Obsessive Compulsive Disorder

Obsessive-compulsive disorder (OCD) is a psychiatric disorder, more specifically, an anxiety disorder. OCD is manifested in a variety of forms, but is most commonly characterized by a subject's obsessive (repetitive, distressing, intrusive) thoughts and related compulsions (tasks or rituals) which attempt to neutralize the obsessions.

The phrase "obsessive-compulsive" has worked its way into the wider English lexicon, and is often used in an offhand manner to describe someone who is meticulous or absorbed in a cause. Such casual references should not be confused with obsessive-compulsive disorder. It is also important to distinguish OCD from other types of anxiety, including the routine tension and stress that appear throughout life.

Obsessions are defined by:

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 to neutralize them with some other thought or action
the person recognizes that the obsessional thoughts, impulses, or images are a product of his or her own mind

Compulsions are defined by:

repetitive behaviours or mental acts that the person feels driven to perform in response to an obsession, or according to rules that must be applied rigidly.
the behaviours or mental acts are aimed at preventing or reducing distress or preventing some dreaded event or situation; however, these behaviours or mental acts either are not connected in a realistic way with what they are designed to neutralize or prevent or are clearly excessive.

In addition to these criteria, at some point during the course of the disorder, the sufferer must realize that his/her obsessions or compulsions are unreasonable or excessive. Moreover, the obsessions or compulsions must be time consuming (taking up more than one hour per day), cause distress, or cause impairment in social, occupational, or school functioning.

Symptoms and prevalence

Modern research has revealed that OCD is much more common than previously thought. An estimated 1 in 50 adolescents and adults is thought to have OCD. Because of the condition's personal nature, and the lingering stigma that surrounds it, there may be many unaccounted-for OCD sufferers, and the actual percentages could be even higher. The typical OCD sufferer performs tasks (or compulsions) to seek relief from obsessions. To others, these tasks may appear odd and unnecessary. But for the sufferer, such tasks can feel critically important, and must be performed in particular ways to ward off dire consequences and to stop the stress from building up. Examples of these tasks: repeatedly checking that one's parked car has been locked before leaving it; turning lights on and off a set number of times before exiting a room; repeatedly washing hands at regular intervals throughout the day. Symptoms may include some, all or perhaps none of the following:

Repeated hand-washing.
Specific counting systems - i.e. counting in groups of four, arranging objects in groups of three, having objects grouped in odd/even numbered groups, etc.
- One serious symptom which stems from this is "counting" your steps, e.g. you must take twelve steps to the car in the morning, etc.
Perfectly aligning objects at complete, absolute right angles, etc. This symptom is shared with OCPD and can be confused with this condition unless it is realised that with OCPD it is mainly stress-related.
Having to "cancel-out" bad thoughts with a good thought. Examples are:
- Imagining harming a child, and having to imagine (for example) a child playing happily to "cancel" it out.
- Unwanted sexual thoughts such as fear of being gay (or straight if you are gay) and trying to ascertain whether the same sex arouses the sufferer or not with no clear cut answer or fear of being a pedophile.
Also, there are many other symptoms. It is important to remember you must be diagnosed by your doctor to lawfully suffer from OCD; furthermore if you do have any symptoms above it is not a firm sign you do not have OCD and vice-versa.

Another symptom of the disorder is fear of contamination; some sufferers may fear the presence of human body secretion such as saliva, sweat, tears or mucus, or excretions such as urine or feces. Some OCD sufferers even fear the soap they're using is contaminated.

Obsessions are thoughts and ideas that the sufferer cannot stop thinking about. Common OCD obsessions include fears of acquiring disease, getting hurt, or causing harm to someone. Obsessions are typically automatic, frequent, distressing, and difficult to control or put an end to by themselves.

Compulsions refer to actions that the person performs, usually repeatedly, in an attempt to make the obsession go away. For an OCD sufferer who obsesses about germs or contamination, for example, these compulsions often involve repeated cleansing or meticulous avoidance of trash and mess. Most of the time the actions become so regular that it is not a noticeable problem. Compulsions can be observable; washing, for instance; but they can also be mental rituals such as repeating words or phrases, or counting.

