The major categories of axis I disorders covered in this chapter
are delirium, dementia, amnestic disorders, mental disorders due to
a general medical condition, substance-related disorders, schizophrenia and
other psychotic illnesses, and mood, anxiety, somatoform, dissociative,
factitious, malingering, eating, and sleeping disorders. Figure 284-2 categorizes these disorders
into primarily psychiatric conditions and psychiatric disorders
due to medical conditions.
Amnestic Disorders, and Other Cognitive Disorders
The group of syndromes that includes dementia,
delirium, amnestic disorders, and other cognitive disorders is characterized
by a clinically significant deficit in cognitive or memory function
due to a general medical condition. There are several distinct and
common variants of such syndromes in which the causative factor
is known, for example, vascular dementia and alcohol withdrawal
delirium. In these cases, the specific diagnosis is listed in DSM-IV-TR.
In other cases, the etiologic factor should be specified using the
descriptor “due to [general medical disorder or
substance],” for example, “delirium due
to hepatic encephalopathy.”
Dementia is a pervasive
disturbance of cognitive functioning in several areas, including
memory, abstract thinking, judgment, personality, and other higher
cortical functions such as language. If clouding of consciousness
is present, then the patient does not have solely a dementing illness
but has delirium or intoxication. The presence
of global cognitive impairment may be detected through the use of
a bedside cognitive examination, such as the Mini-Mental State
Examination (see Table 283-5) or the Brief
Mental Status Examination. Additional confirmatory history
should be gathered from an informant, such as a family member. Memory
disturbance is usually the earliest sign to be apparent to others,
and unless it is very mild, it may be easily identified by examination.
Such an examination asks the patient to retain, recall, and register information
such as a list of words. The examiner may ask the patient to remember
three words (tree, pen, and book)
and repeat them back immediately and in 5 minutes.
The incidence of dementia in the community is thought to be 3%,
with 1.8% of cases being undiagnosed. The primary causes
of dementia are Alzheimer disease and multiple cerebral infarctions
(vascular dementia). Other causes include cerebrovascular diseases
such as stroke, infectious disease such as acquired immunodeficiency
syndrome and Creutzfeldt-Jakob disease, traumatic causes such as
anoxia and diffuse axonal injury, toxins such as in chronic substance
abuse, carbon monoxide and heavy metal exposure, autoimmune disorders
such as systemic lupus erythematosus and sarcoidosis, and avitaminoses.
The diagnosis of dementia is challenging in patients with coexistent
schizophrenia and in elderly patients with dementia that is secondary
to major depression.
Patients with dementia may be brought to the
ED after having been found wandering away from home, a nursing home,
or other institution. Because the onset of most forms of dementia
is slow and gradual, such patients often present to the ED only
when some acute worsening of mental status occurs, which may be
the result of a superimposed medical illness, adverse drug effect,
or environmental change. Demented patients’ diminished
intellectual and physiologic resources allow abrupt worsening of
function with the addition of such stressors.
Early in the course of dementia, anxiety, depression,
or psychosis may dominate the clinical picture and obscure cognitive
dysfunction. For this reason, a high degree of clinical suspicion
of dementia should be maintained when evaluating an elderly patient
with no prior psychiatric history who presents with new psychiatric
problems. New onset of dementia warrants a proper medical
evaluation for possible causes. Demented persons are also prone
to unrecognized physical illness, because of their inability to
perceive or describe symptoms. Careful examination and appropriate
laboratory testing are indicated in the initial and, at times, ongoing
evaluation of such patients.
Proper evaluation and testing may provide evidence of reversible
and treatable causes of dementia. Common causes of potentially reversible dementia
include metabolic and endocrine disorders, polypharmacy, and depression.
Often, especially in elderly patients, depression may present with
prominent cognitive impairment, a condition erroneously labeled “pseudodementia” but
more accurately called dementia of depression.
