Health and Disease

What OCD Really Entails

Many of us have all too often heard phrases along the lines of, “this is making me feel OCD” or “I’m so OCD about this thing,” but what is OCD really? Is it as simple as being particular about the arrangement of objects in a given space or the order of colours and letters, or is it much more of a severe, and potentially life changing condition that affects how many individuals function in their daily lives…

By Nara Ito

Published 4:50 PM EST, Sat May 22, 2021


The DSM system recognizes OCD, or Obsessive-compulsive disorder, and a range of related disorders as characterized by either obsessions (recurring thoughts and images), or compulsions (repetitive actions). Most with a diagnosis of OCD have both obsessions and compulsions.


A behavioural characteristic of OCD is compulsive behaviour.

Compulsions are repetitive

Sufferers of OCD feel compelled to repeat a certain behaviour. For example, excessive hand washing; what seems like a simple action that particularly amidst the current COVID-19 pandemic we’ve encouraged to do more, can affect sufferers of OCD by which they wash their hands to the extent it causes damage. Other common compulsive repetitions include counting, praying and tidying/ordering groups of objects.

Compulsions reduce anxiety

Around 10% of sufferers of OCD show compulsive behaviour alone – they have no obsessions, just a general sense of irrational anxiety. For the vast majority, however, compulsions are used to manage the anxiety produced by obsessions. For example, linking to the previous example compulsive hand washing is carried out as a response to an obsessive fear of germs.


Another behavioural aspect of OCD is that sufferers of OCD tend to try to manage their OCD by avoiding situations that trigger anxiety. For example, sufferers who wash compulsively may avoid coming into contact with germs. However, this avoidance can lead people to avoid very ordinary situations, such as emptying their rubbish bins. These actions end up interfering with their lives and prevent them from leading a normal life. 


For around 90% of OCD sufferers, the major cognitive feature of their condition is obsessive thoughts. Though heavily varying between individuals, obsessive thoughts are intrusive and unpleasant. Some sufferers may respond by adopting cognitive coping strategies. For example, a religious person tormented by obsessive guilt may respond by praying or meditating.

Insight into excessive anxiety  

Sufferers of OCD are aware that their obsessions and compulsions are not rational. In fact this is necessary for a diagnosis of OCD. OCD sufferers experience catastrophic and intrusive thoughts about the worst scenarios and also tend to be hypervigilant, focusing on potential hazards. 


OCD causes severe emotional arousal swell as distress due to the anxiety that accompanies both obsessions and compulsions.  It is also often accompanied by depression, so anxiety can be accompanied by low mood and lack of enjoyment in activities and irrational guilt over minor issues

Genetic explanation of OCD

OCD is an example of a condition that is presently largely understood as biological in nature.

OCD has been found to be polygenic, whereby multiple genes are involved in vulnerability to OCD; Taylor (2013) suggested ~230 different genes can be linked to the onset of OCD. Lewis (1936) observed that of his OCD patients 37% had parents with OCD and 21% had siblings with OCD, suggesting that OCD can run in families, but rather provides genetic vulnerability to OCD rather than causality. The diathesis-stress model suggests that the presence of certain genes make people more likely and vulnerable to suffer a mental disorder. However, environmental stress is also necessary to trigger the condition. 

Certain genes, which create vulnerability for OCD, called candidate genes have been identified, including the gene 5HT1-D beta. This gene has been found to affect the efficiency of transport of serotonin across synapses. 

Neural explanation of OCD

The genes associated with OCD are likely to affect the levels of key neurotransmitters as well as structures of the brain are called neural explanations. 


The neurotransmitter serotonin is known to regulate mood. Neurotransmitters are chemicals responsible for relaying information from one neuron to another. Some cases of OCD may be explained by a reduction in the functioning of the serotonin system in the brain, and some other  cases of OCD, and in particular hoarding disorder, seem to be associated with impaired decision making. 

Treating OCD with Drug Therapy

Selective serotonin reuptake inhibitors (SSRI) are the standard class of drugs used to treat OCD. They work on the serotonin system in the brain, by preventing the re-absorption and breakdown of serotonin, increasing its levels in the synapse and continuing to stimulate the postsynaptic neuron.

It takes three to four months of daily use for SSRIs to have much impact on symptoms. 

Drugs are often used alongside cognitive behaviour therapy (CBT) to treat OCD. The drugs reduce a patient’s emotional symptoms, such as feeling anxious or depressed. This means that patients can engage more effectively with the CBT. 

In practice some people respond best to CBT alone whilst others benefit more from drugs like Fluoxetine. Occasionally other drugs are prescribed alongside SSRIs. 

Whereby patients do not respond to SSRIs, a second line of defence can be other drugs such as:

  • Tricyclics (an older version of antidepressant) have the same effect on the serotonin system as SSRIs. Tricyclics like clomipramine have more severe side effects than SSRIs thus are generally kept in reserve.
  • SNRIs (serotonin-noradrenaline reuptake inhibitors) increase levels of serotonin as well as another different neurotransmitter – noradrenaline.

Nara Ito, Youth Medical Journal 2021


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By Nara Ito

Nara Ito is a student from London, England. She is interested in neurology, immunology, and genetics

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