CHAPTER 5: Behavior and Mental Status




As clinicians, we are uniquely poised to detect clues to mental illness and harmful behavior through empathic listening and close observation. Nonetheless, these clues are often missed. Recognizing mental illness is especially important given its significant prevalence and morbidity, the high likelihood that it is treatable, the shortage of psychiatrists, and the increasing importance of primary care clinicians as the first to encounter the patient’s distress.[1],[2]

The prevalence of mental health disorders in U.S. adults in 2012 was 18%, affecting 43.7 million people; yet, only 41% received treatment.[3] Even for those receiving care, adherence to treatment guidelines in primary care offices is ;50% and disproportionately lower for ethnic minorities.[4]–[6]

Recognizing Mental Disorders

This chapter presents:

  • Common symptoms and behaviors suggestive of mental health disorders
  • Concepts that guide history taking and the general assessment of mental health
  • Priorities for mental health promotion and counseling, and
  • Components of the mental status examination, a structured framework for formal assessment of behavioral and mental health disorders, and a major component of the examination of the nervous system (Fig. 5-1).

FIGURE 5-1 Assessment of mental status can be challenging.

Assessment of mental status can be challenging.

See Chapter 17, The Nervous System, pp. 711–796.

Mental health disorders are commonly masked by other clinical conditions, calling for sensitive and careful inquiry. Learn to look for the interaction of anxiety and depression in patients with substance abuse, termed “dual diagnosis,” because both must be treated for the patient to achieve optimal function.

Watch for underlying psychiatric conditions in “difficult encounters” and patients with unexplained symptoms.[7] Explore the outlook of patients with chronic illness, a group that is especially vulnerable to depression and anxiety.[8] Finally, bear in mind that nearly half of those with any single mental disorder meet the criteria for one or more additional disorders, with severity strongly related to comorbidity.[9]

Symptoms and Behavior

Understanding Symptoms: What Do They Mean?

Changing Paradigms for Understanding Symptoms

Sorting the array of symptoms encountered in an office visit is an ongoing challenge. Unlike physical signs, symptoms are not observable. Traditionally, dualistic or binary explanatory models of symptoms have prevailed. Symptoms have been viewed as psychological, reflecting a mental or emotional state, or physical, relating to a body sensation such as pain, fatigue, or palpitations.

Physical symptoms, often termed somatic in the mental health literature, prompt more than 50% of U.S. office visits.[10] Common somatic complaints include: pain from headache, backache, or musculoskeletal conditions; gastrointestinal symptoms; sexual or reproductive symptoms; and neurologic symptoms such as dizziness or loss of balance.

Approximately 5% of somatic symptoms are acute, triggering immediate evaluation.[11] Another 70% to 75% are minor or self-limited and resolve in 6 weeks. Nevertheless, approximately 25% of patients have persisting and recurrent symptoms that elude assessment and fail to improve. Overall, 30% of symptoms are medically unexplained.

Some involve single complaints that persist longer than others, for example, back pain, headache, or musculoskeletal pain. Others present as clusters in functional syndromes, such as irritable bowel syndrome, fibromyalgia, chronic fatigue, temporomandibular joint disorder, and multiple chemical sensitivity.

Experts now propose that physical and psychological symptoms are interactive and represent “a varying mix of disease and nondisease input” that lies along a spectrum from medical to mental disorders.[11] Evidence shows that symptom etiology is often multifactorial, lacking a single cause; and that often, there are several related symptoms or symptom clusters rather than single complaints. The integrative continuum model leads to explanations that are less likely to be “simplified, reductionistic, or mechanistic.”

Watch for emerging schemas that place symptoms along a causative spectrum with five nodal points: symptoms like wheezing, with a clear medical cause; functional somatic syndromes like irritable bowel syndrome; “symptom-only diagnoses” such as low back pain; symptoms associated with psychological conditions, like fatigue in depression; and finally, medically unexplained symptoms.

Changes have also occurred in the classification of somatic syndromes in the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) of 2013. When patients have “distressing somatic symptoms plus abnormal thoughts, feelings, and behaviors in response to these symptoms,” clinicians can consider the diagnosis of somatic symptom and related disorders.[12] These patients have prominent somatic symptoms associated with significant distress and impairment and are seen more often in primary care and medical settings than in psychiatric and mental health settings.

