Somatic Symptom and Related Disorders Notes
Somatic Symptom and Related Disorders
Everyone experiences somatic symptoms, but some individuals are overwhelmed by them.
These concerns may stem from major medical illnesses or have unclear origins.
Commonality: Pervasive thoughts and behaviors centered on these sensations.
DSM-5 Perspective:
Focuses on thoughts and behaviors related to somatic symptoms.
Older perspectives relied on medically unexplained symptoms, which were unreliable.
Aimed to reduce conflict between doctors and patients.
ICD-10:
Continues the older approach but planned revisions will align with DSM-5.
Clinical Presentation
Patients have one or more somatic symptoms that are all-consuming or impair daily life.
Symptoms are not required to be medically unexplained in DSM-5.
Psychiatrists often treat patients with medically established diagnoses who are disproportionately troubled by physical symptoms.
Somatic Symptom Disorder
Patients believe they have a severe, undetected disease.
Evidence to the contrary does not persuade them.
They may maintain a belief in a particular disease or transfer it to another over time.
Fixation on one or more somatic symptoms as evidence of illness.
Convictions persist despite negative lab results, benign disease course, and reassurances from physicians.
Some may have genuine medical conditions with excessive and unreasonable anxiety.
Patients often experience symptoms of depression and anxiety.
Illness Anxiety Disorder
Similar to somatic symptom disorder: belief in a serious, undiagnosed disease despite contrary evidence.
May maintain or transfer their belief to another disease over time.
Convictions persist despite negative lab results, benign disease course, and reassurances from physicians.
Preoccupation with illness interferes with interactions with family, friends, and coworkers.
Often addicted to internet searches, inferring the worst from found information.
Key Difference: Unlike somatic symptom disorder, these individuals don't have significant physical symptoms.
May develop a fear of medical appointments or seek excessive reassurance from medical providers.
Conversion Disorder (Functional Neurologic Symptom Disorder)
Patients present with what appears to be a neurologic condition.
Symptoms may be motor or sensory but are incompatible with known neurologic conditions.
Often preceded by conflicts or other stressors and associated with apparent psychological factors.
Individuals do not intentionally produce these symptoms or deficits.
Motor symptoms may mimic paralysis, ataxia, dysphagia, or seizure disorder (nonepileptic seizures [NESs]).
Sensory symptoms may mimic neurologic deficits such as blindness, deafness, or anesthesia.
Disturbances of consciousness may occur (e.g., amnesia, fainting spells).
Psychological Factors Affecting Other Medical Conditions
Patients have physical disorders caused by or adversely affected by emotional or psychological factors.
A medical condition must always be present for the diagnosis.
Examples include:
Denial of treatment for an acute condition.
Exacerbation of asthma or irritable bowel attacks by anxiety.
Manipulation of insulin or diuretics to lose weight.
Factitious Disorder
Patients feign, misrepresent, simulate, cause, induce, or aggravate illness to receive medical attention, regardless of whether they are ill.
May inflict painful, deforming, or life-threatening injuries on themselves or others.
Primary motivation is to receive medical care and partake in the medical system, not for concrete gains.
Can lead to significant morbidity or mortality.
Health professionals must take the medical and psychiatric needs of these patients seriously.
Historically called “Munchausen syndrome,” referencing Baron Munchausen.
Other Specified and Unspecified Somatic Symptom and Related Disorders
Patients present with somatic symptoms that do not meet the threshold for another disorder.
Example: Symptoms consistent with illness anxiety disorder, but do not meet the duration criterion (brief illness anxiety disorder).
When there is not enough information for a specific diagnosis, clinicians should use the unspecified somatic symptom and related disorder diagnosis.
Diagnosis
Somatic Symptom Disorder (DSM-5)
One or more somatic complaints that result in significant angst or functional impairment.
Anxiety about their symptoms or preoccupation with them.
