Essentials of Diagnosis
Either obsessions or compulsions:
Obsessions as defined by (1), (2), (3), and (4):
recurrent and persistent thoughts, impulses, or images that are experienced, at some time during the disturbance, as intrusive and inappropriate and that cause marked anxiety or distress
the thoughts, impulses, or images are not simply excessive worries about real-life problems
the person attempts to ignore or suppress such thoughts, impulses, or images or neutralize them with some other thought or action
the person recognizes that the thoughts, impulses, or images are a product of his or her own mind (not imposed from without as in thought insertion)
Compulsions as defined by (1) and (2):
repetitive behaviors (e.g., hand washing, ordering, checking) or mental acts (e.g., praying, counting, repeating works silently) that the person feels driven to perform in response to an obsession, or according to rules that must be applied rigidly
the behavior or mental acts are aimed at preventing or reducing distress or preventing some dreaded event or situation; however, these behaviors or mental acts either are not connected in a realistic way with what they are designed to neutralize or prevent or are clearly excessive
At some point during the course of the disorder, the person has recognized that the obsessions or compulsions are excessive or unreasonable.
Note: This does not apply to children.
The obsessions or compulsions cause marked distress, are time consuming (takes more than 1 hour/day) or significantly interfere with the person’s normal routine, occupation (or academic functioning), or usual social activities or relationships.
If another Axis I disorder is present, the content of the obsessions or compulsions is not restricted to it.
The disturbance is not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication) or a general medical condition.
With poor insight: if, for most of the time during the current episode, the person does not recognize that the obsessions and compulsions are excessive or unreasonable.
General Considerations
Obsessions are unwanted aversive cognitive experiences usually associated with feelings of dread, loathing, or a disturbing sense that something is not right. The individual recognizes (at some point in time) that these concerns are inappropriate in relation to reality and will generally attempt to ignore or suppress them. Compulsions are overt behaviors or covert mental acts performed to reduce the intensity of the aversive obsessions. They may occur as behaviors that are governed by rigid, but often irrelevant, internal specifications. They are inappropriate in nature or intensity in relation to the external circumstances that provoked them.
Lifetime prevalence rates of obsessive–compulsive disorder (OCD) in the United States range between 2% and 3%, but may be slightly lower in certain ethnic subgroups, including African Americans and possibly Hispanics. Lifetime prevalence rates are similar (approximately 2%) in Europe, Africa, Canada, and the Middle East, but appear to be lower (0.5–0.9%) in certain Asian countries (i.e., India and Taiwan). Lower prevalence rates in selected U.S. and other national populations could be related to cultural factors resulting in underreporting of symptoms, or be related to such biological factors as increased resistance to basal ganglia disease. Although OCD is thought to be a lifetime illness, lifetime prevalence rates in young adults are over twice those seen in the elderly. It is unclear whether this observation represents a reporting bias, a waning of symptoms with advancing age, a shorter life expectancy in patients with OCD, or a changing environmental factor relating to the etiology of the illness.
OCD is usually first seen in childhood or early adulthood: 65% of patients have their onset prior to age 25 years, 15% after the age of 35 years, and 30% in childhood or early adolescence. In the latter population, there is a 2:1 preponderance of males; in contrast, OCD in the adult population is slightly more predominant in women. The frequency of OCD in psychiatric practice may be significantly lower than in the general population. Indeed, the incidence of OCD was previously thought to be as low as 0.05% based on psychiatric samples. Low frequency estimates may be related to the intense shame and secrecy associated with this illness and the patients’ reluctance to divulge their symptomatology.
The frequency of specific obsessions and compulsions is fairly constant across populations. Contamination fears are present in approximately 50% of OCD patients, unwarranted fears that something is wrong (called pathologic doubt) in 40%, and other obsessions, including needs for symmetry, fears of harm to self or others, and unwanted sexual concerns, in 25–30%. Checking and decontamination rituals are the predominant rituals in OCD (50–60%). Other rituals, such as arranging, counting, repeating, and repetitive superstitious acts, occur less frequently (30–35%). Most patients with OCD (60%) have multiple obsessions or compulsions.
The only subtype recognized in the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, Text Revision (DSM-IV-TR) is OCD with poor insight. Adults given this diagnosis were previously aware that they were symptomatic but became convinced of the validity of their fears and the necessity of their compulsions as their illness progressed. Children with this diagnosis have not yet developed insight regarding their symptoms.