Most OCD sufferers are aware that such thoughts and behaviour are not rational but feel bound to comply with them to fend off fears of panic or dread. Because sufferers are consciously aware of this irrationality but feel helpless to push it away, untreated OCD is often regarded as one of the most vexing and frustrating of the major anxiety disorders. In an attempt to further relate the immense distress that those afflicted with this disease must bear, Barlow and Durand (2006) utilize an odd example. Strangely enough, they implore readers not to think of pink elephants. Their point lies in the assumption that many people will immediately create an image of a pink elephant in their mind even if told not to do so. The more one attempts to stop thinking of these colourful animals, the more they will succeed in generating these mental images. This phenomenon is termed: the “Thought Avoidance Paradox”, and it plagues those with OCD on a daily basis, for no matter how hard one tries to get these disturbing images and thoughts out of his/her mind, feelings of distress and anxiety inevitably prevail. Although everyone may experience unpleasant thoughts at one time or another, these are usually warranted concerns that are short-lived and fade after an adequate time period has lapsed. However, this is not generally the case for OCD sufferers. (K. Carter, PSYC 210 lecture, February 14, 2006). People who suffer from the separate and unrelated condition obsessive compulsive personality disorder are not aware of anything abnormal with them; they will readily explain why their actions are rational, and it is usually impossible to convince them otherwise. People who suffer with OCPD tend to derive pleasure from their obsessions or compulsions. Those with OCD do not derive pleasure but are ridden with anxiety. OCD is ego dystonic, meaning that the disorder is incompatible with the sufferer's self-concept. Because disorders that are ego dystonic go against an individual's perception of his/herself, they tend to cause much distress. OCPD, on the other hand, is ego syntonic--marked by the individual's acceptance that the characteristics displayed as a result of this disorder are compatible with his/her self-image. Ego syntonic disorders understandably cause no distress (K. Carter, PSYC 210 lecture, April 11, 2006). This is a significant difference between these disorders. Equally frequent, these rationalizations do not apply to the overall behaviour, but to each instance individually; for example, a person compulsively checking their front door may argue that the time taken and stress caused by one more check of the front door is considerably less than the time and stress associated with being robbed, and thus the check is the better option. In practice, after that check, the individual is still not sure, and it is still better in terms of time and stress to do one more check, and this reasoning can continue as long as necessary. Not all OCD sufferers engage in compulsive behaviour. Recent years have seen increased diagnoses of Pure Obsessional OCD, or "Pure O." This form of OCD is manifested entirely within the mind, and involves obsessive ruminations triggered by certain thoughts. These mental "snags" can be debilitating, often tying up a sufferer for hours at a time. As of 2004, headway continues to be made by specialists. It is believed by many that Pure O OCD is in fact more prevalent than other types of OCD, although it is likely the most underreported as it is not visibly apparent, and sufferers tend to suffer in silence. In this disorder, the sufferer tries to "disprove" the anxious thoughts through logic and reasoning, yet in doing so becomes further entrapped by the obsessions. "Pure O" OCD is thought to be the most difficult form of OCD to treat. Some OCD sufferers exhibit what is known as overvalued ideas. In such cases, the person with OCD will truly be uncertain whether the fears that cause them to do their compulsions are irrational or not. After some (possibly long) discussion, it is possible to convince the individual that their fears may be unfounded. It may be extra difficult to do ERP therapy on such a patient, because they may be, at least initially, unwilling to do it. OCD is different from behaviours such as gambling addiction and overeating. People with these disorders typically experience at least some pleasure from their activity; OCD sufferers do not actively want to perform their compulsive tasks, and experience no tangible pleasure in doing so. OCD is placed in the anxiety class of mental illness, but like many chronic stress disorders it can lead to clinical depression over time. The illness ranges widely in severity. The illness affects many people and it is not curable but can be treated with anti-depressants. This illness affects millions of people worldwide, and the number keeps growing.