Analogous diagnosis in ICD-10 and previous DSM: somatization disorder.
Biggest difference: Whether there needs to be evidence that there is no underlying medical cause.
ICD-10 and DSM-IV required this.
DSM-5 does not require this.
Example: Mr. K
White man in his mid-50s complaining of gastrointestinal problems.
Long list of physical symptoms and concerns related to the gastrointestinal system.
Disturbances from virtually every organ system.
Symptoms started more than 20 years ago.
Evaluated by psychiatrists, general practitioners, and other medical specialists.
Regularly used the internet and traveled extensively in search of expert evaluations.
Underwent repeated colonoscopies, sigmoidoscopies, CT scans, MRI studies, and ultrasound examinations.
Revealed Barrett esophagus but no other pathology.
On disability and unable to work for more than 2 years due to his condition.
Exploratory surgical intervention for intestinal obstruction led to more operations.
Underwent subtotal colectomies and ileostomies due to possible “adhesions.”
Available records did not disclose any specific pathology other than “intractable constipation.”
Pathologic specimens were also inconclusive.
Physical and neurologic examination normal except for multiple abdominal scars and a right ileostomy.
Patient kept pointing to an area of “hardness” in the left lower quadrant.
Primary care physician scheduled brief monthly visits with brief physicals and reassurance.
Referred the patient back to psychiatry.
Psychiatrist confirmed a long list of medically unexplained physical symptoms.
Psychiatric examination revealed some anxiety symptoms and possible symptoms of depression.
Mental status examination showed that Mr. K’s mood was rather somber and pessimistic.
Affect was irritable and he was somatically focused with little psychological insight.
The psychiatrist diagnosed somatic symptom disorder, severe.
Agreed to a few regular visits for assessment and was seen only for “supportive psychotherapy.”
The patient was operated on at least one more time and continued to complain of abdominal bloating and constipation.
Continued to believe he had an obstruction of his intestines and refused pharmacologic treatment.
The only medication he accepted was a low-dose benzodiazepine for anxiety.
Continued to monitor his intestinal function 24 hr/day and seek evaluation by prominent specialists.
Table 12-1 Somatic Symptom Disorder (DSM-5) and Somatization Disorder (ICD-10)
DSM-5 | ICD-10 | |
|---|---|---|
Name | Somatic Symptom Disorder | Somatization Disorder |
Duration | ≥6 mo | ≥2 yr |
Symptoms | ||
# Symptoms needed | ≥1 | |
Exclusion | ||
Psychosocial impact | Distress or impairment | |
Symptom specifiers | With predominant pain | |
Severity specifiers | Mild: 1 symptom | |
Course specifiers | Persistent: >6 mo |
Transient manifestations can occur after significant stresses.
States lasting fewer than 6 months are diagnosed as “Other Specified Somatic Symptom and Related Disorders” in DSM-5.
Transient responses generally remit with resolution of stress but can become chronic if reinforced.
Illness Anxiety Disorder (DSM-5)
Preoccupied with the false belief that they have or will develop a severe disease.
Few if any physical signs or symptoms.
Patients focus on concerns that they will get sick or have an undiagnosed illness.
With somatic symptom disorder, there are significant health concerns along with substantial somatic symptoms.
Analogous disorder in ICD-10 and DSM-IV: hypochondriasis.
Table 12-2 Illness Anxiety Disorder (DSM-5) and Hypochondriasis (ICD-10)
DSM-5 | ICD-10 | |
|---|---|---|
Name | Illness Anxiety Disorder | Hypochondriacal Disorder |
Duration | ≥6 mo | |
Symptoms | ||
# Symptoms needed | All the above | |
Exclusion | Another mental disorder | |
Symptom specifiers | Care-seeking type | |
Care-avoidant type | ||
Comments | Body dysmorphic disorder included as a subtype |
Conversion Disorder (Functional Neurologic Symptom Disorder)
Acute and temporary loss or alteration in motor or sensory function.