A relatively acute onset, prominent mood changes, and vegetative
disturbances such as loss of appetite and weight, sleep disturbance, or
expressions of guilt or suicidal ideation point to depression as
the cause. In these situations, treatment of the mood disorder may
lead to resolution of the cognitive impairment, although recent
studies indicate that many such patients have evidence of brain
dysfunction and show only partial response to treatment.
Delirium is characterized by
global impairment in cognitive function but is distinguished from
dementia in two major ways. In delirium, the patient has clouding
of consciousness, a reduction in the awareness of the external environment
(manifest as difficulty sustaining attention), varying degrees of
alertness ranging from drowsiness to stupor, and sensory misperception. In
most patients an underlying general medical condition, substance
intoxication, or withdrawal or medication use is the cause of the
delirium. Delirium must be distinguished from psychiatric illnesses
such as psychotic, mood, anxiety, and stress disorders. There is
a long list of causes of delirium, including intoxicants, withdrawal syndromes,
infections, trauma, seizures, endocrinopathies, inflammatory processes,
shock, organ failure, and neoplasia. The cause of the patient’s delirium
needs to be investigated.
The incidence varies by age and medical condition
from 0.4% in adults in general to 1.1.% in those
≥55 years of age. Hospitalized and nursing home patients and patients
with acquired immunodeficiency syndrome and cancer have an incidence
of up to 60%. Up to 10% of the elderly population
in the ED were found to have delirium, and many of these cases were
unrecognized.3 Compared with adults, children are
more susceptible to delirium brought on by fever and reaction to
The primary distinguishing feature of delirium is a typical acute
course, with rapid deterioration in hours or days, rather than in
months as with dementia. Also, the severity of delirium fluctuates
over the course of hours; the patient may appear normal at one time
and wildly agitated a few hours later. Extreme changes in psychomotor
activity, ranging from restlessness and hyperactivity to stupor,
are frequent in delirium but uncommon in dementia except in the
later stages when a delirious state may be superimposed. Hallucinations,
often visual, are common in delirium.
Amnestic patients typically are unable to learn new information
or to recall information that is already learned. Amnestic
disorders cause a problem in carrying out social and occupational functions
and are not part of delirium or dementia. These patients typically
have evidence of a general medical condition based on their history, physical
examination, and laboratory testing. Causes of amnestic disorder
include brain trauma, stroke, carbon monoxide poisoning, substance abuse,
and chronic nutritional deficiency. Acute onset of amnesia needs to
Due to a General Medical Condition
The DSM-IV-TR has implemented
a major change in the classification of psychiatric symptoms caused
by medical conditions. The previous terminology of “organic
brain syndrome” and the subtypes of “organic mood
disorder” and “organic delusional disorder,” for
example, have been eliminated, because of the implication that the “functional” mental disorders
are unrelated to biologic changes in brain function. Although the
terminology of organic versus functional disorders has been eliminated, DSM-IV-TR includes
primary psychiatric conditions and mental conditions that are due
to medical illness or are substance induced (Figure
284-2). When there is evidence that a psychiatric disturbance
is a direct physiologic consequence of a general medical condition
or substance, the mental disorder is specified as “due
to” the medical problem, for example, “major depression
due to hypothyroidism.” This mental condition cannot be
caused by another mental disorder, and it cannot be part of the
course of delirium.
The diagnostic features of mental disorders due to a general
medical condition rely on evidence from patient history, physical
examination, and laboratory results indicative of a causative medical
condition. Sometimes the cause cannot be determined in the ED, and
the patient may need admission for further evaluation. General medical
conditions may cause amnestic, psychotic, mood, and anxiety disorders.
Substance-related disorders are due to ingestion of a drug of
abuse or alcohol, side effects of a prescribed or over-the counter
medication, or toxic exposure. Substance-related disorders are divided
into substance use disorders and substance-induced disorders. Substance
use disorders include dependence and abuse. Substance-induced disorders
include substance intoxication and withdrawal as well as substance-induced dementia and
amnestic, psychotic, mood, anxiety, sexual dysfunction, and sleep disorders.
