After Chapter 7.2, you will be able to:
As mentioned earlier, the DSM-5 categorizes common symptoms into 20 diagnostic classes. Many of these classes represent significant revisions from the DSM-5’s immediate predecessor, the DSM-IV-TR. The most heavily tested diagnostic classes on the MCAT are schizophrenia spectrum and other psychotic disorders, depressive disorders, bipolar and related disorders, anxiety disorders, obsessive–compulsive and related disorders, trauma- and stressor-related disorders, dissociative disorders, somatic symptom and related disorders, and personality disorders.
Schizophrenia is the prototypical psychotic disorder. According to the DSM-5, individuals with a psychotic disorder suffer from one or more of the following conditions: delusions, hallucinations, disorganized thought, disorganized behavior, catatonia, and negative symptoms. For an individual to be given the diagnosis of schizophrenia, he or she must show continuous signs of the disturbance for at least six months, and this six-month period must include at least one month of "active symptoms" (delusions, hallucinations, or disorganized speech).
The term schizophrenia is a relatively recent term, coined in 1911 by Eugen Bleuler. Before Bleuler, schizophrenia was called dementia praecox. Schizophrenia literally means “split mind” because the disorder is characterized by distortions of reality and disturbances in the content and form of thought, perception, and affect. Unfortunately, this has led to confusion with dissociative identity disorder (formerly multiple personality disorder). By split mind, Bleuler did not mean that the mind is split into different personalities, but that the mind is split from reality.
Symptoms of schizophrenia are divided into positive and negative types. Positive symptoms are behaviors, thoughts, or feelings added to normal behavior. Examples include delusions and hallucinations, disorganized thought, and disorganized or catatonic behavior. Positive symptoms are considered by some to be two distinct dimensions—the psychotic dimension (delusions and hallucinations) and the disorganized dimension (disorganized thought and behavior)—perhaps with different underlying causes. Negative symptoms are those that involve the absence of normal or desired behavior, such as disturbance of affect and avolition.
Delusions are false beliefs discordant with reality and not shared by others in the individual’s culture that are maintained in spite of strong evidence to the contrary. Common delusions include delusions of reference, persecution, and grandeur. Delusions of reference involve the belief that common elements in the environment are directed toward the individual. For example, a person with a delusion of reference may believe that characters in a TV show are talking to him directly. Delusions of persecution involve the belief that the person is being deliberately interfered with, discriminated against, plotted against, or threatened. Delusions of grandeur, also common in bipolar I disorder, involve the belief that the person is remarkable in some significant way, such as being an inventor, historical figure, or religious icon. Other common delusions involve the concept of thought broadcasting, which is the belief that one’s thoughts are broadcast directly from one’s head to the external world, and thought insertion, the belief that thoughts are being placed in one’s head.
The fact that delusions must be considered deviant from the society in which an individual lives provides an excellent opportunity for the MCAT to integrate mental illness and sociology. For example, a belief in shamanism—which is common in the Caribbean, Central and South America, Africa, and in some Native American tribes—would not be considered a delusion within societies that endorse shamanic medicine.
Hallucinations are perceptions that are not due to external stimuli but have a compelling sense of reality. The most common form of hallucination is auditory, involving voices that the individual perceives as coming from inside or outside his or her head. Visual and tactile hallucinations are less common, but may be seen in drug use or withdrawal. Olfactory and gustatory hallucinations are even less common, but may be experienced during the aura before a seizure.
Disorganized thought is characterized by loosening of associations. This may be exhibited as speech in which ideas shift from one subject to another in such a way that a listener would be unable to follow the train of thought. A patient’s speech may be so disorganized that it seems to have no structure—as though it were just words thrown together incomprehensibly. This is sometimes called word salad. In fact, a person with schizophrenia may even invent new words, called neologisms.
Word salad can be seen in severe schizophrenia as well as Wernicke’s (receptive) aphasia. Patients will string together unrelated words, although the prosody of the speech (its rhythm, stress, and intonation) remains intact. Aphasias are discussed in Chapter 3 of MCAT Behavioral Sciences Review.
Disorganized behavior refers to an inability to carry out activities of daily living, such as paying bills, maintaining hygiene, and keeping appointments. Catatonia refers to certain motor behaviors characteristic of some people with schizophrenia. The patient’s spontaneous movement and activity may be greatly reduced or the patient may maintain a rigid posture, refusing to be moved. At the other extreme, catatonic behavior may include useless and bizarre movements not caused by any external stimuli, echolalia (repeating another’s words), or echopraxia (imitating another’s actions).