Substantial discordance between symptoms displayed and any neurologic condition.
Onset frequently coincides with psychological issues, termed as being “converted” to neurologic symptoms.
Classic syndromes: paralysis, seizures, or blindness.
Table 12-3 Conversion Disorder (Functional Neurologic Symptom Disorder)
DSM-5 | ICD-10 | |
|---|---|---|
Name | Conversion Disorder (Functional Neurologic Symptom Disorder) | Dissociative (Conversion) Disorders |
Symptoms | ≥ Voluntary motor or sensory symptoms | |
Exclusion | Another mental illness | |
Another medical condition | ||
Psychosocial impact | Marked distress and/or functional impairment | |
Symptom specifiers | With weakness or paralysis | Dissociative stupor |
With abnormal movement | Dissociative motor disorder | |
Course specifiers | Acute episode (<6 mo) | |
Persistent (≥6 mo) |
Example: Mr. J
28-year-old single man brought to the emergency department by his father due to loss of vision.
Vision loss occurred while sitting in the back seat on the way home from a family gathering.
Had been playing volleyball, sustaining no significant injury except for the volleyball hitting him in the head a few times.
Vision improved when his father stopped the car and they talked.
History revealed he had been shy as an adolescent, particularly around athletic participation.
Examination findings were routine.
The patient was somewhat perplexed but amenable to discussion focused on the potential role of psychological and social factors in acute vision loss.
Table 12-4 Common Symptoms of Conversion Disorder
Motor Symptoms | Sensory Deficits | Visceral Symptoms |
|---|---|---|
Involuntary movements | Anesthesia, especially extremities | Psychogenic vomiting |
Tics | Midline anesthesia | Pseudocyesis |
Blepharospasm | Blindness | Globus hystericus |
Torticollis | Tunnel vision | Swooning or syncope |
Opisthotonos | Deafness | Urinary retention |
Seizures | Diarrhea | |
Abnormal gait | ||
Falling | ||
Astasia–abasia | ||
Paralysis | ||
Weakness | ||
Aphonia |
Table 12-5 Distinctive Physical Examination Findings in Conversion Disorder
Condition | Test | Conversion Findings |
|---|---|---|
Anesthesia | Map dermatomes | Sensory loss does not conform to recognized pattern of distribution |
Hemianesthesia | Check midline | Strict half-body split |
Astasia–abasia | Walking, dancing | With suggestion, those who cannot walk may still be able to dance; alteration of sensory and motor findings with suggestion |
Paralysis, paresis | Drop paralyzed hand onto face | Hand falls next to face, not on it |
Hoover test | Pressure noted in examiner’s hand under paralyzed leg when attempting straight leg raising | |
Coma | Examiner attempts to open eyes | Resists opening; gaze preference is away from doctor |
Aphonia | Request a cough | Essentially normal coughing sound indicates cords are closing |
Syncope | Head-up tilt test | Magnitude of changes in vital signs and venous pooling do not explain continuing symptoms |
Tunnel vision | Visual fields | Changing pattern on multiple examinations |
Blindness | Swinging flashlight sign (Marcus Gunn) | Absence of relative afferent pupillary defect |
Binocular visual fields | Sufficient vision in “bad eye” precludes plotting normal physiologic blind spot in good eye |
Sensory Symptoms
Anesthesia and paresthesia are common, especially of the extremities.
The distribution of the disturbance is usually inconsistent with either central or peripheral neurologic disease.
Clinicians may see stocking-and-glove anesthesia or hemianesthesia along the midline.
May involve organs of special sense, causing deafness, blindness, and tunnel vision.
Neurologic evaluation reveals intact sensory pathways.
Motor Symptoms
Include abnormal movements, gait disturbance, weakness, and paralysis.
Movements generally worsen when calling attention to them.
Astasia–abasia: wildly ataxic, staggering gait with gross, irregular, jerky truncal movements and thrashing arm movements.
