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.
Numerous intrusive or persistent mental experiences have no relation to OCD. The experiences listed in this section are often confused with obsessions but can be distinguished on the basis of careful examination.
Anxious Ruminations & Excessive Worries
Anxious ruminations and excessive worries are persistent intrusive concerns about adverse circumstances in the future. They are characterized by preparative cognitive processing designed to deal with those circumstances. They differ from obsessions in that they are realistic in their nature, although they may be excessive. Worries can be fleeting or semiconscious mental experiences associated with feelings of anxiety, whereas anxious ruminations are drawn out in time as the mind reviews potential adverse scenarios. They are not associated with rituals. In contrast to anxious ruminations, obsessions are immediate, aversive sensory experiences, often accompanied by incongruous dreadful mental images and specific unrealistic fears that those circumstances might occur or might have already occurred. While an individual may take preparatory actions in association with anxious ruminations, the experience lacks the dreadful immediacy of obsessive fears and the sense of urgency that drives the compulsive behaviors. Obsessions and worries can coexist when an obsession triggers not only an immediate sense of dread but also cognitive mental processing related to future untoward consequences of the dreaded event. Excessive worries and anxious ruminations also occur in generalized anxiety disorder and in OCPD. They are generally responsive to benzodiazepines. Obsessions, as a rule, are not.
Pathologic guilt involves a heightened experience of responsibility for misfortune or harm. The perceived responsibility is usually excessive for the circumstance and can be delusional in nature. It is almost always associated with depressed mood. It differs from an obsession in that the individual truly believes that he or she bears responsibility for an adverse circumstance and experiences excessive remorse. Patients with OCD may have fears that they are responsible for horrific circumstances but usually recognize that their fears are unrealistic. Their experience is one of dread or horror at the notion that they might have done something harmful, often accompanied by significant anxiety relating to future ramifications of such events. Except in cases of delusional OCD, patients with OCD rarely experience remorse or regret in association with their obsessions, because they recognize at some level the absurdity of their concern. Many patients with OCD do become depressed and may have both obsessive concerns and pathologic guilt. Pathologic guilt can occur in patients with low self-esteem and almost always occurs in patients with significant depression.
Depressive ruminations involve the persistent cognitive reprocessing of past memories and experiences, associated with sadness, a sense of loss, or regret. These ruminations are active, continuous mental processes, drawn out in time. The individual ponders past events and often experiences significant guilt or remorse, without dread or uncertainty. If a sense of incompletion is present, it is associated with regret that things were not done satisfactorily in the past. There is no sense of urgency that the situation must be remedied.
Aggressive ruminations are anger-related mental processes involving either past or future ego injuries. Individuals perceive rightly or wrongly that they either were or will be offended in some way, and they replay the events surrounding these circumstances over and over in their minds. Aggressive ruminations may be associated with vengeful fantasies and paranoid ideation. Ruminations may involve envisioning past events as the individual would have preferred them to have occurred. In ruminating about the future, the individual may envision an anticipated scenario in which he or she will be slighted or wronged and may envision various responses to such indignities. In some cases the individual may have difficulty escaping from the ruminative process, leading to interference in the individual's ability to function effectively. Aggressive ruminations differ from aggressive obsessions in that the former are ego-syntonic processes, associated with anger, in which the individual is cognitively involved as an active participant. By contrast, aggressive obsessions involve horrific sensory images or unrealistic fears of acting on destructive impulses, unaccompanied by feelings of anger. The individual tries to avoid these horrific images or fears by putting the thoughts out of mind or by taking steps to make sure that they do not occur. Aggressive ruminations typically occur in individuals with personality disorders (e.g., paranoid, obsessive–compulsive, or narcissistic personality disorders) and in individuals with passive–aggressive personality traits. They may also occur in certain patients with psychotic disorders.