Causes and related disorders

It was the general belief in the 14th and 15th centuries that those who experienced blasphemous, sexual, or other obsessive thoughts were possessed by the devil. Based on this reasoning, treatment involved banishing the evil from the possessed patient through exorcism (Baer, Jenike, and Minichiello, 1968). This idea is no longer widely accepted and advancements in science have allowed many disorders to be better understood in both physiological and psychological terms. However, though more is now known regarding the psychological aspect of obsessions and compulsions, the definitive cause of OCD is still unknown. In the early 1900s, Freud attributed obsessive-compulsive behaviour to unconscious conflicts which manifested as symptoms (Baer, Jenike, and Minichiello, 1968). Even more recently OCD was linked to stressors or traumas that occurred during childhood (bad parenting and family problems, being bullied, for instance). However, subsequent research into this disorder has provided evidence to support the possibility that OCD is a biological problem. There are many different theories about the cause of obsessive-compulsive disorder. Some research has discovered a type of size abnormality in different brain structures. The majority of researchers believe that there is some type of abnormality in the neurotransmitter serotonin, among other possible psychological or biological abnormalities; however, it is possible that this activity is the brain's response to OCD, and not its cause. Serotonin is thought to have a role in regulating anxiety, though it is also thought to be involved in such processes as sleep and memory function. This neurotransmitter travels from one nerve cell to the next via synapses. In order to send chemical messages, serotonin must bind to the receptor sites located on the neighbouring nerve cell. It is hypothesized that OCD sufferers may have blocked or damaged receptor sites that prevent serotonin from functioning to its full potential. This suggestion is supported by the fact that many OCD patients benefit from the use of Selective Serotonin Reuptake Inhibitors (SSRIs)—a class of antidepressant medications that allow for more serotonin to be readily available to other nerve cells. Recent research has revealed a possible genetic mutation that could be the cause of OCD. Researchers funded by the National Institutes of Health have found a mutation in the human serotonin transporter gene, hSERT, in unrelated families with OCD. Moreover, in his study of monozygotic twins, Rasmussen (1994) produced data that supported the idea that there is a “heritable factor for neurotic anxiety”. In addition, he noted that environmental factors also play a role in how these anxiety symptoms are expressed. However, various studies on this topic are still being conducted and the presence of a genetic link is not definite as of yet. Technological advancements have allowed for the possibility of brain imaging. Using tools like positron emission tomography (PET scans), it has been shown that those with OCD tend to have brain activity that differs from those who do not have this disorder (Tennen, accessed 4/14/06). This suggests that brain functioning in those with OCD may be impaired in some way. A popular explanation for OCD is that offered in the book "Brain Lock" by Jeffrey Schwartz, which suggests that OCD is caused by the part of the brain that is responsible for translating complex intentions (e.g., "I will pick up this cup") into fundamental actions (e.g., "move arm forward, rotate hand 15 degrees, etc.") failing to correctly communicate the chemical message that an action has been completed. This is perceived as a feeling of doubt and incompleteness which then leads the individual to attempt to consciously deconstruct their own prior behaviour - a process which induces anxiety in most people, even those without OCD. It has been theorized that a miscommunication between the orbital-frontal cortex, the caudate nucleus, and the thalamus may be a factor in the explanation of OCD. The orbital-frontal cortex (OFC) is the first part of the brain to notice whether or not something is amiss. When the OFC notices that something is wrong, it sends an initial “worry signal” to the thalamus. When the thalamus receives this signal, it in turn sends signals back to the OFC to interpret the worrying event. The caudate nucleus lies between the OFC and the thalamus and it prevents the initial worry signal from being sent back to the thalamus after it has already been received. However, it is suggested that in those with OCD, the caudate nucleus does not function properly, and therefore does not prevent this initial signal from recurring. This causes the thalamus to become hyperactive and creates a virtually never-ending loop of worry signals being sent back and forth between the OFC and the thalamus. The OFC responds by increasing anxiety and engaging in compulsive behaviours in an attempt to relieve this apprehension. Violence is rare among OCD sufferers, but the disorder is often debilitating and detrimental to their quality of life. It has been alleged that sufferers are generally of above-average intelligence, as the very nature of the disorder necessitates complicated thinking patterns, but this has never been supported by clinical data. People with OCD may be diagnosed with other conditions, such as Tourette syndrome, compulsive skin picking, body dysmorphic disorder and trichotillomania. It is also interesting to note that there is some research demonstrating a link between drug addiction and obsessive compulsive disorder as well. There is a higher risk of drug addiction among those with any anxiety disorder (possibly as a way of coping with the heightened levels of anxiety), but drug addiction among obsessive compulsive patients may serve as a type of compulsive behaviour and not just as a coping mechanism. Depression is also extremely prevalent among sufferers of OCD. One idea for the high depression rate among OCD populations was posited by Mineka, Watson and Clark (1998), who explained that people with OCD (or any other anxiety disorder, for that matter) may feel depressed because of an "out of control" type of feeling. There may also be a link between Autism and Asperger's and OCD. Some cases are thought to be caused at least in part by childhood streptococcal infections and are termed P.A.N.D.A.S. (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections). The streptococcal antibodies become involved in an autoimmune process. Though this idea is not set in stone, if it did prove to be true, there is cause to believe that OCD can to some very small extent be “caught” via exposure to strep throat (just as one may catch a cold). However, if OCD is caused by bacteria, this provides hope that antibiotics may eventually be utilized to treat or prevent it (Belkin, accessed 4/12/06). OCD in men at least may be partially caused by low oestrogen levels (external link about this is below).