Patients rarely fall and are generally not injured.
Paralysis and paresis involving one, two, or all four limbs, but the muscle distribution does not conform to neural pathways.
Reflexes remain normal and electromyography findings are normal.
Seizure Symptoms
NESs are another symptom of conversion disorder, challenging to differentiate from actual seizures.
Tongue-biting, urinary incontinence, and injuries after falling can occur but are generally not present.
Patients with NESs retain pupillary and gag reflexes and have no postseizure increase in prolactin concentrations.
Other Associated Features
Primary Gain: keeping internal conflicts outside their awareness.
Symptoms have symbolic value, representing an unconscious psychological conflict.
Secondary Gain: tangible advantages and benefits as a result of being sick.Being excused from obligations and difficult life situations and receiving support.
La Belle Indifférence: patient’s inappropriately cavalier attitude toward severe symptoms.Not pathognomonic but often associated with the condition.
Identification: patients may unconsciously model their symptoms on those of someone important to them.
Psychological Factors Affecting Other Medical Conditions (DSM-5)
Individuals have a medical illness that is significantly impacted by psychological influences or patterns of behavior.
Only diagnose when the effect of the psychological issue on the medical condition is unambiguous.
Factors include psychological distress, interpersonal interaction, coping styles, and maladaptive health behaviors.
Psychiatric consequences of having a medical condition are classified as an adjustment disorder.
Example: Mr. A
55-year-old man hospitalized in the intensive care unit following a cardiac arrest.
Experienced severe substernal chest pain but ignored it.
Rejected having had a heart attack and was preparing to leave the unit against medical advice.
History of his father and brother having died of coronary disease.
Irritable and anxious at the initial assessment.
Agreed to stay in the ICU overnight after his wife insisted.
Prescribed a low dose of benzodiazepine and agreed to remain in the hospital for further treatment.
Factitious Disorder
Faking of physical or psychological signs and symptoms.
Symptoms can be imposed on self or imposed on another.
Factitious Disorder Imposed on Self
Feigning a medical or psychiatric illness to achieve the sick role.
May misrepresent symptoms, cause injury to themselves, or use other dishonest methods.
Feigned symptoms frequently include depression, hallucinations, dissociative and conversion symptoms, and bizarre behavior.
Receive large doses of psychoactive drugs and may undergo electroconvulsive therapy.
False history of the recent death of a significant friend or relative.
Memory Loss: Recent and remote memory loss.
Combination of psychoactive substances can produce very unusual presentations.
Other psychological symptoms include pseudologia fantastica and impostorship.
Table 12-6 Factitious Disorder
DSM-5 | ||
|---|---|---|
Name | Factitious Disorder | Intentional Production or Feigning of Symptoms or Disabilities, Either Physical or Psychological (Factitious Disorder) |
Symptoms | Factitious disorder imposed on self: Fabricates their symptoms and clinical findings Claims to be ill Purposely misleads health professionals No apparent external reward or motivation (outside of the illness role) | Feigns symptoms No apparent external reward or motivation Aim is to take on the sick role |
Exclusion | Another mental disorder | Factitious dermatitis |
Malingering | ||
Course specifiers | Single episode | |
Recurrent episodes (2 or more discrete events) | ||
Comments | Note: In factitious disorder imposed on another, the perpetrator receives the diagnosis, not the victim. |
Table 12-7 Clues That Should Trigger Suspicion of Factitious Disorder
The patient has sought treatment at various different hospitals or clinics
The patient is an inconsistent, selective, or misleading informant
The course of the illness is atypical and does not follow the natural history of the presumed disease
A remarkable number of medical treatments have been done to little or no avail
The magnitude of symptoms consistently exceeds objective pathology
Some findings are discovered to have been self-induced or at least worsened through self-manipulation
The patient might eagerly agree to or request invasive medical procedures or surgery
Physical evidence of a factitious cause might be discovered during the course of treatment
The patient predicts deteriorations or there are exacerbations shortly before their scheduled discharge
A diagnosis of factitious disorder has been explicitly considered by at least one healthcare professional
The patient is noncompliant with diagnostic or treatment recommendations or is disruptive on the unit
Evidence from laboratory or other tests disputes information provided by the patient
The patient has a history of work in the healthcare field
The patient engages in gratuitous, self-aggrandizing lying
The patient has been prescribed (or obtained) opiate drugs when not indicated
While seeking medical or surgical intervention, the patient opposes psychiatric assessment
Pseudologia Fantastica
The patient mixes limited factual material with extensive and colorful fantasies.