Fantasies are mental stories that the individual entertains, extending over a period of time. Fantasies almost always have an attractive component; however, the individual usually realizes that imagined events are unlikely to occur. In pathologic cases, the individual feels locked into the fantasies, envisioning complicated sequences of events, and is unable to withdraw from the mental experience. This may result in mental absences, delays, or impaired performance. Erotic, angry, persecutory, or paranoid fantasies should not be confused with sexual, violent, or aggressive obsessions. Erotic fantasies are associated with a sense of pleasure or captivation and are not experienced as horrific and aversive. Paranoid and anger-related fantasies involve escalating vengeful interactions with an imagined adversary and are not accompanied by doubt, dread, or uncertainty that the acts have occurred in reality. Unlike obsessions, fantasies do not drive the individual to carry out compulsions in the real world. Excessive fantasies can occur in patients with cluster A personality disorders or with OCPD.
Paranoid fears are concerns that somebody else harbors malevolent intent toward the affected individual. They may be associated with anger and may lead to avoidant, preparatory, or violent preemptive measures, designed to protect the individual from attack. Preventive measures are taken in order to prepare for or protect against attack, not to alleviate the circumstances causing the fear. Patients with OCD sometimes have fears of being harmed by others, as in fears of being poisoned; however, these patients fear that they may be random victims and not specific targets of someone harboring malevolence against them in particular. Violent acts do not occur as a primary consequence of the obsessions of uncomplicated OCD.
Flashbacks are intense, intrusive experiences associated with memories of past traumatic events. The individual usually reexperiences these events in association with a related trigger. Flashbacks often occupy the individual's entire awareness, as though the individual were reliving these events in the here and now. They differ from obsessions in that they spring from memories of past experiences and not from inexplicable horrific images unrelated to previous experience. During the flashback, the individual behaves appropriately within the context of the flashback. The individual may not be aware that the behavior is inappropriate in the present time. In some circumstances traumatic events can lead to time-consuming rituals that are excessive or unrealistic in relation to the degree of psychological trauma. Such rituals should be considered compulsions.
Pathologic attraction occurs as cognitive and visceral experiences draw an individual toward a maladaptive behavior. It can be associated with feelings of desire, longing, yearning, or a need for the release of tension. It is usually accompanied by an urge to satisfy or gratify that desire. Pathologic attraction differs from an obsession in that the latter is by nature an intensely aversive experience and triggers behavior based on escape rather than gratification. Pathologic attraction is often associated with impulsions (see “Behavioral Differentiations” section later in this chapter) and is generally present in patients with impulse-control disorders.
Rigid thinking occurs when an individual is unable to switch sets and adopt a new perspective. It is usually ego-syntonic and may be delusional in nature. People with rigid thinking may be argumentative, repeat themselves, or return to the same point again and again. They are generally unable to adopt the perspective of another individual and cannot be dissuaded from their point of view. Rigid thinking differs from obsessional concerns in that in the former there is no uncertainty or dread and little or no awareness of defect. Rigid thinking can occur in OCPD, in individuals with reduced intelligence, in geriatric populations, and in patients with organic and psychotic illness.
Pathologic indecision occurs when an individual is unable to make choices with potential outcomes of unknown or mixed valence. In some cases individuals become paralyzed because they cannot make any decisions. Although there can be a sense of dreadful uncertainty associated with not knowing the outcome, in OCD the sense of dread tends to motivate decisions (including the decision not to act). Pathologic indecision can be seen in the setting of depression and is common in some forms of OCPD in which the individual wants to optimize an outcome without sufficient information. Such a condition can lead to significant procrastination and delayed commitments.
Realistic Fears or Concerns
Individuals with realistic fears or concerns may simulate a picture of OCD. Individuals with a history of violence or pathologic absent-mindedness or inattention may have realistic concerns that these problems will recur and may take special steps appropriate for their own circumstances (e.g., removing dangerous weapons, checking the stove to be sure it is off) to reduce such recurrences. The clinician must establish that such fears or concerns have no realistic basis, or are clearly excessive, before diagnosing such concerns as obsessions.