Negative symptoms of schizophrenia include disturbance of affect and avolition. Affect refers to the experience and display of emotion. Affective symptoms may include blunting, in which there is a severe reduction in the intensity of affect expression; flat affect (emotional flattening), in which there are virtually no signs of emotional expression; or inappropriate affect, in which the affect is clearly discordant with the content of the individual’s speech. For example, a patient with inappropriate affect may begin to laugh hysterically while describing a parent’s death. Interestingly, it has become more difficult to assess the affective aspects of schizophrenia because the antipsychotic medications used in treatment frequently blunt and flatten affect as well. Finally, avolition is marked by decreased engagement in purposeful, goal-directed actions.
When the MCAT tests schizophrenia, it is likely to include a connection to sociology through the downward drift hypothesis, which states that schizophrenia causes a decline in socioeconomic status, leading to worsening symptoms, which sets up a negative spiral for the patient toward poverty and psychosis. This is why rates of schizophrenia are much, much higher among the homeless and indigents.
Before schizophrenia is diagnosed, a patient often goes through a phase characterized by poor adjustment. This phase is called the prodromal phase. The prodromal phase is exemplified by clear evidence of deterioration, social withdrawal, role functioning impairment, peculiar behavior, inappropriate affect, and unusual experiences. This phase is followed by the active phase of symptomatic behavior. If schizophrenia development is slow, the prognosis is especially poor. If the onset of symptoms is intense and sudden, the prognosis is better.
Sadness is a natural part of life, especially in response to stressful life events like the death of a loved one. During periods of sadness, one might call him- or herself depressed. However, periodic sadness in response to life events is not a mental disorder. Depressive disorders, in contrast, must meet certain severity and duration requirements for diagnosis.
The most common first-line treatment for depression is the class of medications called selective serotonin reuptake inhibitors (SSRIs). These block the reuptake of serotonin by the presynaptic neuron, resulting in higher levels of serotonin in the synapse and relief of symptoms. The nervous system is outlined in Chapter 1 of MCAT Behavioral Sciences Review and Chapter 4 of MCAT Biology Review.
Major depressive disorder is a mood disorder characterized by at least one major depressive episode. A major depressive episode is a period of at least two weeks with at least five of the following symptoms: prominent and relatively persistent depressed mood, loss of interest in all or almost all formerly enjoyable activities (anhedonia), appetite disturbances, substantial weight changes, sleep disturbances, decreased energy, feelings of worthlessness or excessive guilt (sometimes delusional), difficulty concentrating or thinking, psychomotor symptoms (feeling “slowed down”), and thoughts of death or attempts at suicide; at least one of the symptoms must be depressed mood or anhedonia. In order for major depressive disorder to be diagnosed, these symptoms must cause significant distress or impairment in functioning. As many as 15 percent of individuals with this disorder die by suicide.
Symptoms of a major depressive episode: SIG E. CAPS
Sadness +
A diagnosis of persistent depressive disorder is given to individuals who suffer from dysthymia, a depressed mood that isn’t severe enough to meet the criteria of a major depressive episode, most of the time for at least two years. Individuals with major depressive disorder that lasts at least two years can also be given this diagnosis. Individuals with this disorder may also suffer from a combination of dysthymia and occasional major depressive episodes.
Seasonal affective disorder (SAD) is not a freestanding diagnosis in the DSM-5, but is best categorized as major depressive disorder with seasonal onset. In this case, depressive symptoms are present only in the winter months. This disorder may be related to abnormal melatonin metabolism; it is often treated with bright light therapy, where the patient is exposed to a bright light for a specified amount of time each day, as demonstrated with a plant in Figure 7.1.
The bipolar disorders (formerly known as manic depression) are a major type of mood disorder characterized by both depression and mania. Manic episodes are characterized by abnormal and persistently elevated mood lasting at least one week with at least three of the following: increased distractibility, decreased need for sleep, inflated self-esteem or grandiosity (beliefs that one is all-powerful, famous, or wealthy), racing thoughts, increased goal-directed activity or agitation, pressured speech or increased talkativeness, and involvement in high-risk behavior. Manic episodes generally have a more rapid onset and a briefer duration than depressive episodes and may include psychosis. Bipolar I disorder has manic episodes with or without major depressive episodes, whereas bipolar II disorder has hypomania with at least one major depressive episode. In contrast to mania, hypomania typically does not significantly impair functioning, nor are there psychotic features, although the individual may be more energetic and optimistic. Finally, cyclothymic disorder consists of a combination of hypomanic episodes and periods of dysthymia that are not severe enough to qualify as major depressive episodes.