Imposture is commonly related to lying in these cases.
Imposture
Many patients assume the identity of a prestigious person.
Other Symptoms
Complaints of pain: Contaminating urine with blood or feces.
Patients often insist on surgery and claim adhesions from previous surgical procedures.
Factitious Disorder Imposed on Another (formerly Factitious Disorder by Proxy)
A person intentionally produces physical signs or symptoms in another person who is under the first person’s care.
The most common cause involves a mother who deceives medical personnel into believing that her child is ill.
Example: BC
1-month-old girl admitted for the evaluation of fever.
Inconsistencies in the mother’s reporting: The mother reported having ovarian cancer and hysterectomy however medical records did not validate this.
Medical team discovered that the mother had brought her children to multiple emergency rooms, giving inaccurate histories.
Clinicians suspected that BC’s mother intentionally fabricated symptoms, such as by warming BC’s thermometer.
The team made a referral to social services, and the pediatrician scheduled regular follow-up visits for the children.
Table 12-8 Methods of Factitious Symptom Production, Suggestive Signs, and Confirmatory Tests by Systems
Table 12-9 Clues Triggering Suspicion for Factitious Disorder Imposed on Another Person
Diagnosis does not match the objective findings
Signs or symptoms are bizarre
Caregiver does not express relief when told that dependent is improving or does not have a particular illness
Inconsistent histories of symptoms from different observers
Caregiver insists on invasive procedures or hospitalizations
Caregiver’s behavior does not match expressed distress
Signs and symptoms begin only in the presence of one caregiver
Sibling or another dependent has an unusual or unexplained illness or death
Sensitivity to multiple environmental substances or medicines
Failure of the dependent’s illness to respond to its normal treatments or unusual intolerance to those treatments
Caregiver publicly solicits sympathy or donations because of the dependent’s rare illness
Extensive unusual illness history in the caregiver or caregiver’s family; caregiver’s history of somatization disorders
Caregiver seeks other medical opinions when told the dependent does not have illness
Caregiver perseverates about borderline abnormal results of no clinical relevance
Other Specified or Unspecified Somatic Symptom and Related Disorders
Conditions characterized by one or more unexplained physical symptoms below the threshold for a diagnosis.
Not better explained solely by another medical, psychiatric, or substance use disorder.
Cause clinically significant distress or impairment.
Evaluation of Somatic Symptom and Related Disorders
Patients approach medical encounters with unrealistic expectations, pessimism, and distrust.
Building a trusting alliance must begin with respect for the patient’s symptoms and an acknowledgment of their validity.
Avoid an emphasis on psychological questioning and interpretations at this stage.
A thorough physical examination, including neurologic examination, should follow history-taking at the initial visit.
Differential Diagnosis
Somatic Symptom Disorder
Differentiate from nonpsychiatric medical conditions.
Includes AIDS, endocrinopathies, myasthenia gravis, multiple sclerosis, degenerative diseases of the nervous system, systemic lupus erythematosus, and occult neoplastic disorders.
Distinguished from illness anxiety disorder by the emphasis on fear of having a disease.
Conversion disorder is acute, generally transient, and usually involves a symptom rather than a particular disease.