The incidence of substance use disorder in ED patients is estimated
to be up to 27%.4 Many ED patients have
undiagnosed or unrecognized substance-related disorders, especially
substance dependence. Screening tools have been used to identify
these persons in the ED. Initiating intervention for the problem
of substance abuse in the ED can be beneficial.5
When recent ingestion of a specific exogenous
substance produces maladaptive behavior and impairment of judgment,
perception, attention, emotional control, or psychomotor activity,
and the patient does not display features of delirium, dementia,
or hallucinosis, a diagnosis of intoxication is
made. When the offending substance is known, it should be specified
(e.g., alcohol intoxication or amphetamine intoxication). The specific
features of intoxication syndromes commonly seen in the ED are described
in greater detail in Section 15, Toxicology.
As a general rule, the diagnosis of intoxication can be made
rather easily when history and physical examination reveal classic
signs and symptoms of an intoxicant or toxidrome. The clinical features
of alcohol intoxication are familiar to experienced emergency physicians
and range from impaired judgment and coordination through ataxia,
lethargy, and coma. When repeated episodes of intoxication occur
within a brief period, the individual by definition has a substance
abuse disorder, and the additional diagnosis is made. A urine toxicology
screening test and measurement of blood alcohol level, or serum
determinations of other intoxicants, are most useful in evaluating
patients with new-onset psychiatric symptoms or altered mental status
without known cause. Such studies are often requested as part of
the assessment of patients transferred to psychiatric facilities.
Withdrawal can follow cessation
or reduction in use of a substance of abuse. The category signifies
a syndrome characteristic of withdrawal from that particular drug,
when the clinical syndrome does not satisfy the criteria for delirium
or dementia. For example, mild forms of alcohol withdrawal would
be classified here, but if the patient is confused, hallucinating,
and agitated, a diagnosis of alcohol withdrawal delirium (delirium
tremens) is indicated. The diagnosis is made based on identification
of the withdrawal syndrome and evidence of recent use of the substance
in a pattern sufficient to produce withdrawal when the amount ingested
is decreased or stopped. Specific withdrawal patterns depend on
Alcohol withdrawal, for instance, includes up
to four stages: autonomic hyperactivity (sweating, tachycardia;
6 to 8 hours after cessation of drinking), hallucinations (24 hours
after withdrawal), major motor seizures (1 to 2 days after cessation),
and global confusion (3 to 5 days after last use of alcohol). Some
withdrawal syndromes, particularly those involving alcohol or barbiturates,
can be life-threatening.
Other Psychotic Disorders
Schizophrenia and related disorders are marked
by the presence of psychotic symptoms, primarily delusions and hallucinations. Delusions are defined
as fixed false beliefs that are not amenable to arguments or facts to
the contrary and that are not shared by others of similar cultural
background. Common delusions are of several types. Persecutory
delusions are those in which one believes that one is being
attacked, followed, harassed, or conspired against. Grandiose
delusions are those that involve themes of special powers
or abilities. Bizarre delusions are those with
patently absurd content, such as believing that one’s thoughts
are controlled by extraterrestrial beings. Hallucinations are
false perceptions experienced in a sensory modality and occurring
in clear consciousness. Auditory hallucinations are the most common,
followed in order of prevalence by nonauditory hallucinations such
as visual, tactile, olfactory, and gustatory. The presence
of nonauditory hallucinations suggests a medical, not psychiatric,
cause of psychosis (such as alcohol withdrawal). The most
prevalent psychosis is schizophrenia, described
in detail in the next section. The other psychotic disorders, discussed
briefly, are less common. A decision tree helpful in evaluating
psychotic symptoms and determining the diagnosis is presented in Figure 284-1.
Schizophrenia is one of the most serious public
health problems in the world, affecting just under 1% of
the world’s population. The essential features are a deterioration
in functioning, characteristic positive symptoms (hallucinations,
delusions, disorganized speech, disorganized behavior, and catatonic
behavior), negative symptoms (blunted affect, emotional
withdrawal, lack of spontaneity, anhedonia, and attentional impairment),
cognitive impairment manifested by loose associations or incoherence
for at least 1 month, and the relative absence of a mood disorder.
