Is OCD Hereditary? Genetics And Obsessive Compulsive Disorder

OCD is a common psychiatric disorder that presents itself in up to 2% of the global population. It is no wonder then that you may ask yourself, is OCD hereditary?

You may have a close family member who suffers from OCD – perhaps a parent or sibling – and wonder whether this makes you more vulnerable to the disorder.

Alternatively, you may have an OCD diagnosis yourself and question whether you can or can’t pass it on to your children.

To answer simply, OCD is considered a familial mental health disorder.

Conducted twin studies demonstrate that one varying factor in the onset of OCD could be genetics. At this point, it is worth stressing that we do not know definitively what causes OCD. Likewise, despite these studies showing convincing evidence that genetics may have a part to play in a person’s susceptibility to this condition… The results are not conclusive.

The two key components that keep us stuck in the OCD cycle are the fear-inducing unwanted thoughts, images, feelings, sensations, or urges (obsessions) and the mental or physical ritual-like behavior we perform to relieve the extreme anxiety caused by these obsessions (compulsions).

People without OCD also have intrusive thoughts.

Almost everyone who has a brain experiences intrusive thoughts or images at some point. 

Yet, the non-OCD sufferer can accept the uncertainty that comes along with these mental intrusions. While someone with OCD can get lost in the ‘what if’ thoughts.

• What if I don’t do A,B,C?

• What if it does mean something about me?

• What if X,Y,Z is true?

The sense of discomfort and unsafety that arises during rumination over those fearful obsessions causes great distress. And so, if you find yourself stuck in this cycle, it is understandable to want to know WHY. Especially when 97-98% of people with intrusive thoughts can seemingly move on with their day without thinking twice about them.

OCD and Genetics: The History

The first OCD diagnosis was over 100 years ago. A lot of people find themselves wondering whether OCD has become more common in modern-day society. However, the likelihood is that there is simply greater awareness.

Since its discovery, clinicians have suspected that DNA has a part to play in the onset of OCD.

Maudsley Hospital in London facilitated the first report in English Literature based on fifty cases of ‘obsessional neurosis’. It concluded that 21% of siblings and 37% of parents of those diagnosed typically suffered from similar symptoms. A Hopkins OCD family case study showed strikingly similar results.

Multiple studies have proven to offer similar results suggesting that genetics can play a significant role in the development of OCD.

One study shows a prevalence of 7% to 15% in first-degree relatives with another showing 11.7% prevalence compared to only 2.7% in those without a familial connection to the disorder.

Twin studies are always an effective and helpful way to research whether DNA may have a part to play in any one psychological disorder. DNA is identical in maternal twins compared to fraternal twins who are genetically only as similar as regular siblings.

When OCD is present, up to 80% of identical twins can both have the disorder with non-identical twins only sharing the disorder up to 50% of the time. Other studies claim that identical twins have up to 90% chance of both presenting with OCD, the statistics are quite convincing.

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NOTE: What we cannot ignore here is the environmental factors that influence us all, including identical twins.

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Identical twins brought up under different conditions and varying outside influences can be more or less vulnerable to OCD depending on those differentiating factors, genetics is not the only possible cause we should take into account.

If one were to be an athletic enthusiast and the other an online gamer, then although they ‘should’ physically be very similar, the athlete is likely to be bigger and more muscular.

What are the chances of me passing OCD on to my child?

This is a common and understandable question to have.

Whatever psychiatric condition we may be living with, parents will always want to protect their children from having to live through the same struggles they experience every day. The World Health Organization calls OCD one of the 10 most distressing conditions in the world.

If you’ve experienced this, then you already know this to be true and so it only makes sense you would want to shield your child from that.

A more recent Johns Hopkins study claims that brothers, sisters, and parents of those with diagnosed OCD are up to five times greater risk of having the condition themselves.

Yet this is a moment to reiterate – we cannot ignore environmental factors and influences.

Having OCD yourself does not guarantee that your child will also have it. Just as not having OCD doesn’t guarantee your child won’t have it. Genetical influence is just one of many factors and whilst there does appear to be a correlation, it is still not definitive.

What are possible OCD genes?

Four specific genes have been identified and associated with OCD through several studies. Final results suggest that these four specific genes are absent in those without OCD and are found in three specific parts of the brain in those with OCD – the thalamus, cortex, and striatum.

Here is a breakdown of the tests conducted:

• 608 candidate genes were tested
• 222 were proven to be present in lab mice that compulsively groomed
• 196 were found in individuals with autism who engaged in repetitive behaviors to relieve anxiety.
• 56 genes were detected in a study of canines that engaged in compulsive behaviors such as chasing their tails.