Demographic Features of OCD

Obsessive-Compulsive Disorder tends to be slightly more common in females than in males. Moreover, females are somewhat more likely to have lifetime prevalence of this disorder than are men (2.9% versus 2.0%). In a 1980s study of 20,000 adults from New Haven, Baltimore, St. Louis, Durham, and Los Angeles, the lifetime prevalence rate of OCD for both genders was recorded at 2.5%. In regards to education, it was found that the lifetime prevalence of OCD is lower for those that have graduated high school as opposed to those who have not (1.9% versus 3.4%). As far as age is concerned, the onset of OCD usually ranges from the late teenage years until the mid-twenties in both genders, but the age of onset tends to be slightly younger in males than in females (Antony, Downie, & Swinson, 1998).

Treatment

OCD can be treated with Behavioural therapy (BT), Cognitive therapy(CT), or a combination of both known as Cognitive-Behavioural therapy (CBT), as well as with a variety of medications. Psychotherapy can also help in some cases, while not one of the leading treatments. According to the Expert Consensus Guidelines for the Treatment of Obsessive-Compulsive Disorder (Journal of Clinical Psychiatry, 1995, Vol. 54, supplement 4), the treatment of choice for most OCD is behaviour therapy or cognitive behaviour therapy. Medications can help make the treatment go faster and easier, but most experts regard BT/CBT as clearly the best choice. Medications generally do not produce as much symptom control as BT/CBT, and symptoms invariably return if the medication is ever stopped. The specific technique used in BT/CBT is called Exposure and Ritual Prevention; this involves gradually learning to tolerate the anxiety associated with not performing the ritual behaviour. At first, for example, someone might touch something only very mildly "contaminated" (such as a tissue that has been touched by another tissue that has been touched by the end of a toothpick that has touched a book that came from a "contaminated" location, such as a school.) That is the "exposure." The "ritual prevention" is not washing. Another example might be leaving the house and checking the lock only once (exposure) without going back and checking again (ritual prevention). The person fairly quickly habituates to the (formerly) anxiety-producing situation and discovers that their anxiety level has dropped considerably; they can then progress to touching something more "contaminated" or not checking the lock at all; again, without performing the ritual behavior of washing or checking.

Pharmacologic treatments include selective serotonin reuptake inhibitors (SSRIs) such as paroxetine, sertraline, fluoxetine. and fluvoxamine as well as the tricyclic antidepressants, in particular clomipramine. SSRIs prevent excess serotonin from being pumped back into the original neuron that released it. Instead, the serotonin can then bind to the receptor sites of nearby neurons and send chemical messages or signals that can help regulate the excessive anxiety that OCD patients suffer from. SSRIs seem to be the most effective drug treatments for OCD because they work well with chronic anxiety. SSRIs help about 60% of OCD patients, but relapses are common once the medication is no longer taken (Barlow & Durand, 2006). Other medications like gabapentin, lamotrigine, and the newer atypical antipsychotics such as olanzapine and risperidone have also been found to be useful as adjuncts in the treatment of OCD. Symptoms tend to return, however, once the drugs are discontinued. The naturally occurring sugar Inositol may be an effective treatment for OCD Recent research has found increasing evidence that opioids may significantly reduce OCD symptoms, though the addictive property of these drugs likely stands as an obstacle to their sanctioned approval for OCD treatment. Anecdotal reports suggest that some OCD sufferers have successfully self-medicated with opioids such as Ultram and Vicodin, though the off-label use of such painkillers is not encouraged, again because of their addictive qualities. Studies have also been done that show nutrition deficiencies may also be a probable cause for OCD and other mental disorders. Certain vitamin and mineral supplements may aid in such disorders and provide the nutrients necessary for proper mental functioning. Some individuals who experience OCD can find relief from attending 12-step support group meetings. These meetings, often under the auspices of Obsessive Compulsive Anonymous (OCA), are patterned after the system originated by Alcoholics Anonymous (AA). Meetings are customarily restricted to those who, to the best of their judgement or through a clinical diagnosis, have OCD. It is not unusual to find some attendees who may not have experienced relief through behavioural therapy or medication, but profess that "working the steps" alone has helped alleviate their symptoms. For some, neither medication, support groups nor psychological treatments are helpful in alleviating obsessive-compulsive symptoms. These patients may choose to undergo psychosurgery as a last resort. In this procedure, a surgical lesion is made in an area of the brain (the cingulate bundle). In one study, 30% of participants benefited significantly from this procedure (Barlow & Durand, 2006).

