How Do Different Types of OCD Symptoms Have Different Genetic Roots?

What you need to know

• Obsessive-compulsive disorder (OCD) manifests in different symptom types or “dimensions,” including aggressive/checking behaviors, contamination fears/cleaning, symmetry/ordering, hoarding, and sexual/religious obsessions
• This study found that different genetic patterns are associated with each symptom dimension
• Understanding these genetic differences could help develop more targeted treatments based on a person’s specific OCD symptoms

Understanding Different Types of OCD

OCD affects 2-3% of the population and can manifest in several different ways. Rather than being a uniform condition, research shows that OCD has distinct symptom dimensions:

• Aggressive/checking: Intrusive thoughts about harm and repeated checking behaviors
• Contamination/cleaning: Fear of germs and excessive washing
• Symmetry/ordering: Need for items to be arranged in particular ways
• Hoarding: Difficulty discarding possessions
• Sexual/religious: Unwanted thoughts related to sex or religion

These different symptom types often require different treatment approaches and can have varying responses to medications. Understanding their distinct biological bases could help improve treatment.

Key Genetic Findings

Hoarding Symptoms

The study found a significant link between hoarding symptoms and a gene called SETD3, which is active in brain regions previously connected to OCD. This gene helps regulate how other genes are expressed and is involved in cell death processes. The findings suggest hoarding behaviors may have a strong genetic component involving rare genetic variants.

Aggressive Symptoms

Aggressive checking behaviors were linked to a gene called CPE, which helps produce brain chemicals (neurotransmitters) and supports nerve cell health. The researchers also found that genes involved in how the body processes zinc and fats were important for aggressive symptoms. Zinc plays a crucial role in brain cell communication and has been linked to various psychiatric conditions.

Order and Symmetry Symptoms

For ordering and symmetry symptoms, the study found associations with genes involved in fat metabolism and signaling in the brain. Problems with fat metabolism have been connected to various mental health conditions, including bipolar disorder and depression.

Practical Implications

This research suggests that different OCD symptoms may need different treatment approaches because they have distinct genetic foundations. For example:

• Patients with hoarding symptoms might benefit from treatments targeting cell death processes or gene regulation
• Those with aggressive symptoms could potentially benefit from treatments involving zinc supplementation or targeting fat metabolism
• Symmetry/ordering symptoms might respond to treatments affecting fat processing in the brain

Conclusions

• OCD is more complex than previously thought, with different symptom types having distinct genetic patterns
• Future treatments might be more effective if tailored to a patient’s specific symptom profile
• More research is needed with larger groups of patients to confirm these findings and develop targeted treatments