Obsessive-Compulsive Disorder: Overview

Obsessive-Compulsive Disorder: Overview
— Leslie E. Packer, PhD


Obsessive-Compulsive Disorder (OCD) has two main elements to it: thoughts (obsessions) and behaviors (compulsions). The hallmark of OCD is the “over and over again” quality of the repeated intrusive thoughts or rituals.

Obsessions are recurrent and persistent thoughts, impulses, or images that are experienced as unwanted, intrusive, and inappropriate. These thoughts cause marked anxiety or distress, and are not simply excessive worries about real-life problems.

Compulsions are repetitive behaviors or mental acts that the person feels driven to perform in response to an obsession, or according to rules that must be applied rigidly. These behaviors or mental acts are usually aimed at preventing or reducing distress or preventing some dreaded event or situation. Importantly, the compulsive behaviors are generally not connected to the worrying thought. For example, a child may be plagued with an obsessive worry that if they don’t turn the light switch on and off perfectly exactly 32 times, he will come home to find his dog slashed and mutilated.

In young children, we often find that the very young child does not realize that others are not experiencing the same bizarre intrusive thoughts that they are. As the child gets older and realizes how bizarre the thoughts are, they may be reluctant to tell others what’s going on internally or why they feel the need to do peculiar things.


Certain themes tend to occur across all races, cultures, and societies. The following themes are some of the more common types of intrusive, repetitive thoughts:

  1. Contamination fears (fear of germs, dirt, chemicals). This is one of the most common symptoms in terms of lifetime prevalence. Individuals may be morbidly afraid of getting AIDS or other infections, may be afraid to touch bathroom faucets, and may appear horribly anxious if anyone touches their food.
  2. Doubting. Anyone can doubt whether they remembered to turn off the coffee pot or lock the door, but someone with OCD may repeatedly doubt themselves, even after checking. It is as if they don’t trust their memory: “Did I really do that or did I just think about doing it?”
  3. Specific order or symmetry. Individuals with OCD may have a need to have things lined up or arranged in a particular way. The symmetry is also known as “evening up.”
  4. “Just so” feelings or “just right.” Individuals with OCD may need to have things “perfect” or “just right.”
  5. Aggressive or horrific imagery. Individuals with OCD may have intrusive thoughts that harm will come to a family member or others or themselves.
  6. Sexual or “taboo” imagery. Individuals with OCD may be burdened with recurring thoughts of socially unacceptable behavior.
  7. Moral and religious themes or “scrupulosity.”

Although children and adolescents with OCD also experience these same types of intrusive thoughts, they are also likely to have recurring thoughts about particular numbers – either lucky/magical or unlucky.


If you think, for a moment, about the common obsessional themes listed in the previous section, you can probably anticipate most of the common compulsive rituals or behaviors that the individual engages in “over and over again:”

  1. Washing or hygiene rituals.
  2. Counting may be combined with other compulsions. Counting is frequently a “silent ritual.” Teachers may not realize that the student is having to mentally count things while attempting to process or complete work. Since doubting also goes along with OCD, the student may suddenly begin to doubt whether they’ve counted correctly, and may have to start all over again.
  3. Checking and re-checking. Individuals who have OCD will check and recheck excessively, whether it is checking to see if they locked the door, turned off the stove or tap, or checking to see if they just ran over someone. It is not uncommon to find patients late for school or work because they spend excessive time checking and rechecking in the home. Assignments may not be submitted on time because the individual is compulsively checking and rechecking their work.
  4. Saving or hoarding.
  5. Seeking reassurance.
  6. Ordering or arranging things.
  7. Reworking something until it is “perfect.” Children who have perfectionist compulsions in school may have to erase and rework their work until there are holes in it from so much reworking. Perfectionism may also result in the child staying up until all hours of the night getting their homework perfect.
  8. Praying, tattling. Some individuals will engage in repeated prayer as a form of penance or to ward off frightening thoughts. Children who have scrupulosity obsessions may feel compelled to speak up when someone has been wronged or falsely accused. Or they may become the class “snitch” because of a need to confess or tell someone what someone else has done.
  9. Repeating compulsions. One example is the child who has to read a line backwards after reading it forwards to prevent something terrible from happening. Or the child may have to walk up and down the hall a certain number of times or come through a doorway a particular way a specific number of times. Such compulsions often combine other compulsions such as counting/numbers.
  10. Compulsive avoidance. When a particular setting or situation has become associated with compulsive behavior, the individual may start to avoid that situation or setting, for fear that they will lose control and get “stuck” performing the ritual. In other cases, some particular event or stimulus may be associated with horrific thoughts, and the individual will attempt to avoid that stimulus. Children who have gotten “stuck” engaging in a ritual in the gym, for example, may seem reluctant to go to gym the next time it is scheduled and may start offering excuses as to why they can’t go.


It has been estimated that 1% of children and up to 4% of adolescents have OCD. In children, OCD appears to be more prevalent in boys, but in adulthood, the ratio of males to females is approximately the same. The age of onset is typically reported as 6 – 15 for males and 20 – 29 for females, but we know that many children (including girls) who have Tourette’s Syndrome also have childhood-onset OCD. Other research suggests that OCD may have a bimodal (two peaks) distribution of onset. About 1/3 to 1/2 of adult patients who have OCD report that the onset was in childhood or adolescence, before age 10. Those adults who had early onset experienced more sensory phenomena and had a higher rate of tic disorders than those with later-onset OCD (see the Tourette’s overview for a discussion of sensory phenomena and tics).

In terms of long-term outcomes, Soke and Soke (1999) provided a 40 year follow-up on OCD patients. They reported that over 80% of all patients experienced improvement. Almost 50% of the sample had OCD for more than 30 years. The best predictors of both obsessive and compulsive symptoms were early age of onset, low social functioning at baseline, and a chronic course at the examinations conducted between 1954 and 1956. Magical obsessions and compulsive rituals were also correlated with a worse prognosis. In the past few years, several studies have been published that specifically look at age of onset. For a variety of measures and despite differences in methodologies and samples, early-onset OCD seems to be associated with a more severe course or worse outcome. Earlier age of onset also predicts an increased risk for Attention Deficit Hyperactivity Disorder, simple phobia, agoraphobia (fear of outdoor or public places) and multiple anxiety disorders. Mood disorders such as depression or Bipolar Disorder were not predicted by age of onset but were correlated with chronological age: older children and teens with OCD exhibited more depression and/or Bipolar Disorder than younger children.


Obsessive-Compulsive Disorder (OCD) is often referred to as “the Doubting Disease.” As with Tourette’s Syndrome, a lot of the most troubling or interfering symptoms associated with OCD are the hidden ones — the intrusive, repetitive, often disturbing thoughts called “obsessions,” although the ritualized behaviors (“compulsions”) that the person engages in may take up hours of their time every day or cause them significant distress. Intrusive thoughts can distract a student from concentrating on class work or interfere with retrieval of learning information or skills. Compulsive rituals can consume time, interfere with work or test completion, and/or lead to peer teasing or rejection.

In a study of children with OCD, the children and their parents were both interviewed about the impact of OCD on school functioning, home functioning, and social/community functioning. A significant percentage of children and parents that the biggest impact of OCD was on: (1) concentrating in class and (2) concentrating on (and completing) homework.