Symptoms of a manic episode: DIG FAST
Depressive and manic episodes are essentially two sides of the same coin: Depression is associated with low norepinephrine and serotonin levels, and manic episodes are associated with high levels of these neurotransmitters. When patients are put on treatment for depression, they must be watched for signs of mania because antidepressant medications may unmask an underlying undiagnosed bipolar disorder.
Many causes have been proposed for mood disorders, ranging from genetics to sociocultural factors. The most common explanation revolves around the neurotransmitters norepinephrine and serotonin. These two are often linked together into what is called the monoamine or catecholamine theory of depression. This theory holds that too much norepinephrine and serotonin in the synapse leads to mania, while too little leads to depression. Although more recent research has shown that it is not that simple, you should be aware of this theory for the MCAT.
There are more than ten disorders listed in the anxiety disorders portion of the DSM-5. This type of disorder is the most common psychiatric disorder in women of all ages. For men, in contrast, substance use disorder is the most common psychiatric disorder.
For all anxiety disorders, clinicians must rule out hyperthyroidism—excessive levels of the thyroid hormones triiodothyronine (T3) and thyroxine (T4)—because increasing the whole body’s metabolic rate will create anxiety-like symptoms. Thyroid function is discussed in Chapter 5 of MCAT Biology Review.
Generalized anxiety disorder is common in the population and is defined as a disproportionate and persistent worry about many different things—making mortgage payments, doing a good job at work, returning emails, political issues, and so on—for at least six months. These individuals often have physical symptoms like fatigue, muscle tension, and sleep problems that accompany the worry.
The most common type of anxiety disorder is a phobia. A phobia is an irrational fear of something that results in a compelling desire to avoid it. Most of the phobias that you are probably familiar with are what the DSM-5 calls specific phobias. A specific phobia is one in which anxiety is produced by a specific object or situation. For example, claustrophobia is an irrational fear of closed places, acrophobia is an irrational fear of heights, and arachnophobia is an irrational fear of spiders, as shown in Figure 7.2.
Social anxiety disorder is characterized by anxiety that is due to social situations. Individuals with social anxiety disorder have persistent fear when exposed to social or performance situations that may result in embarrassment; for example, delivering a speech, socializing at a party, or using a public restroom.
Agoraphobia is an anxiety disorder characterized by a fear of being in places or in situations where it might be hard for an individual to escape. These individuals tend to be uncomfortable leaving their homes for fear of a panic attack or exacerbation of another mental illness.
Another type of anxiety disorder to know for the MCAT is panic disorder. This disorder consists of repeated panic attacks. Symptoms of a panic attack include fear and apprehension, trembling, sweating, hyperventilation, and a sense of unreality. The severity of a panic attack should not be underestimated: these individuals are suddenly struck with what is often described as a sense of impending doom and may be convinced they are about to lose their mind. Even after treatment for panic disorder, symptoms are common, so patients are treated for a long period of time. Panic disorder is frequently accompanied by agoraphobia because of the pervasive fear of having a panic attack in a public location.
Notice that a large number of the symptoms of panic disorder are caused by excess activation of the sympathetic nervous system (autonomic overdrive). These include trembling, sweating, hyperventilation, shortness of breath, a racing heart rate, and palpitations. The autonomic nervous system is discussed in Chapter 1 of MCAT Behavioral Sciences Review and Chapter 4 of MCAT Biology Review.
Formerly classified under anxiety and somatic symptom disorders, the illnesses in this group were relabeled as obsessive–compulsive and related disorders in the DSM-5.
Obsessive–compulsive disorder (OCD) is characterized by obsessions (persistent, intrusive thoughts and impulses), which produce tension, and compulsions (repetitive tasks) that relieve tension but cause significant impairment in a person’s life. The relationship between the two is key: obsessions raise the individual’s stress level, and the compulsions relieve this stress. For instance, a person might obsess about dirt and compulsively wash his hands to neutralize the anxiety produced by the obsession.
In body dysmorphic disorder, a person has an unrealistic negative evaluation of his or her personal appearance and attractiveness, usually directed toward a certain body part. This person sees her nose, skin, or stomach as ugly or even horrific when it is actually normal in appearance. This body preoccupation also disrupts day-to-day life, and the sufferer may seek multiple plastic surgeries or other extreme interventions.