Somatic symptom disorder can also occur in patients with depressive and anxiety disorders.
Delusional beliefs in schizophrenia are differentiated by their delusional intensity.
Somatic symptom disorder is distinguished from factitious disorder and malingering because patients experience and do not simulate the symptoms they report.
Illness Anxiety Disorder
Differentiated from somatic symptom disorder by the emphasis on fear of having a disease versus concern about many symptoms.
Conversion disorder is differentiated from illness anxiety disorder as well as somatic symptom disorder by the fact that it is acute, generally transient, and usually involves a symptom rather than a particular disease.
Illness anxiety disorder can be differentiated from obsessive-compulsive disorder by the singularity of their beliefs and by the absence of compulsive behavioral traits.
Delusional beliefs can be differentiated from illness anxiety disorder by their delusional intensity and the presence of other psychotic symptoms.
Conversion Disorder (Functional Neurologic Symptom Disorder)
One of the significant problems in diagnosing conversion disorder is the difficulty in definitively ruling out a medical disorder.
A thorough medical and neurologic workup is essential in all cases.
If the suggestion resolves the symptom, such as with hypnosis, or parenteral amobarbital or lorazepam, the symptoms are probably the result of conversion disorder.
Conversion disorder symptoms occur in schizophrenia, depressive disorders, and anxiety disorders.
One differentiating feature is that conversion disorder requires that the presenting symptoms be inconsistent with neurologic conditions, whereas somatic symptom disorder does not require this inconsistency.
In both malingering and factitious disorder, the symptoms are under conscious, voluntary control.
Psychological Factors Affecting Other Medical Conditions
Differential diagnosis can be complicated and should include other somatic symptom disorders, as well as personality disorders.
Factitious Disorder
Any disorder in which physical signs and symptoms are prominent is part of the differential diagnosis, and the physician must explore the possibility of authentic or concomitant physical illness.
Related disorders: Somatic symptom, conversion, Illness anxiety.
Additionally, a history of many surgeries in patients may predispose.
Differentiated from conversion disorder by the voluntary production of symptoms.
Illness anxiety disorder differs from factitious disorder in the lack of voluntary production of symptoms.
Malingering: To differentiate use
Environmental Goal: Malingerers have a manifest, recognizable environmental goal in producing signs and symptoms. It is also more about gaining something from playing the illness card.
Comorbidity
Somatic Symptom Disorder
Co-occurring anxiety disorders and depressive disorders.
It is possible to have a diagnosed medical condition and receive a co-occurring diagnosis of somatic symptom disorder when the individual experiences more considerable distress and anxiety about the illness than would be expected.
Illness Anxiety Disorder
Comorbidity of illness anxiety disorder and both depressive and anxiety disorders, especially generalized anxiety disorder and panic disorder.
Conversion Disorder (Functional Neurologic Symptom Disorder)
Medical and, especially, neurologic disorders frequently occur.
Depressive disorders, anxiety disorders, and somatic symptom disorder often occur alongside conversion disorder.
Personality disorders also frequently accompany conversion disorder.
Psychological Factors Affecting Other Medical Conditions
All individuals with this diagnosis have at least one other medical condition that is comorbid.
Factitious Disorder
Many persons diagnosed with factitious disorder have comorbid psychiatric diagnoses (e.g., mood disorders, personality disorders, or substance-related disorders).
Course and Prognosis
Somatic Symptom Disorder
The course of the disorder is usually episodic.
There may be an apparent association between exacerbations of somatic symptoms and psychosocial stressors.
Good prognosis: high socioeconomic status, treatment-responsive anxiety or depression, sudden onset of symptoms.
Illness Anxiety Disorder
The course is episodic
Good prognosis: high socioeconomic status, treatment-responsive anxiety or depression, sudden onset of symptoms.
Conversion Disorder (Functional Neurologic Symptom Disorder)
Symptoms or deficits are usually of short duration.