OCD in literature and film

The media's portrayal of OCD sufferers as eccentric and overtly neurotic is a contributing factor in the continuing public misconception of the disorder. Contrary to popular belief, OCD sufferers will rarely exhibit their compulsive behaviours in public, often becoming very adept at hiding or camouflaging their rituals. To the outside observer, the person with OCD will often seem completely normal. In fact, the more visible traits of OCD are actually ones that are encouraged and even admired in society, such as perfectionism, attention to detail, and cleanliness. The popular media rarely portrays sufferers as how they truly are locked in a debilitating cycle of meaningless rituals that they feel compelled to perform even while recognizing their senselessness.

Adrian Monk (played by Tony Shalhoub), the title character of the American television series Monk, is a detective whose severe OCD is alternatively beneficial and detrimental to his line of work.
Rosalie, in Takin' Over the Asylum, has an OCD about cleanliness.
In Alfred Hitchcock's Vertigo, Scottie (played by James Stewart) seems to show the OCD characteristics of inflexibility; preoccupation with details, rules, and lists; reluctance to allow others to do things; and restrictive expression of affection in the scenes when he remakes Judy (played by Kim Novak) into the dead love of his life, Madeline.
In the sitcom '[Friends, Monica Geller (played by Courteney Cox) has a severe obsession with neatness and order.
Justin Green's 1972 Binky Brown Meets the Holy Virgin Mary was based on the artist's childhood experience of what was later diagnosed as OCD. Green suffered from arranging, cleansing, and avoidance compulsions related to intrusive religious and sexual fears.
Diane Chambers (played by Shelley Long), on the television series Cheers, suffers from OCD. She admits that the pens in her pocket need to be lined up in a certain way. She also hoards stuffed animals in her apartment.
Matthew Roman (played by Matthew Lawrence), the character of Brotherly Love, is under the false impression that he has OCD; this becomes a running joke.
In Phillip Pullman's His Dark Materials trilogy, the mother of protagonist Will Parry suffers from a form of OCD, although this is actually caused by her ability to see or sense spectres. Rituals include touching all the leaves on a particular bush before leaving or counting.
In "A Plague of Tics," the second chapter of his 1997 memoir Naked, humorist David Sedaris describes the tragicomicimpact of OCD on his childhood. Sedaris' other works make passing references to the disorder.
The 1997 film As Good as It Gets starred Jack Nicholson as an obsessive-compulsive author. Nicholson received an Oscar for the performance. The film has been criticized for an exaggerated portrayal of OCD symptoms aimed mostly at getting laughs.
When the Billy Crystal character is approached by the OCD Agents to spy on his client (Robert De Niro character), in Analyze This, they had to explain to him that they worked for the Organized Crime Division.
In the book series Everworld, Jalil Sherman's OCD is particularly painful, as his mind is otherwise rigidly bound to science and logic. It also serves as the basis for his connection to Senna.
The 2000 film High Fidelity features the main character Rob Gordon's (John Cusack) obsessive categorizing of his extensive record collection. The movie features his constant making of lists like the top 5 things about missing his girlfriend or the top 5 most memorable break ups in his life.
The 2003 film Matchstick Men featured Nicolas Cage as a con artist suffering from OCD-style symptoms.
Legends of vampires and their behaviour show some symptoms of OCD.
The 2004 book by Steve Martin, The Pleasure of my Company is told from the point of view of a juvenile, but charming, mathematical genius with OCD.
The 2004 film The Aviator starred Leonardo DiCaprio as reclusive genius Howard Hughes, who was believed to have suffered from OCD
In the 2005 film Elektra, the title character (played by Jennifer Garner) is said to suffer from OCD, despite her own claims not to. The film itself makes almost no physical reference to this fact, other than a scene in which Elektra is shown to be cleaning a floor as a "compulsion" and a scene where she arranges and rearranges the objects in a house she is staying in. Also, she is seen counting her steps as she walks in two scenes. The movie was criticized by OCD-experts and sufferers for this treatment.
In the 2005 film Deuce Bigalow: European Gigolo, Deuce's girlfriend, Eva, suffers from acute obsessive-compulsive disorder. She does things like bite people when a horn is honked, smells herself when she hears sirens, slaps herself three times when someone sneezes, etc.
In the TV show Joey, Joey Tribbiani's executive producer, Lauren (played by Lucy Liu), suffers from OCD. She compulsively checks to ensure that her oven is not left on at home, and feels the need to knock upon hearing a knocking noise.
In the TV show Desperate Housewives, Bree Van De Kamp (played by Marcia Cross), suffers from OCD. She is highly sensitive about objects being in order (as well as her emotional life).
Malcolm McDowell plays an OCD sufferer in the show Shadow Realm whose rituals keep the entire universe in working order.
The character of "Cameron" in the British teen soap opera Hollyoaks has OCD, and his storylines often dealt with the difficulties surrounding the disease.
In Ken Kesey's novel One Flew Over the Cuckoo's Nest, clinic patient George Sorensen suffered from acute OCD. In the book he is described like "the water freak, who grins and shies back from that unsanitary hand" and he says things like "Those boats awful dirty any more — everything awful dirty." He behaves accordingly.
The character "Ryan Wolfe" from CSI: Miami confesses to suffering from OCD.
The character Pandora from Death Jr.has OCD and must open any box she sees.
In the 2004 British film Dirty Filthy Love, Michael Sheen plays a successful architect, whose OCD tragically ends up costing him his wife, his job and his friends.
In the comedic movie What About Bob?, the title character Bob Wiley (Bill Murray) suffers from OCD and multiple phobias.