By far, the most notable disorder in this category is posttraumatic stress disorder (PTSD). PTSD occurs after experiencing or witnessing a traumatic event, such as war, a home invasion, rape, or a natural disaster, and consists of intrusion symptoms, avoidance symptoms, negative cognitive symptoms, and arousal symptoms. Intrusion symptoms include recurrent reliving of the event, flashbacks, nightmares, and prolonged distress. Avoidance symptoms include deliberate attempts to avoid the memories, people, places, activities, and objects associated with the trauma. Negative cognitive symptoms include an inability to recall key features of the event, negative mood or emotions, feeling distanced from others, and a persistent negative view of the world. Finally, arousal symptoms include an increased startle response, irritability, anxiety, self-destructive or reckless behavior, and sleep disturbances. To meet the criteria of PTSD, a particular number of these symptoms must be present for at least one month. If the same symptoms last for less than one month (but more than three days), it may be called acute stress disorder.
In dissociative disorders, the person avoids stress by escaping from his identity. The person otherwise still has an intact sense of reality. Examples of dissociative disorders include dissociative amnesia, dissociative identity disorder (formerly multiple personality disorder), and depersonalization/derealization disorder.
Dissociative amnesia is characterized by an inability to recall past experiences. The qualifier dissociative simply means that the amnesia is not due to a neurological disorder. This disorder is often linked to trauma. Some individuals with this disorder may also experience dissociative fugue: a sudden, unexpected move or purposeless wandering away from one’s home or location of usual daily activities. Individuals in a fugue state are confused about their identity and can even assume a new identity. Significantly, they may actually believe that they are someone else, with a complete backstory.
In dissociative identity disorder (DID, formerly multiple personality disorder), there are two or more personalities that recurrently take control of a person’s behavior, as represented in Figure 7.3. This disorder results when the components of identity fail to integrate. In most cases, the patients have suffered severe physical or sexual abuse as young children. After much therapy, the personalities can sometimes be integrated into one. The existence of dissociative identity disorder is justifiably debated within the medical community, but its characteristics are still important to recognize on Test Day.
One of the first and most famous cases of dissociative identity disorder in the media is Shirley Ardell Mason, also known as “Sybil,” who had at least 13 separate personalities. Mason underwent years of therapy in an attempt to combine her personalities into a single one. Two separate TV movies, both called Sybil, have been produced to tell the story of Sybil’s struggle with this disorder.
In depersonalization/derealization disorder, individuals feel detached from their own mind and body (depersonalization), or from their surroundings (derealization). This often presents as a feeling of automation, and can have findings like a failure to recognize one’s reflection. An out-of-body experience is an example of depersonalization. Derealization is often described as giving the world a dreamlike or insubstantial quality. They may also experience depersonalization and derealization simultaneously. These feelings cause significant impairment of regular activities. However, even during these times, the person does not display psychotic symptoms like delusions or hallucinations.
Diagnoses in this category are marked by somatic (bodily) symptoms that cause significant stress or impairment.
Individuals with somatic symptom disorder have at least one somatic symptom, which may or may not be linked to an underlying medical condition, and that is accompanied by disproportionate concerns about its seriousness, devotion of an excessive amount of time and energy to it, or elevated levels of anxiety.
Illness anxiety disorder is characterized by being consumed with thoughts about having or developing a serious medical condition. Individuals with this disorder are quick to become alarmed about their health, and either excessively check themselves for signs of illness or avoid medical appointments altogether. Most patients classified under hypochondriasis in the DSM-IV-TR now fit into somatic symptom disorder if somatic symptoms are present or illness anxiety disorder if they are not.
A conversion disorder is characterized by unexplained symptoms affecting voluntary motor or sensory functions. The symptoms generally begin soon after the individual experiences high levels of stress or a traumatic event, but may not develop until some time has passed after the initiating experience. Examples include paralysis or blindness without evidence of neurological damage. The person may be surprisingly unconcerned by the symptom—what is called la belle indifférence. Conversion disorder was historically called hysteria. The symptoms seen in conversion disorder may sometimes be connected with the inciting event in a literal or poetic way; for example, a woman going blind shortly after watching her son die tragically.
A personality disorder is a pattern of behavior that is inflexible and maladaptive, causing distress or impaired functioning in at least two of the following: cognition, emotions, interpersonal functioning, or impulse control. Personality disorders are considered ego-syntonic, meaning that the individual perceives her behavior as correct, normal, or in harmony with her goals. This is in contrast to the other disorders covered in this chapter that are ego-dystonic, meaning that the individual sees the illness as something thrust upon her that is intrusive and bothersome. In addition to general personality disorder, there are ten personality disorders grouped into three clusters: cluster A (paranoid, schizotypal, and schizoid), cluster B (antisocial, borderline, histrionic, and narcissistic), and cluster C (avoidant, dependent, and obsessive–compulsive). Personality disorder criteria will continue changing over time; the DSM-5 includes a section specifically devoted to research models for redefining personality disorders.