Schizophrenia is most likely a group of disorders with different
causes that share a final common pathway. It is a brain disease,
and there is no evidence that psychosocial stressors or poor parenting
is responsible for causing the illness, although these may have
a profound effect on the patient’s adaptation to this usually
Symptoms of schizophrenia usually begin in late
adolescence or early adulthood, although the onset can occur at
any age. The childhood history of schizophrenics often is marked
by shyness, oddness or eccentric behavior, school difficulties,
or paranoid behaviors, but such features are not always present.
A prodromal phase, in which a gradual deterioration of function
is noted, usually precedes the development of active delusions or
hallucinations. Such deterioration usually includes the worsening
of social withdrawal or the new onset of social withdrawal, odd behavior
or speech, and difficulty in functioning at school or work. Patients
or their families rarely seek care until the onset of the active
phase of psychosis. Schizophrenic individuals seldom seek care at
all, because they lack insight; they do not realize that their perceptions,
thoughts, and behavior are abnormal.
Typical, or older, antipsychotic drugs (such
as haloperidol) usually reduce the severity of positive symptoms
(delusions and hallucinations). Other manifestations of schizophrenia
less responsive to typical antipsychotics include negative symptoms
(lack of volition, blunting of emotion, anhedonia, and inattention).
Such symptoms result in lasting impairment in self-care, work, and
social relations. Newer, “atypical,” antipsychotic
agents (such as aripiprazole, quetiapine, risperidone, olanzapine,
clozapine, and ziprasidone) seem to have a greater effect in improving
the negative and positive symptoms. Other advantages of the atypical
agents include better side effect profile, improved cognition, and less
risk of tardivedyskinesia.
Disorganization of thinking and behavior characterizes
schizophrenia. Disheveled appearance and poor grooming, bizarre
behavior, poor judgment, and loosening of associations indicate
such disorganization. Loose associations refer
to a loss of the normal logical connections between one thought
and the next; the schizophrenic patient’s speech is often
vague, rambling, disjointed, or nonsensical.
Common reasons for persons with schizophrenia to come to the
ED include worsening of psychosis resulting from stress or nonadherence
to the medication regimen, suicidal behavior, violence (often as
a result of paranoid thinking), and extrapyramidal side effects
of neuroleptic drugs. Schizophrenics may be brought in by the authorities
in a confused state, obviously unable to attend to their basic needs. Their
poor judgment and disorganization may lead to disregard for medical
problems, so attention must be given to their physical status as
well as to the psychiatric problem.
Schizophreniform disorder is
diagnosed when the patient meets the criteria for schizophrenia
but the symptoms have been continuously present for <6 months.
A rapid onset over a few days and good premorbid functioning are
more common than in schizophrenia.
Some individuals may become acutely psychotic after exposure
to an extremely traumatic life experience. If such a psychosis lasts
for <4 weeks, it is termed a brief psychotic disorder.
Precipitants include the death of a loved one or a life-threatening
situation such as combat or a natural disaster. Emotional turmoil,
confusion, and extremely bizarre behavior and speech are common
in this disorder.
The mood disorders are the most prevalent of
the major psychiatric disorders, affecting about 10% to
15% of the general population at some time in their lives.
Depressive disorders are the major cause of completed suicide. An
unsuccessful attempt may bring the patient to the ED.
Mood, or affective, disorders differ from the
normal extremes of sadness and happiness in that characteristic
clusters of psychological and vegetative symptoms (depressive or
manic syndrome) are present, and functioning is impaired. Any of
the features of schizophrenia such as delusions, hallucinations,
or disorganization may be present, but if a full depressive or manic
syndrome exists, the diagnosis is likely psychotic mood disorder.
Another important characteristic of affective disorders is that
they tend to be episodic, with periods of remission and normal function.
