OCD includes two major types of symptoms: obsessions and compulsions. A person diagnosed with OCD can experience both sets of symptoms, or only one of the two.
Obsessions are thoughts, urges, or images that just won't leave a person alone. They're perceived as being intrusive and unwanted, and they often lead to feelings of anxiety, shame, and doubt. Some common obsessions include:
Compulsions are repetitive behaviors that a person performs according to a rigid set of rules, or in response to an obsession. Compulsions are intended to reduce anxiety, although they have no realistic connection to the anxiety-producing situation, or they are excessive. Some common compulsions include:
To meet the criteria for OCD, the individual must have obsessions or compulsions, or both.
A diagnosis of obsessive-compulsive disorder also requires that the obsessions and compulsions are time-consuming (for example, they require over 1 hour every day), distressing for the individual, or they cause impairment in an important area of functioning.
Finally, the symptoms of OCD cannot be better explained by another cause, such as a drug or medical condition (including other mental disorders).
Adapted from the DSM-5 by the American Psychiatric Association
So, how does OCD actually work? First, to understand OCD, you need to know a little bit about anxiety. Your body uses anxiety as an alarm system to warn you about possible dangers. At a low level of perceived danger, your body might experience stress. At a high level of perceived danger, your body will experience fear. Normally, anxiety helps to keep us alive. It stops us from driving far too fast, and it keeps us alert when we walk down a dark street alone.
With OCD, the anxiety alarm system is triggered far too easily, and its warnings are much more intense than necessary. Minor dangers—or dangers that don't even exist—might trigger a strong anxiety response.
Imagine that someone with OCD touches a doorknob, and becomes overwhelmed with the fear that their hand will become infected (this is the obsession). They immediately wash their hands, but not for 15 seconds like many people might. Instead, they wash their hands for 10 minutes (this is the compulsion).
The brain takes note of the serious response to touching a doorknob, and confirms to itself that touching doorknobs must be dangerous. Furthermore, the brain notices that the anxiety did in fact diminish after 10 minutes of hand washing, so it must have helped. This creates a negative feedback loop where small sources of anxiety result in extreme responses, which then further reinforce the obsessions and compulsions (Abramowitz, 1996.)
During the treatment of OCD, this cycle will be identified and broken. One form of treatment that focuses on the disruption of this cycle is called exposure and response prevention therapy.
Other OCD Resources
We've collected several resources related to OCD to help you continue your education:
Guided Meditation for Detachment From Over-Thinking (Anxiety / OCD / Depression) This meditation encourages a calm awareness of the breath, and also a gentle detachment from the habits of rumination (ie. over-thinking). This session is useful for alleviating symptoms of anxiety, OCD, and depression. https://www.youtube.com/watch?v=1vx8iUvfyCY
A Kid's Guide to Overcoming OCD book (affiliate link) Ctrl and click on link