The cluster A personality disorders are all marked by behavior that is labeled as odd or eccentric by others. Its three examples include paranoid, schizotypal, and schizoid personality disorders.
Paranoid personality disorder is marked by a pervasive distrust of others and suspicion regarding their motives. In some cases, these patients may actually be in the prodromal phase of schizophrenia and are termed premorbid.
Schizotypal personality disorder refers to a pattern of odd or eccentric thinking. These individuals may have ideas of reference (similar to delusions of reference, but not as extreme in intensity) as well as magical thinking, such as superstitiousness or a belief in clairvoyance.
Finally, schizoid personality disorder is a pervasive pattern of detachment from social relationships and a restricted range of emotional expression. People with this disorder show little desire for social interactions; have few, if any, close friends; and have poor social skills. It should be noted that neither schizotypal nor schizoid personality disorder are the same as schizophrenia.
The cluster B personality disorders are all marked by behavior that is labeled as dramatic, emotional, or erratic by others. Its four examples include antisocial, borderline, histrionic, and narcissistic personality disorders.
Antisocial personality disorder is three times more common in males than in females. The essential feature of the disorder is a pattern of disregard for and violations of the rights of others. This is evidenced by repeated illegal acts, deceitfulness, aggressiveness, or a lack of remorse for said actions. Many serial killers and career criminals who show no guilt for their actions have this disorder. Additionally, people with this disorder comprise about 20 to 40 percent of prison populations.
Borderline personality disorder is two times more common in females than in males. In this disorder, there is pervasive instability in interpersonal behavior, mood, and self-image. Interpersonal relationships are often intense and unstable. There may be profound identity disturbance with uncertainty about self-image, sexual identity, long-term goals, or values. There is often intense fear of abandonment. Individuals with borderline personality disorder may use splitting as a defense mechanism, in which they view others as either all good or all bad (an angel vs. devil mentality). Suicide attempts and self-mutilation (cutting or burning) are common.
Histrionic personality disorder is characterized by constant attention-seeking behavior. These individuals often wear colorful clothing, are dramatic, and are exceptionally extroverted. They may also use seductive behavior to gain attention.
In narcissistic personality disorder, one has a grandiose sense of self-importance or uniqueness, preoccupation with fantasies of success, a need for constant admiration and attention, and characteristic disturbances in interpersonal relationships such as feelings of entitlement. As used in everyday language, narcissism refers to those who like themselves too much. However, people with narcissistic personality disorder have very fragile self-esteem and are constantly concerned with how others view them. There may be marked feelings of rage, inferiority, shame, humiliation, or emptiness when these individuals are not viewed favorably by others.
The cluster C personality disorders are all marked by behavior that is labeled as anxious or fearful by others. Its three examples include avoidant, dependent, and obsessive–compulsive personality disorders.
In avoidant personality disorder, the affected individual has extreme shyness and fear of rejection. The individual will see herself as socially inept and is often socially isolated, despite an intense desire for social affection and acceptance. These individuals tend to stay in the same jobs, life situations, and relationships despite wanting to change.
Dependent personality disorder is characterized by a continuous need for reassurance. Individuals with dependent personality disorder tend to remain dependent on one specific person, such as a parent or significant other, to take actions and make decisions.
In obsessive–compulsive personality disorder (OCPD), the individual is perfectionistic and inflexible, tending to like rules and order. Other characteristics may include an inability to discard worn-out objects, lack of desire to change, excessive stubbornness, lack of a sense of humor, and maintenance of careful routines. Note that obsessive–compulsive personality disorder is not the same as obsessive–compulsive disorder. Whereas OCD has obsessions and compulsions that are focal and acquired, OCPD is lifelong. OCD is also ego-dystonic (I can’t stop washing my hands because of the germs!), whereas OCPD is ego-syntonic (I just like rules and order!).
Obsessive–compulsive disorder (OCD) and obsessive–compulsive personality disorder (OCPD) are not synonymous. OCD is marked by obsessions (intrusive thoughts causing tension) and compulsions (repetitive tasks that relieve this tension but cause significant impairment). OCPD is a personality disorder in which individuals are perfectionistic and inflexible.