The essential features of major depression are
a persistent sad or depressed (dysphoric) mood or pervasive loss
of interest in usual activities lasting for at least 2 weeks. Associated
psychological symptoms include guilt over past deeds, self-reproach,
feelings of worthlessness or hopelessness, inability to experience
pleasure, and recurrent thought of death or suicide. Vegetative
symptoms involve physiologic functioning and include loss of appetite
and weight, sleep disturbance, fatigue, inability to concentrate,
and psychomotor agitation or retardation. The depression may begin
gradually or rapidly but usually will have been present for several
weeks before the patient comes for treatment.
When the patient complains of the full spectrum of depressive
symptoms, the diagnosis of major depression is easy to make, but
when the chief complaint is a single symptom, such as insomnia or
fatigue, it is necessary to elicit the other symptoms of major depression
to make the diagnosis. Somatic complaints, such as vague pain or
weakness, may be part of major depression, as may generalized anxiety.
A useful screening mnemonic is presented in Table
Table 284-2 In SAD CAGES:
A Screening Mnemonic for Major Depression |Favorite Table|Download (.pdf)
Table 284-2 In SAD CAGES:
A Screening Mnemonic for Major Depression
Major depression is more common in women, persons with a family
history of depression or suicide, and individuals with medical or
other psychiatric illnesses. When a medical disorder or drug produces
a depressive syndrome through a presumed biologic effect on the
brain, the diagnosis should be “depression due to [the
offending condition].” Major depression is often
superimposed on other mental disorders, such as substance abuse,
personality disorders, and anxiety disorders, and such conditions
are frequently comorbid conditions.
Primary mood disorders tend to display more biologic
features, are more familial, and respond better to antidepressant
treatment than do mood disorders due to medical conditions. The
lifetime risk of suicide in patients with major depression is 15%,
so prompt and aggressive treatment is strongly indicated. Major
depression is often recurrent, so certain patients must be maintained
on long-term treatment to prevent relapse.
Bipolar disorder, previously termed manic-depressive illness,
is characterized by the occurrence of mania cycling with periods of
depression. A full manic syndrome is one of the most striking and
distinctive conditions in clinical practice. The essential disturbance
in mood is one of elation or irritability. Manic patients feel “on
top of the world,” expansive, and energetic. The state
is precarious, however, and patients may quickly become argumentative,
hostile, irritable, and sarcastic, especially when their plans are
thwarted. Bipolar disorders are classified into types I and II based
on the presence of mania, which is found in bipolar I disorder and
not found in bipolar II.
The vegetative signs of mania are a decreased
need for sleep, increased activity, rapid and pressured speech,
and racing thoughts. Manics may have grandiose ideas, such as unrealistic
plans to start a business or run for public office, and if the grandiosity
reaches delusional proportions, such patients may believe themselves
to be famous, fabulously wealthy, or blessed with special powers
and abilities. Poor judgment in spending money and sexual behavior
may lead to problems that prompt the families of manic individuals
to seek treatment for them, because manics usually lack insight
into their abnormal condition and deny that anything is wrong. For
this reason, reports from informants such as relatives often reveal
important information to substantiate the diagnosis. Because patients
who have had a manic episode almost invariably have depression at
some time (the other “pole” of bipolar disorder),
a history of depression also may help in diagnosis.
The disorder is equally common in men and women, and the onset
is usually in the third and fourth decades. Complications include suicide, substance
abuse (excessive alcohol use is common during the manic phase),
and marital and occupational disruptions. The course of bipolar
disorder is episodic, with the duration, frequency, and regularity
of the episodes varying greatly. Depressive episodes are more frequent
than manic episodes.
Dysthymic disorder is a more
chronic and less severe form of depressive illness and was previously
termed depressive neurosis. Depressed mood must
have been present most of the day, more days than not, for at least
2 years. Psychotic features are not seen, and patients with this
disorder often have a lifelong gloomy, pessimistic outlook. Women
are affected more often than men, and the onset is typically in
childhood, adolescence, or early adulthood.