They may have accompanying medical disorders. The DSM-5 notes that “a distinctive characteristic of the many individuals with somatic symptom disorder is not the somatic symptoms per se, but instead the way they present and interpret them.” This change in diagnostic criteria emphasizes the presence of positive symptoms, and moves away from relying on medically unexplained symptoms and the absence of a medical cause, which can be difficult to determine. The prevalence of somatic symptom disorders is estimated at 5% to 7%

See Table 5-1, Somatic Symptom and Related Disorders, p. 169, for types of somatic symptom disorders and guidelines for management.

TABLE 5-1 Somatic Symptom and Related Disorders

Type of Disorder Diagnostic Features
Somatic symptom disorder Somatic symptoms are either very distressing or result in significant disruption of functioning, as well as excessive and disproportionate thoughts, feelings, and behaviors related to those symptoms. Symptoms should be specific if with predominant pain.
Illness anxiety disorder Preoccupation with having or acquiring a serious illness where somatic symptoms, if present, are only mild in intensity.
Conversion disorder Syndrome of symptoms of deficits mimicking neurologic or medical illness in which psychological factors are judged to be of etiologic importance.
Psychological factors affecting other medical conditions Presence of one or more clinically significant psychological or behavioral factors that adversely affect a medical condition by increasing the risk for suffering, death, or disability
Factitious disorder Falsification of physical or psychological signs or symptoms, or induction of injury or disease, associated with identified deception. The individual presents himself or herself as ill, impaired, or injured even in the absence of external rewards.
Other Related Disorders or Behaviors
Body dysmorphic disorder Preoccupation with one or more perceived defects or flaws in physical appearance that are not observable or appear only slight to others.
Dissociative disorder Disruption of and/or discontinuity in the normal integration of consciousness, memory, identity, emotion, perception, body representation, motor control, and behavior.
Note to readers: Regarding tables in past editions on mood, anxiety, and psychotic disorders, per current DSM-5 copyright, readers are referred to the DSM-5 for further diagnostic information.

Medically Unexplained Symptoms

Patients with medically unexplained symptoms fall into heterogeneous groupings ranging from selected impairment to behaviors meeting DSM-5 criteria for mood and somatic symptom disorders.[13],[14] Many patients do not report symptoms of anxiety and depression, the most common mental health disorders in the general population, but focus on physical concerns instead (Fig. 5-2). Two-thirds of patients with depression, for example, present with physical complaints, and half report multiple unexplained or somatic symptoms.[14]

Furthermore, functional syndromes have been shown to “frequently co-occur and share key symptoms and selected objective abnormalities.”[15] Overlap rates for fibromyalgia and chronic fatigue syndrome in an analysis of 53 studies ranged from 34% to 70%. Failure to recognize the admixture of physical symptoms, functional syndromes, and common mental disorders—anxiety, depression, unexplained and somatoform symptoms, and substance abuse—add to the burden of patient undertreatment and poor quality of life.

Authors of the first randomized controlled intervention trial for patients with medically unexplained symptoms advise viewing such symptoms as “a generalized warning sign of underlying psychological distress, of which depression is an advanced manifestation.”[16]

FIGURE 5-2 Clinicians often encounter symptoms not easily diagnosed.

Clinicians often encounter symptoms not easily diagnosed.

The “Difficult Encounter.”

Patients with unexplained and somatic symptoms are often frequent users of the health care system and labeled as “difficult patients.” Patient depression and anxiety “make physician ratings of difficult encounters three times more likely, and somatization increases this likelihood nine-fold.”[17] A growing literature reveals that 15% to 20% of primary care visits, or up to three to four visits a day, are considered difficult.[7]

In the difficult encounter dyad, clinician factors have emerged that include job stress and burnout, anxiety and depression in the clinician, less clinical experience, and aversion to the psychosocial aspects of care.[18],[19] Clinicians are urged to identify the many variables associated with these encounters, identify their own underlying negative emotions, adapt their approach and redirect the encounter, and explore what makes the encounter difficult with the patient.[20],[21] In the words of an expert:

“Celebrate the well-navigated difficult encounter. Dealing with difficulty signifies mastery rather than weakness. Olympic dives are rated in terms of difficulty, as are mountain climbs, hiking trails, musical works, crossword puzzles, and highly technical procedures. Partnering with patients in the challenging aspects of their health, lives, or medical care is a stepping stone to surmounting together the difficult encounter.”[7]

