essential for diagnosis. The symptom is not better explained by another medical or mental disorder.

![Illustration of common positive neurological signs used in the diagnosis of conversion disorder including Hoover sign and drift without pronation](/images/psychiatry/conversion-disorder-signs.png)

### Factitious Disorder

Falsification of medical or psychological signs and symptoms, or induction of injury or disease. The individual presents themselves as ill, impaired, or injured (or presents another person this way in **factitious disorder imposed on another**, formerly Munchausen by proxy) The behavior is evident even in the absence of obvious external rewards. Distinguished from **malingering**, which involves external incentives.

### Psychological Factors Affecting Other Medical Conditions

One or more clinically significant psychological or behavioral factors that adversely affect a medical condition. Examples: non-adherence due to denial of a cancer diagnosis, stress-induced exacerbation of coronary artery disease.

## Epidemiology

SSD affects an estimated **5-7%** of the general population. Higher prevalence in women, older adults, individuals with lower education and socioeconomic status. Conversion disorder has a prevalence of **4-12 per 100,000**; more common in women and in rural settings. Patients with somatic symptom disorders account for disproportionate healthcare utilization.

## Etiology and Pathophysiology

**Neurobiological models**: altered interoception, heightened central sensitization, dysregulated autonomic and HPA axis function. **Psychological factors**: early adverse experiences, insecure attachment, alexithymia, catastrophizing. **Social factors**: illness behavior reinforced by secondary gain, cultural idioms of distress. Neuroimaging in conversion disorder shows altered connectivity between prefrontal cortex and motor/sensory areas.

![Diagram showing the biopsychosocial model of somatic symptom formation with neurobiological, psychological, and social contributing factors](/images/psychiatry/somatic-symptom-biopsychosocial.png)

## Clinical Assessment

Conduct a thorough medical evaluation; do not diagnose by exclusion alone. Use validated screening tools: **Patient Health Questionnaire-15 (PHQ-15)**, **Somatic Symptom Disorder-B Criteria Scale (SSD-12)**. Assess for comorbid depression, anxiety, and trauma history. Evaluate the patient's illness beliefs, attributions, and coping style. Avoid conveying that symptoms are "all in your head".

## Treatment Approaches

### Psychotherapy

**Cognitive-behavioral therapy (CBT)** is the best-studied intervention; targets catastrophizing, body scanning, avoidance behaviors. **Acceptance and commitment therapy (ACT)** helps patients engage in valued activities despite symptoms. **Psychodynamic psychotherapy** addresses unconscious conflicts and alexithymia. Graded exercise and behavioral activation for deconditioning.

### Pharmacotherapy

Antidepressants (SSRIs, SNRIs) for comorbid depression and anxiety. **Duloxetine** and **amitriptyline** have evidence for pain-predominant presentations. Avoid benzodiazepines and opioids. Pharmacotherapy alone is generally insufficient without psychotherapy.

### Collaborative Care

Designate a single primary care physician as the coordinator of care. Schedule regular, brief, time-contingent (not symptom-contingent) appointments. Gradually shift the focus from symptom cure to functional improvement. Limit unnecessary investigations and specialist referrals.

![Infographic depicting the collaborative care model for managing patients with somatic symptom disorders](/images/psychiatry/somatic-collaborative-care.png)

## Key Clinical Pearls

The DSM-5 approach emphasizes positive psychological criteria rather than the absence of medical findings; a medically explained symptom can still warrant a somatic symptom disorder diagnosis if the response is excessive. Conversion disorder should be diagnosed based on positive neurological signs of incompatibility, not merely a negative workup. The therapeutic alliance is the single most important factor in the successful management of somatic symptom disorders. Avoid the false dichotomy of "organic vs. functional"; most presentations involve interacting biological and psychological factors.

## References

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2. Henningsen P, Zipfel S, Sattel H, Creed F. Management of functional somatic syndromes and bodily distress. *Psychother Psychosom*. 2018;87(1):12-31.
3. Stone J, Carson A, Hallett M. Explanation as treatment for functional neurological disorders. *Handb Clin Neurol*. 2016;139:543-553.
4. Kroenke K. Efficacy of treatment for somatoform disorders: a review of randomized controlled trials. *Psychosom Med*. 2007;69(9):881-888.