Associated personality disorders and substance abuse are common. When
vegetative symptoms are present, they are usually less severe than in
major depression. Major depression may be superimposed on dysthymia,
often in association with stressful life events. When major depression
complicates dysthymia, the patient may be brought in for evaluation
because of the severity of symptoms or for treatment after a suicide
The anxiety disorders are mental
disorders in which apprehension, fears, and excessive worry dominate
the psychological life of the individual. Pathologic degrees of
anxiety are accompanied by different degrees of autonomic activity
(sweating, tachycardia, or dizziness) out of proportion to any real
danger or threat. Because anxiety is a ubiquitous condition and frequently
associated with medical illness, depression, neurologic syndromes,
and psychoses, a diagnosis of a primary anxiety disorder should be
made by exclusion of other causes.
Anxiety disorders are diagnosed in 4% to 8% of
the general population and are diagnosed more often in women than
in men. Because of the physical nature of certain symptoms associated
with anxiety disorders, patients often seek treatment and evaluation
in medical rather than psychiatric settings.
Patients who experience recurrent attacks of
severe anxiety are said to suffer from panic disorder.
For detailed discussion, see Chapter 287, Panic Disorder. A panic attack consists of a sudden extreme surge
of anxiety and dread accompanied by autonomic signs, including palpitations,
tachycardia, shortness of breath, chest tightness, dizziness, sweating,
and tremulousness. The symptoms develop over a few minutes at most
and may be unprovoked or stimulus related, such as
occurring in a crowded store. After the attacks begin, some patients
start to avoid situations that seem to precipitate the panic (phobic
avoidance). When activities are severely limited, the complication
of agoraphobia is diagnosed. In agoraphobia, the
patient tends to avoid situations in which ready escape or assistance
during an attack is not possible. The frequency and severity of
panic attacks wax and wane, but the illness is generally chronic.
When anxiety attacks are absent but the patient
complains of persistent worry, tension, or free-floating anxiety,
a diagnosis of generalized anxiety disorder should be considered.
This condition lasts at least 6 months and is characterized by apprehensive worrying,
muscle tension, insomnia, irritability, restlessness, jumpiness, or
distractibility. Muscle tension may be so severe that the patient
actually experiences diffuse muscular pain. Associated autonomic
symptoms include the cardiopulmonary, GI, and neurologic symptoms
that are seen in panic attacks. In generalized anxiety disorder,
such symptoms occur more continuously and chronically than in panic
Phobic disorders, other than agoraphobia, are
an unusual cause of self-referral to the ED. In phobias, the anxiety
symptoms are recognized as excessive and occur when the patient
is exposed to, or anticipates exposure to, a specific situation.
This then leads to avoidance of the stimulus to a degree that interferes
with the patient’s life. In social phobia, the anxiety-provoking
situation involves having the attention of others drawn to the patient.
Activities such as speaking in public or meeting strangers create
a fear that the patient will be embarrassed in some way. Specific
phobias are quite common; they involve fear of a very specific stimulus,
such as animals, heights, darkness, or flying.
Post-traumatic stress disorder is
an anxiety reaction to a severe psychosocial stressor, usually life-threatening,
such as military combat, fire, rape, a terrorist event, or natural
disaster.6 Symptoms involve repetitive and intrusive
memories of the event, nightmares, emotional numbing, survivor guilt,
and different degrees of depression and anxiety. Substance abuse
is a frequent complication.
Obsessive-compulsive disorder is a mental disorder
in which the patient experiences intrusive thoughts or images that
cannot be eliminated from the mind. Typical thoughts involve images
of graphic violence to self or others, contamination, or perverse
sexual behavior that the patient would not carry out but nevertheless
obsessively fantasizes about. To control the obsessive thoughts,
the individual may engage in compulsive behavior or rituals, such
as excessive washing, repetitive checking, or counting. When the
obsessions and compulsions occupy a great deal of time, the patient
may become significantly disabled and seek psychiatric attention.
The sense of helplessness and the impairment can lead to the development
Many patients have particular complaints or symptoms
for which no medical explanation can be identified. These symptoms
must cause the patient significant distress or impairment in social,
occupational, or other areas of functioning. When a physical cause
has been clearly eliminated and the complaint is not delusional
or occurring in the context of a depression or anxiety disorder,
somatoform disorders may be considered in the differential diagnosis.