Mental Disorders and Unexplained Symptoms in Primary Care Settings

Mental Disorders in Primary Care

  • Approximately 20% of primary care outpatients have mental disorders, but 50% to 75% of these disorders are undetected and untreated.22,23
  • Prevalence of mental disorders in primary care settings is roughly as follows22,24–26:
    • Anxiety—20%
    • Mood disorders including dysthymia, depressive, and bipolar disorders—25%
    • Depression—10%
    • Somatoform disorders—10% to 15%
    • Alcohol and substance abuse—15% to 20%

Explained and Unexplained Symptoms

  • Physical symptoms account for approximately 50% of office visits.
  • Roughly one-third of physical symptoms are unexplained; in 20% to 25% of patients, physical symptoms become chronic or recurring.10,14
  • In patients with unexplained symptoms, the prevalence of depression and anxiety exceeds 50% and increases with the total number of reported physical symptoms,10,14 making detection and “dual diagnosis” important clinical goals.

Common Functional Syndromes

  • Co-occurrence rates for common functional syndromes such as irritable bowel syndrome, fibromyalgia, chronic fatigue, temporomandibular joint disorder, and multiple chemical sensitivity reach 30% to 90%, depending on the disorders compared.15
  • The prevalence of symptom overlap is high in the common functional syndromes namely, complaints of fatigue, sleep disturbance, musculoskeletal pain, headache, and gastrointestinal problems.
  • The common functional syndromes also overlap in rates of functional impairment, psychiatric comorbidity, and response to cognitive and antidepressant therapy.

Mental Health Screening

Unexplained conditions lasting more than 6 weeks are increasingly recognized as chronic disorders that should prompt screening for depression, anxiety, or both. Because screening all patients is time consuming and expensive, experts recommend a two-tier approach: brief screening questions with high sensitivity and specificity for patients at risk, followed by more detailed investigation when indicated.

Several groups of patients warrant brief screening because of high risk of coexisting depression and anxiety. Recent studies have helped clarify overlap symptoms and functional syndromes and provide streamlined practical screening tools suitable for office care.[27] A well-established instrument to aid in office diagnosis is the PRIME-MD (Primary Care Evaluation of Mental Disorders); however, it contains 26 questions and takes up to 10 minutes to complete.[25]

The DSM-5 acknowledges the diagnostic challenges facing primary care providers and has reduced the total number of disorders as well as their subcategories in the reclassification of Somatic Symptoms and Related Disorders. Improved screening tools for office use and management will continue to emerge.

Patient Indications for Mental Health Screening

  • Medically unexplained physical symptoms—more than half have depression or anxiety disorder
  • Multiple physical or somatic symptoms or “high symptom count”
  • High severity of the presenting somatic symptom
  • Chronic pain
  • Symptoms for more than 6 weeks
  • Physician rating as a “difficult encounter”
  • Recent stress
  • Low self-rating of overall health
  • Frequent use of health care services
  • Substance abuse

Chronic pain may be a spectrum disorder in patients with anxiety, depression, or somatic symptoms. See Chapter 4, Beginning the Physical Examination: General Survey, Vital Signs, and Pain, pp. 111–146.

High-Yield Screening Questions for Office Practice


  • Over the past 2 weeks, have you felt down, depressed, or hopeless?22,28,29
  • Over the past 2 weeks, have you felt little interest or pleasure in doing things (anhedonia)?


Anxiety disorders include generalized anxiety disorder, social phobia, panic disorder, posttraumatic stress disorder, and acute stress disorder.30–33

  • Over the past 2 weeks, have you been feeling nervous, anxious, or on edge?
  • Over the past 2 weeks, have you been unable to stop or control worrying?
  • Over the past 4 weeks, have you had an anxiety attack—suddenly feeling fear or panic?

Illness Anxiety Disorder (Replaces Hypochondriasis in DSM-5)

  • Whiteley Index: 14-item self-rating scale34,35

Substance-Related and Addictive Disorders

  • CAGE questions adapted for alcohol and drug abuse—see Chapter 3, Interviewing and the Health History, p. 97.