It has not proved helpful to classify OCD according to a symptom dyad (e.g., contamination-washing) as a means of predicting course of the illness, therapeutic outcome, or other relevant measures. Indeed, most individuals have multiple obsessions and compulsions, and symptom clusters can change over time (e.g., a compulsive hand-washer will lose fear of contamination and develop fears of harming others). It has been more useful to classify subtypes of patients according to their underlying experiences. Patients with OCD can be divided into two subgroups based on experiences of (1) pathologic doubt (e.g., dread and uncertainty) or (2) incompletion, or “not-just-right” perceptions. Individuals within these two subgroups appear to share common symptom clusters, co-morbidities, and treatment prognoses.
OCD can also be classified on the basis of the presence or absence of tics. Patients with tics may respond to a different treatment regimen than do those who do not have tics. Because of the relationship between Tourette syndrome and OCD, these patients may also have other symptoms found in the families of Tourette syndrome patients, such as urges to carry out maladaptive acts and problems with impulse control.
Finally, a subset of OCD patients with schizotypal personality disorder has been characterized. These patients are sometimes mistakenly diagnosed as having schizophrenia (though they lack true category A symptoms), are more likely to have poor insight and poor social functioning, may require a different treatment regimen, and are often refractory to treatment.
Theories of etiology have invoked psychoanalytic (i.e., relating to early childhood experiences), cognitive, posttraumatic, epileptic, traumatic (i.e., brain injury), genetic, and postinfectious processes. The psychoanalytic view has fallen into disfavor in recent years. Likewise, it is no longer thought that symptoms of OCD are a consequence of psychic trauma. In cases where psychic trauma is associated with the onset of symptoms, the experience is thought to potentiate a propensity for developing OCD symptoms in susceptible individuals and does not create the pathology itself.
OCD can result from pathologic processes affecting cerebral functioning. For example, severe head trauma and epilepsy have been associated with obsessive–compulsive symptoms. Disorders affecting the functioning of the basal ganglia have also been associated with OCD, and a postinfectious autoimmune-related form of OCD has been described in children. OCD symptoms in these children frequently occur after an infection with type A β-hemolytic Streptococcus bacteria, with or without classical symptoms of rheumatic fever. In the acute phase of this illness, antibodies directed at streptococcal M-protein react with specific brain proteins located primarily in the basal ganglia and may induce Sydenham chorea (also called St. Vitus’ dance). Obsessions, compulsions, or vocal and motor tics indistinguishable from those seen in Tourette syndrome can be prominent when the chorea is present, although the child may not speak of them if not directly questioned. Sydenham chorea is associated with swelling of the head of the caudate nucleus on magnetic resonance imaging (MRI).
Poststreptococcal antineuronal antibodies have also been detected in cases of abrupt-onset OCD that do not exhibit the symptoms of Sydenham chorea nor any other manifestation of rheumatic fever. OCD symptoms appear in conjunction with increasing antibody titers and remit as titers fall. Autoimmune-related OCD has been described only in children. Adults with OCD, however, may have reduced volume in the caudate region of the basal ganglia. It is conceivable that neuropathologic processes, such as repeated autoimmune inflammation, could irreversibly damage central nervous system (CNS) tissue and result in a chronic form of OCD in adults. It is also possible that certain cases of familial OCD or Tourette syndrome could be related to heritable proteins involved in the autoimmune process.
OCD occurs with greater frequency in family members of OCD patients (10%), as compared to the general population. When combined with subclinical obsessions and compulsions, symptom prevalence rates approach 20% in first-degree relatives. Interestingly, familial rates of OCD are significantly higher in patients with childhood OCD than in patients with adult OCD. This may be related to a heritable tic-related form of OCD with onset in childhood. Although there have been no systematic twin studies of sufficient size to draw conclusions, 65–85% of monozygotic twin pairs with one twin having OCD are concordant for OCD symptoms, whereas only 15–45% of dizygotic twin pairs are so concordant.
OCD has been linked to the proposed autosomal dominant Tourette syndrome (TS) gene. This gene is associated with chronic motor tics, vocal tics, and OCD. Under this genetic model, males carrying the TS gene have a 90–95% probability of developing at least one of these behaviors. Females carrying the TS gene have a lower expression rate (approximately 60%), but a higher proportion will develop OCD. The exact locus of the TS gene has not been identified. Some familial forms of OCD with partial penetrance do not appear to be related to the TS gene. The genetic determinant of this form has not been identified.