Recurrence occurs in one-fifth to one-fourth of people within 1 year of the first episode.
Good prognostic indicators include acute onset, presence of clearly identifiable stressors, short interval between onset and treatment.
Factitious Disorder
Follows a long pattern of successive hospitalizations.
Factitious disorders are incapacitating to the patient.
The prognosis, in most cases, is poor.
Treatment of Somatic Symptom and Related Disorders
Treatment Approach
Good efficacy of psychotherapy, particularly of the cognitive-behavioral therapy (CBT) type
Antidepressants seem to work in painful syndromes.
Somatic Symptom Disorder
Therapeutic goals should be modest at first.
Recommendations for exercise, yoga, relaxation, meditation, and massage may be useful.
CBT interventions appear to help patients by modifying thoughts and behaviors associated with somatization.
Illness Anxiety Disorder
Various group and individual therapies, including CBT and psychodynamic therapy, have been proposed.
CBT is the prototype, first-line treatment for illness anxiety disorder. limited data exists for pharmacological treatment.
Conversion Disorder (Functional Neurologic Symptom Disorder)
Many conversion syndromes have an acute, benign course and may remit spontaneously with understanding and support.
Reassuring patients that critical tests are normal and that symptoms will eventually improve may be helpful. Psychological interpretations or explanations do not work well early in the process.
Behavioral interventions should focus on improving self-esteem, the capacity for emotional expression and assertiveness, and the ability to communicate comfortably with others.
Factitious Disorder
Treatment, therefore, is best focused on management rather than on cure. There are limited options for therapeutic measures.
The three primary goals in the treatment and management of factitious disorders are (1) to reduce the risk of morbidity and mortality, (2) to address the underlying emotional needs, and (3) to be mindful of legal and ethical issues.
Table 12-10 Guidelines for Management and Treatment of Factitious Disorder
Keep in mind that active pursuit of a prompt diagnosis can minimize the risk of morbidity and mortality.
Treat according to clinical judgment, keeping in mind that subjective complaints may be deceptive.
Appoint a primary care provider as a gatekeeper for all medical and psychiatric treatment.
In psychotherapy, address coping strategies and emotional conflicts.
Avoid aggressive direct confrontation.
Table 12-11 Pediatric Factitious Disorder Imposed on Another—Basic Principles of Management
Personal Reactions of Physicians and Staff Members
May evoke feelings of futility, bewilderment, betrayal, hostility, and even contempt.
One appropriate psychiatric intervention is to suggest to the staff ways of remaining aware that even though the patient’s illness is factitious, the patient is ill.
Epidemiology
Somatic Symptom Disorder
The prevalence of somatic symptom disorder is not yet known.
Illness Anxiety Disorder
The prevalence of this disorder is unknown.
Conversion Disorder (Functional Neurologic Symptom Disorder)
Estimates vary broadly: Less than 1 percent in the general population.
The disorder appears to be more frequent in females and can occur in children as young as 7 or 8 years old.
Factitious Disorder
No comprehensive epidemiologic data on factitious disorder exist.
However, it is estimated to comprise approximately 1 percent of the healthcare-seeking population.
Etiology
Somatic Symptom Disorder
Some have postulated that persons with this disorder augment and amplify their somatic sensations.
Others have proposed a social learning model with a request for admission to the sick role.
Illness Anxiety Disorder
The etiology is unknown.
The social learning model described for somatic symptom disorder may apply to this disorder as well.
Conversion Disorder (Functional Neurologic Symptom Disorder)
Biologic Factors: An inherent deficit in certain brain functions, especially those in the dominant hemisphere and functional MRI.
Psychological Factors: behavioral theory, psychoanalytic theory, childhood traumatization by sexual or physical abuse.
Factitious Disorder
Etiology is generally not clear, except that a common denominator is that these patients tend to be avid medical service seekers.
An affinity for the medical system
Maladaptive coping skills