References

Antony, M.M., F. Downie, and R.P. Swinson. “Diagnostic Issues and Epidemiology in Obsessive-Compulsive Disorder” in Obsessive-Compulsive Disorder: Theory, Research, and Treatment, eds. M.M. Antony, S. Rachman, M.A. Richter, and R.P. Swinson. New York: The Guilford Press, 1998, pp. 3-32.
Baer, L., M.A. Jenike, and W.E. Minichiello. Obsessive Compulsive Disorders: Theory and Management. Littleton, MA: PSG Publishing, 1986.
Barlow, D.H. and V. M. Durand. Essentials of Abnormal Psychology. California: Thomson Wadsworth, 2006
BBC Science and Nature: Human Body and Mind. Causes of OCD
Belkin, L. “Can You Catch Obsessive-Compulsive Disorder?” The New York Times Magazine
Carter, K. "Obsessive-Compulsive Disorder." PSYC 210 lecture: Oxford College of Emory University. Oxford, GA. 14 Feb. 2006.
Carter, K. "Obsessive-Compulsive Personality Disorder." PSYC 210 lecture: Oxford College of Emory University. Oxford, GA. 11 April 2006.
Foa, Edna B. & Wilson, Reid Stop Obsessing! How To Overcome Your Obsessions And Compulsions, Bantam Books, 1st Edition, 2001
Mineka, S., Watson, D. & Clark, L. A. (1998). "Comorbidity of Anxiety and Unipolar Mood Disorders." Annu. Rev. Psychol., 49, 377-412. Peer reviewed journal article offering a possible explanation for the high comorbidity rate of anxiety disorders and certain mood disorders.
OCD and Contamination
Quick Reference to the Diagnostic Criteria from DSM-IV-TR. Arlington, VA: American Psychiatric Association, 2000.
Rachman, Stanley & De Silva, Padmal Obsessive Compulsive Disorders: The Facts, Oxford University Press, 2nd edition (1998)
Rapoport, Judith, L. The Boy Who Couldn't Stop Washing : The Experience and Treatment of Obsessive-Compulsive Disorder (1991)
Rasmussen, S.A. “Genetic Studies of Obsessive Compulsive Disorder” in Current Insights in Obsessive Compulsive Disorder, eds. E. Hollander, J. Zohar, D. Marazziti, and B. Oliver. Chichester, England: John Wiley & Sons, 1994, pp. 105-114.
Causes of OCD Remain a Mystery

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