Clinical Findings
The clinical hallmarks of obsessions are aversive experiences of dread and uncertainty, or the disturbing sense that something is not right or is incomplete. Obsessive thoughts are the particular ideas associated with obsessive experiences. They are often bizarre or inadequate as explanations for these experiences. Obsessions can take the form of aversive mental images, dread and disgust related to perceived defilement, feelings that something very bad has either happened or is about to happen, or an urgent sense that something that needs to be done has not yet been completed. A sense of immediacy and urgency is almost always associated with the aversive experiences. Obsessions can be present without compulsions, most frequently when the individual recognizes that no action can alleviate the aversive experience. Under such circumstances the individual may only seek reassurance that his or her fears are unfounded or unrealistic.
Compulsions take the form of willed responses directed at reducing the aversive circumstances associated with the obsessive thoughts. They are generally carried out in concordance with the ideation surrounding the obsessions. They can take the form of overt behaviors or silent mental acts such as checking, praying, counting, or some other mental ritual. Mental compulsions differ from obsessive experiences in that they are willed mental acts performed for a purpose, rather than sensory or ideational experiences. Compulsions are usually carried out in a repetitive or stereotyped fashion, although they can be situation specific, dependent on the content of the obsessive thought. Compulsions can also be carried out in the absence of specific obsessive thoughts. In such cases they are usually responses to an urgent sense that something is not right or is incomplete.
Most adults with OCD recognize that their fears and behaviors are unrealistic or excessive. Insight in OCD can vary, however, from states of full awareness that the symptoms are absurd, with a few lingering doubts, through equivocal acknowledgment, to a delusional state in which the individual is convinced of the validity of his or her fear and the necessity of the consequent behavior. Some adults lose insight only during exacerbations of their illness. Others, often with schizotypal personalities, may have true insight only early in the illness, or transiently when their illness is quiescent. The term “overvalued idea” was used in the past to denote an obsessive thought firmly held to be valid. This term is no longer accepted as a construct, because it cannot be practically differentiated from delusional ideation. Patients who have lost insight in regard to their symptoms are considered to belong to a diagnostic subclass of OCD.
Avoidance may be a prominent secondary symptom in OCD. The OCD patient will avoid circumstances that trigger particularly aversive obsessions or lead to time-consuming compulsions. Avoidance, itself, is not a compulsion; but when the illness is severe it can be a prominent clinical feature. In the course of treatment, as avoidance is reduced, a temporary, paradoxical increase in compulsions can occur because of increased exposure to circumstances that trigger them.
OCD stands out among psychiatric disorders in the degree to which the patient’s thoughts and concerns diverge from their awareness of reality. Most OCD patients recognize the absurd nature of their behavior and are acutely aware of demeaning perceptions that others might have if they knew the degree to which they were affected by their illness. They have a strong fear that they will be considered crazy. Ashamed and embarrassed, they are reluctant to disclose their symptoms to anyone who might not understand their illness. As a result, individuals with OCD tend to be highly secretive.
Early in the illness, they will try to hide their symptoms from those who know them. They may delay seeking treatment until their symptoms are noticed by those around them. Many patients will not reveal their illness to their primary physicians. Therapists sometimes will care for a patient for several years before discovering that the patient has OCD. This is particularly true for patients who experience horrific sexual, blasphemous, or violent thoughts and images. These individuals fear that the therapist will believe that they want these scenarios to occur and that they might act inappropriately in concordance with their obsessive thoughts. In short, they fear that the physician will confirm their own fears and self-condemnation. They may leave a therapeutic relationship if they sense that the therapist does not understand the illness.
The combination of secrecy, avoidance of contact with others, and the time-consuming nature of the compulsions may lead to social isolation and secondary depression. Most patients with OCD also experience a heightened sense of internal tension and distress. When their OCD is worse they will describe feelings of desperation and despair, as they are unable to relieve their feelings of dread and uncertainty. It is these feelings that may lead the patient to seek initial treatment.
Patients with OCD may also have an unreasonable fear of losing control. These feelings can be exacerbated by a perceived inability to control their compulsive behavior. The individual with OCD fears that he or she will lose control of natural inhibitions and act in a socially or personally maladaptive manner. Patients with obsessive–compulsive personality disorder (OCPD) have different issues with control; they want control for the positive sense of mastery that it engenders. Patients with OCD often shun true control and responsibility because of their unrealistic fears that they might misuse or abuse it.
Patients with OCD frequently have a parent or life partner who is involved in the illness. There are two pathologic forms of such involvement. The first involves facilitation. By pleading, nagging, demanding, or threatening, the patient will induce others to accommodate to his or her fears and concerns. The facilitator may perform rituals for the patient or permit the patient to control the environment or common time. Facilitation allows the illness to flourish without normal constraints.