The following four genes were apparent in all cases and take us one step closer to understanding the connection between OCD and DNA.

• NRXN1 – A protein coding gene.
• HTR2A – A gene involved in the chemical regulation of the brain
• CTTNBP2 – A gene involved in neural activation and synapse formation
• REEP3 – A gene that affects neurons, how they form, and how they function

Is OCD hereditary or learned?

The underlying theme and key message of this article is that genetics count for very little without environmental influence. Although we are in a continuous process of learning and understanding the root cause of this particular condition, one thing that many professionals can agree on is that the presentation of OCD is triggered by both genetics and external factors.

Mayo Clinic suggests that OCD can even be learned.

As we grow up, we learn to walk, speak, and behave by observing the people around us and mimicking their behavior. Of course, for the most part, this is an incredibly useful function. Our ability to learn and absorb this information through our keen observational skills is what makes us so adept as a species.

Yet we can learn unhelpful behavior and thinking patterns as much as we can learn helpful ones. 

According to learning theory, a child may adopt the fears of a parent and perform the same ritual-like behaviors. For example, if a parent is overly fearful of someone breaking into their home at night, they may compulsively check the locks and feel compelled to survey their surroundings through the window. This is behavior a child could, in theory, learn through observation.

Just as a child can learn to try new things, they can also learn the behavior of avoidance.

However, do not mistake this to mean that if you have OCD your child will adopt those thinking and behavior patterns. Observational learning is just one small aspect of childhood growth and experience, not to mention, there will always be an array of people in their lives to learn from.

Different types of OCD

With these advances in the genetic field of OCD, we’re keen to know whether or not there is specific DNA that triggers a particular OCD subtype.

The underlying components of OCD are present across all subtypes: obsessions, anxiety, and compulsions. But the obsessions vary depending on the subtype, different fears are present for different individuals.

Contamination OCD is the most well-known of all subtypes, yet there are many others that do not have the same level of awareness.

Here are a handful of other common OCD subtypes:

1. Harm OCD: Obsessions are typically focused on the fear of hurting others or themselves (self-harm OCD).

2. Religious (Scrupulosity/Moral OCD): Obsessions are focused on the fears of behaving in a way that goes against their religious values

3. Pedophilia OCD: Obsessions are focused on the fear of committing sexual harm toward a child.

4. Relationship OCD: Obsessions are focused on fears that they don’t love their partner enough, that they will do something to ruin their relationship, or that their partner is lying to them or cheating on them.

5. Sexual Orientation OCD: Obsessions are focused on fears of being homosexual, heterosexual, pansexual, or other sexualities when they are in fact, the opposite (it can also challenge their gender orientation)

When we take a look at the different subtypes, this is where it becomes even more clear that DNA alone cannot possibly be the sole underlying cause of OCD. OCD is a mental illness where unwanted obsessions are not aligned with the individual’s inherent values.

It attacks what the individual knows to be true about themselves and leaves them questioning their own self-concept and identity. This is what is known as egodystonic (which is why OCD is considered an egodystonic condition).

If we then zoom in on this knowledge, it is clear that there must be different triggers for different people depending on their values.

For example, someone who grew up in a religious household may live their lives according to their religious values. When an unwanted thought or image arises to challenge that, they may be left questioning why they would think such a thing as someone who is devout in their religious beliefs.

Likewise, if someone grew up in a household where they, unfortunately, adopted negative views toward homosexuality, an unwanted urge that may arise toward someone of the same sex can then be confusing and invoke feelings of shame. Especially if the parents of this person have strong negative feelings toward homosexuality, they may fear what they think of them as well as what they think of themselves.

The reason OCD is so distressing within particular subtypes like the ones above is precisely that it attacks our values and leaves us questioning who we really are.

It is true, OCD can manifest in a way that is entirely illogical and has nothing to do with our values. Yet, with these particular subtypes, researchers are intrigued to understand whether or not there is a genetic component involved.

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Conclusion: Does OCD run in the family?

Ultimately, yes, genetics do appear to be just one of the many factors involved in the onset of OCD. But, it is likely that they only make someone more vulnerable to developing the condition and not a root cause of the condition in and of themselves.

Environmental factors must be taken into account. Where this particular condition is concerned, it could all boil down to one simple combination: a genetic predisposition and an environmental trigger.

Sharing DNA with a first-degree relative with OCD does not guarantee that you will also trigger the condition. Although there are four genes that have currently been identified as being present in OCD sufferers, OCD does not have a specific ‘OCD gene’ in and of itself.

It may be present in multiple generations of your family, but this does not ensure that you will develop this condition.