  • PRIME-MD (Primary Care Evaluation of Mental Disorders) for the five most common disorders in primary care: depression, anxiety, alcohol, somatoform, and eating disorders; 26-item patient questionnaire followed by clinician evaluation; takes approximately 10 minutes.36
  • PRIME-MD Patient Health Questionnaire, available as patient health questionnaire for self-rating; takes approximately 3 minutes.36

Personality Disorders

Patients with personality disorders can also display problematic office behaviors that escape diagnosis. The DSM-5 characterizes these disorders as “an enduring pattern of inner experience and behavior that deviates markedly from the expectations of the individual’s culture, is pervasive and inflexible, has an onset in adolescence or early adulthood, is stable over time, and leads to distress or impairment.” These patients have dysfunctional interpersonal coping styles that disrupt and destabilize their relationships, including those with health care providers.

A recent study reports an overall prevalence of 9%, with prevalence of the three subcomponent clusters of 5.7% for odd and eccentric disorders; 1.5% for dramatic, emotional, or erratic disorders; and 6% for anxious or fearful disorders.[12] Personality disorders co-occur at high frequencies with alcohol and substance abuse and with the axis I disorders of depression, anxiety disorders, bipolar disorder, attention deficit hyperactivity disorder, autism spectrum disorders, anorexia nervosa, bulimia nervosa, and schizophrenia.[37] Note that DSM-5 section II continues “the categorical perspective that personality disorders are qualitatively distinct clinical syndromes.”

Section III presents an alternative approach to guide further research, namely a dimensional perspective that characterizes personality disorders as “impairments in personality functioning and pathological personality traits” that “merge imperceptibly into normality and into one another.” For more detailed diagnostic criteria, beyond the scope of this book, consult the DSM-5.

Personality Disorders: DSM-5 Section II

Cluster/Personality Type Characteristic Behavior Patterns
A: Odd or Eccentric Disorders
  •  Paranoid
  •  Schizoid
  •  Schizotypal
Distrust and suspiciousness
Detachment from social relations with a restricted emotional range
Eccentricities in behavior and cognitive distortions; acute discomfort in close relationships
B: Dramatic, Emotional or Erratic Disorders
  •  Antisocial
  •  Borderline
  •  Histrionic
  •  Narcissistic
Disregard for, and violation of, the rights of others
Instability in interpersonal relationships, self-image and affective regulation; impulsivity
Excessive emotionality and attention seeking
Persisting grandiosity, need for admiration and lack of empathy
C: Anxious or Fearful Disorders
  •  Avoidant
  •  Dependent
  •  Obsessive–compulsive
Social inhibition, feelings of inadequacy and hypersensitivity to negative evaluation
Submissive and clinging behavior related to an excessive need to be taken care of
Preoccupation with orderliness, perfectionism, and control

Note that in DSM-5, the dimensional model reduces these disorders to six categories: antisocial, avoidant, borderline, narcissistic, obsessive–compulsive, and schizotypal, and emphasizes self and interpersonal functioning.

Sources: Adapted from Schiffer RB. Ch 420, Psychiatric disorders in medical practice, in Cecil Textbook of Medicine, 22nd ed. Philadelphia: Saunders, 2004, p. 2628; American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 5th Ed. Washington, DC: American Psychiatric Press, 2013.

Borderline Personality Disorder

Patients with borderline personality disorders are especially challenging. These patients show “a pervasive pattern of instability of interpersonal relationships, self-image, and affects, and marked impulsivity.”[12] They make “frantic efforts to avoid real or imagined abandonment” and show recurrent suicidal behavior, gestures, or threats, or self-mutilating behavior. Prevalence in primary care practices is 6%, though the diagnosis is often missed.[38],[39]

More than 90% of patients with this disorder meet criteria for other personality disorders. Many have coexisting mood, anxiety, and substance abuse disorders. Presenting symptoms overlap with depression, anxiety, substance abuse, and eating disorders, which complicate diagnosis. In clinical settings, over 75% of those affected are women, and the disorder shows a strong genetic and familial pattern.[40] More than half lose their jobs because of interpersonal problems, and roughly one-third experience sexual abuse.

Patients often report feeling depressed and empty, with mood swings that spiral out of control leading to feelings of rage, sadness, and anxiety. To clinicians, these patients may appear demanding, disruptive, or manipulative. Recognition of borderline features is essential for patient understanding, reduction of patient self-harm, and referral for expert evaluation.