Impulsions are maladaptive behaviors that an individual is attracted to or feels impelled to perform. They are associated with an urge for gratification, satisfaction, or release of tension. The individual may derive a sense of pleasure from the completion of the act. Impulsions can take the form of violent or destructive behaviors that release the tension associated with poorly controlled anger. Impulsions differ from compulsions in that in the former the individual is drawn to the act and derives inherent (not secondary) pleasure, satisfaction, gratification, or release of tension from its completion. By contrast, compulsions are performed to escape aversive circumstances or to prevent something terrible from happening. Compulsions in uncomplicated OCD never involve the willful performance of violent or harmful acts. Impulsions cross diagnostic lines in that maladaptive acts such as drug abuse, binge eating, serial homicide, sexual paraphilias, and impulse-control disorders all fall into this category on the basis of their underlying motivation. Some behaviors can have both gratifying and compulsive components, such as hot showers extended for both pleasure and a sense of incompletion. The clinician must separate impulsions from OCD symptoms.
Meticulousness or Perfectionism
Meticulousness, or perfectionism, is motivated by a positive sense of accomplishment in completing activities in the proper or optimal manner. The individual achieves a sense of satisfaction and believes that the act is beneficial or rewarding in some way. The individual often believes that others should behave in a similar manner regardless of whether their behavior affects the perfectionist. Perfectionism differs from obsessions with symmetry, exactness, or order in that the former is reinforced by favorable consequences. The ordering, arranging, and “just-right” compulsions of OCD are carried out because of a sense that something is, or will be, very wrong if they are not done. These patients with OCD are intensely disturbed by a sense of misalignment, and experience an aversive sense of incompletion while the behavior is in progress. They generally recognize the absurd and uniquely personal nature of the behavior and do not believe that others need to carry out the same behavior, unless it directly affects their own circumstances. Perfectionism is often associated with OCPD.
Pathologic atonement is motivated by guilt or fear of punishment. Individuals may regret past actions and seek to reduce their discomfort in the performance of penitent behavior. Pathologic atonement can take the form of religious rituals, self-punitive tasks, or in severe cases, self-injurious acts, such as flagellation or self-mutilation. This behavior differs from a compulsion of OCD in that the behavior is not motivated by doubt or incompletion but is willfully carried out to reduce the experience of guilt or to avoid an anticipated punishment of greater significance.
Under certain circumstances, an individual may have pathologic uncertainty as to whether the atonement was sufficiently or properly completed and will carry out the behavior repeatedly or excessively for that reason. In such cases the behavior is not driven so much by guilt as it is by the unreasonable sense that the action has not been carried out properly or completely. In such cases a diagnosis of OCD may be considered. Pathologic atonement can be observed in patients with severe depression, hyperreligiosity, severe personality disorders, or psychosis.
Repetitive Displacement Behavior
Repetitive displacement behavior is performed to escape or numb an aversive experience associated with an affective state such as depression or extreme anxiety. The process of carrying out and focusing attention on the act reduces the individual's awareness of the primary aversive condition. Repetitive displacement behavior can mimic OCD, as in cases where depressed or anxious individuals engage in repetitive cleaning or straightening to reduce their affective experience. Although repetitive and seemingly purposeless, the function of the behavior is to numb the psychic distress associated with the primary condition. In contrast to the compulsions of OCD, consequences of the behavior are relatively unimportant. Repetitive displacement behavior can be observed in avoidant, anxious, or depressed individuals and in patients with OCPD.
Perseverative behavior involves the repetition of thoughts, speech, or brief behavioral sequences. Perseverative behavior can be carried out without conscious thought or may occur because it reduces an awareness of anxiety or other aversive experiences. It may occur in response to an urge without any affective component. It differs from repeating compulsions in that it is carried out without purpose. Perseverative behavior is not performed as a corrective or preventive measure nor is it driven by a sense of incompletion.
Stereotypic behavior is a form of perseverative motor behavior that is rhythmic in nature. Typically simpler than other perseverative behavior, it may be associated with primary reward or with a reduction of awareness of anxiety or another aversive experience. Stereotypic behavior is frequently seen in the mentally retarded, in patients with organic illnesses, and in very disturbed individuals, often with schizophrenia. It also may occur in normal children.