When the complaint involves a loss of function, usually in the neurologic
system (e.g., paralysis, blindness, or numbness) and psychological
factors are deemed etiologic, a conversion disorder may
be present. Conversion disorders are much more common in culturally
and psychologically unsophisticated persons. This diagnosis should
be made with extreme caution, if at all, in the ED, because studies
indicate that many patients diagnosed with conversion disorder eventually
develop signs of a physical disorder that explains the symptom.
For further discussion of conversion disorder, see Chapter 288, Conversion Disorder.
Some patients have a wide variety of complaints
and long, complicated histories of medical problems that have no
apparent medical cause. Such individuals may have somatization
disorder, a disorder beginning in the teens and twenties,
usually in women, and leading to considerable unnecessary diagnostic
and surgical intervention. The prototypical patient is a middle-aged
woman who describes a “positive review of systems” in a
dramatic and confusing way. As with conversion disorder, a diagnosis of
somatization disorder should not be made on the basis of an ED visit, but
the identification of somatizing behavior is useful for future reference,
because patients frequently make repeated contacts with medical providers.
Hypochondriasis may be diagnosed
when the patient is preoccupied with fears of serious illness, fears
that persist despite appropriate medical evaluation and reassurance.
When pain is the sole complaint and the intensity and secondary
disability are unexplained by a known physical ailment, a diagnosis
of pain disorder may be considered.
The dissociative disorders comprise a group of
uncommon and poorly understood conditions in which the central feature
is a sudden alteration in the normal integration of identity and
consciousness. The dissociation often occurs under severe stress
and may or may not be recurrent, although it is rarely permanent.
The forms of dissociative state relevant to emergency practice are dissociative
amnesia, a temporary loss of memory for important personal
details related to a traumatic or stressful situation that is not
due to a medical cause, and dissociative fugue,
in which a similar loss of memory and assumption of a new identity
are accompanied by travel away from home. Dissociative disorders
are difficult to distinguish from malingering,
in which an individual in pursuit of a clear goal, such as avoiding
incarceration or military duty, may consciously feign amnesia. As
always, medical illnesses and drug intoxication that may cause loss
of memory, such as that resulting from transient global amnesia,
must be ruled out.
Other conditions in this category include dissociative
disorder (multiple personality disorder) and depersonalization disorder. Dissociative
disorder is characterized by the presence of two or more
distinct entities that recurrently take control of a person’s
behavior. Depersonalization disorder is a condition
in which the individual has recurrent feelings of being detached
from his or her mind or body.
Factitious disorders are characterized by physical or psychological
symptoms that are exhibited in order to assume a sick role. Patients
may fabricate complaints, falsify vital sign values, self-inflict
an illness, or exaggerate a preexisting medical condition. A factitious
disorder demonstrates a psychological need to be in the sick role
without external incentives.
Malingering is the intentional invention or exaggeration of physical
or psychological symptoms for external gain. The external gain may
be maladaptive to avoid work or obtain drugs or adaptive in response
to being an enemy combatant in wartime. Malingering is distinguished
from factitious disorders by the presentation of symptoms for a
known secondary gain.
The two primary eating disorders are anorexia nervosa and bulimia
nervosa. Anorexia nervosa is characterized by refusal
to maintain normal body weight accompanied by intense fear of gaining
weight or becoming fat and a disturbance in the body image. It is
commonly seen in adolescent and young adult females with amenorrhea. Bulimia
nervosa is a condition that features binge eating, a sense
of a lack of control over eating, and inappropriate compensatory
behaviors to prevent weight gain. These compensatory behaviors usually
involve purging but may also include laxative abuse.
Sleep disorders are thought to be caused by abnormalities in
the sleep-wake generating or timing mechanism. Primary dyssomnias
are disorders related to initiation or maintenance of sleep or excessive
sleep and include primary insomnia, primary hypersomnia, circadian
rhythm sleep disorder, and narcolepsy. Parasomnias are disorders
related to abnormal sleep behavior or physiologic events and include
nightmare disorder, sleep terror, and sleepwalking.