The second pathologic interaction is the antagonistic–defensive dyad. Such relationships are adversarial. The antagonistic partner acts in a caustic, demeaning manner and does not understand or accept the nature of the illness. The OCD symptoms are viewed as willful antagonism. The patient reacts in a hostile, defensive manner that aggravates the partner. The hostility, instability, loss of self-esteem, and stress in these interactions exacerbate the symptoms of OCD and lead to further antagonism.
In both forms of pathologic relationship, the patient may use his or her symptoms to control the other person. This can be an unconscious or pseudoconscious process. Facilitating interactions can lead to circumstances in which the patient uses his or her illness to obtain material and emotional benefits. In antagonistic–defensive interactions, symptoms may serve to irritate and frustrate the hostile partner—one of the few mechanisms available to the patient to “get back at” that partner. In both pathologic interactive modes, the secondary gains associated with the symptoms can further ingrain the disorder.
There is no good diagnostic instrument for OCD. The Structured Interview for DSM-IV-TR Diagnosis has only rudimentary questions regarding OCD symptoms, and good clinical judgment is required if the proper diagnosis is to be made. Psychological testing has little value in the diagnosis of OCD or in predicting treatment outcome or course of the illness.
Valid, reliable, and sensitive scales for the measurement of OCD symptom severity have been available only since the late 1980s. The best is the Yale–Brown Obsessive Compulsive Scale (YBOCS). This semistructured interview consists of three parts: a symptom checklist, a symptom hierarchy list, and the YBOCS. The rating scale evaluates severity of obsessions and compulsions on an ordinal scale from 0 to 4 (on the basis of time spent, interference, distress, resistance, and degree of control). The maximum score for this scale is 40. Patients with scores above 31 are considered to have extreme symptoms. Scores of 24–31 indicate severe symptoms, and scores of 16–23 indicate moderate symptoms. Patients with scores below 16 are considered to have mild to subclinical symptoms that often do not require treatment. The average YBOCS score for individuals with untreated OCD who are entering an OCD clinic is typically 23–25. The YBOCS also rates certain ancillary symptoms for informational purposes and provides for global assessments of severity and improvement.
Other scales that rate severity of symptoms include the Comprehensive Psychopathological Rating Scale and the obsessive–compulsive subsection of the Hopkins Symptoms Checklist-90 (SCL-90). Neither of these is sensitive to changes in symptom intensity. Both scales include measures that are highly influenced by other factors such as mood. The Clinical Global Scale and the National Institute of Mental Health global rating scale belong to another class of scales that involve clinical judgments of either global or OCD-specific illness severity or changes in severity. They are based on categories such as mild, moderate, much improved, and so on. An older group of scales (e.g., Leyton Obsessional Inventory or the Maudsley Obsessive and Compulsive Inventory) consist of lists of obsessions and compulsions, without true measures of severity.
Studies using MRI or computerized tomography (CT) have reported decreased gray matter volume either unilaterally or bilaterally in the head of the caudate nucleus. Positron emission tomography (PET) studies have found increased resting metabolic activity in the orbitomedial prefrontal cortex, especially in the right hemisphere. Increased metabolic activity has also been found in the basal ganglia, particularly in the anterior caudate nucleus. Effective treatment of OCD by either pharmacologic or behavioral means can be associated with regionally specific decreases in resting metabolic activity. This has led to the suggestion that neural circuits between the orbitomedial prefrontal cortex and the basal ganglia are hyperactive in OCD, and that treatments that modulate this activity may be effective in OCD. Imaging procedures are primarily of research interest, however, and have little diagnostic or therapeutic value at this time.
Other studies have found biochemical, neuroendocrine, and physiologic alterations associated with the neurotransmitter serotonin. Again, no clinically useful tests have resulted from this work. Finally, neurologic soft signs, eye-tracking results, and electroencephalogram (EEG) measurements have sometimes been found to be abnormal in patients with OCD. These observations have little clinical value, although the severity of soft signs may correlate with the severity of OCD.
Differential Diagnosis of Obsessions & Compulsions
The differential diagnosis of OCD is one of the most complex in psychiatry because of confusion over the meanings of the terms “obsessions” and “compulsions,” a confusion made worse by the fact that OCPD is associated with a cognitive style and behavior unrelated to OCD. It is important to recognize cognitive and behavioral phenomena that are often confused with true obsessions and compulsions. Table 21–1 summarizes these phenomena, and they are described in more detail in the next several sections.
Cognitive Differentiations | Behavioral Differentiations |
|---|---|
Anxious ruminations and excessive worries | Impulsions |
Pathologic guilt | Meticulousness or perfectionism |
Depressive ruminations | Pathologic atonement |
Aggressive ruminations |