Self-injurious behavior can occur in several psychological settings. It frequently occurs as an escape behavior to reduce the intensity of a highly aversive–affective experience. It can also occur as a pathologic–manipulative process. Finally, as mentioned earlier, it may be carried out as a self-punitive process in pathologic atonement. When carried out as an escape behavior, the individual will describe a release of tension associated with the act, particularly upon visualization of the self-injurious process. The pain or shock of the injury appears to reduce or block out the awareness of the aversive affective experience that triggers the behavior. By contrast, compulsions of uncomplicated OCD never involve direct self-harm. Self-injurious behavior is observed in patients with borderline personality disorder, severe depression, or some organic or psychotic syndromes.
Pathologic overinvolvement occurs when an individual is preoccupied with a single process or set of processes to the exclusion of others. Overinvolvement is generally ego-syntonic as the individual carries out the process upon which attention is focused. Each step of the process leads to the desire to carry out the next step. The individual experiences gratification from the process as it is occurring or upon completion, and the behavior is carried out because the individual values the achievement. The original purpose of the behavior may be lost. Overinvolvement becomes pathologic when the individual neglects or is unable to attend to more important tasks or social responsibilities. Pathologic overinvolvement differs from OCD in that the individual is attracted to the engagement and is not motivated by aversive experience. It can be prominent in patients with stimulant intoxication and hypomania and can occur in patients with OCPD.
Pathologic persistence is observed when an individual continues to pursue an endeavor or interaction despite repeated failure or rebuff. It can be associated with rigidity of thought or related to an individual's inability to accept unwanted circumstances. It is often associated with an overvaluing of a personal agenda, relative to the agendas of others. It can result in mutually irritating interactions with those around the individual. Pathologic persistence is goal-directed, and although there may be a concomitant sense of incompleteness or unfinished business, the behavior is motivated by some other purpose, such as a desire to win, have one's own way, or accomplish one's goals. Pathologic persistence differs from OCD in that the former behavior is ego-syntonic. The individual seeks a favorable resolution of his or her pursuits and is not trying to escape an experience of dread or uncertainty. Pathologic persistence occurs in patients with OCPD, narcissistic personality disorder, borderline personality disorder, and hypomania; and in some cases of stimulant intoxication.
Hoarding is observed in numerous syndromes other than OCD. These include anorexia nervosa, Tourette syndrome, autism, Prader–Willi syndrome, OCPD, stimulant abuse, schizotypal personality disorder, and schizophrenia. In Prader–Willi syndrome, anorexia nervosa, and some cases of autism, hoarding occurs in secrecy. These patients have hidden stashes of items that they have collected, often by stealing or other surreptitious means. Collected items may have little tangible importance to the individual, as in food collected by the anorexic individual that will never be eaten. Collecting in OCPD is performed because of a sense that items may have positive value at some point in the future. The accumulation of possessions itself is important. The possessions are an extension of the individual, and the individual feels a sense of loss or waste if called upon to discard them. In OCD, by contrast, collecting is motivated by one of two different processes. It may be associated with an unreasonable urge to obtain an item, without any underlying reason (e.g., picking up bird feathers or empty bottles on the street). Such collecting can be indistinguishable from that seen in Tourette syndrome, autism, schizophrenia, and schizotypal personality disorder. The diagnosis is made on the basis of other associated pathology. Alternatively, hoarding or collecting in OCD may be associated with an unreasonable concern that the item, although unimportant now, might be needed in the future. The patient with OCD has a sense that there may be a time when not having the item will result in a distressing circumstance that should be protected against.
Complex tics occur in the setting of a tic disorder and are usually motivated by unwanted urges without rational motivation. Although some complex tics are confined to localized muscle groups, others can mimic the compulsions of OCD. Most often these latter tics involve “just-right” perceptions, accompanied by urges to order, align, or arrange. In addition, patients with Tourette syndrome can have obsessions associated with their tics, such that they fear something terrible will happen if they do not give in to the urge to tic. These tics can be indistinguishable from the compulsive behavior of OCD. In such cases it is best to classify the behavior as both a tic and a compulsion (an OCD–tic). Because treatment decisions can be affected by the presence of tics, the clinician should always observe the patient for such processes and should ask the patient about distinctive habits or mannerisms they might have or might have had previously, particularly in childhood.
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