Two disorders with big names—trichotillomania (repeated hair-pulling) and excoriation disorder (repeated skin-picking)—were the focus of a recent Yale study looking at potential genetic causes. The two disorders are part of a group called body-focused repetitive behaviors, or BFRBs.

These are more than “bad habits”—they can cause distress, shame, and pain. They can also disrupt life at school, work, and home. According to the study's authors, roughly 1–3% of people are affected by these BFRBs. These conditions often run in families, suggesting that genes may play a role—but exactly how hasn’t been clear.

Emily Olfson, MD, PhD, assistant professor at Yale Child Study Center, is the corresponding author of the study published in Translational Psychiatry, which was designed to clarify what kinds of genetic factors might contribute to BFRBs.

The study also examined whether BFRBs share genetic risk with obsessive-compulsive disorder (OCD). Hair-pulling and skin-picking are grouped with obsessive-compulsive related disorders because they share symptoms and often occur together.

Olfson and study co-authors Samantha Greenspun and Thomas Fernandez, MD, described their study in a blog post for the research community.

They used a family-based approach called parent–child trios. This means they collected DNA from a child (or adult offspring) with one of the disorders and both biological parents. Then they asked: Are certain genetic risk factors passed down to affected offspring more often than expected by chance?

More than 100 families participated in the study. Participants were recruited in several ways, including through The TLC Foundation for BFRB community, clinics, online outreach, and previous study participants.

“These recruitment efforts allowed us to meet many families affected by these conditions,” the authors note. They add, “Talking with these families reinforced our commitment to better understand the causes of these understudied and often difficult-to-treat BFRBs.”

Common genetic risk linked to OCD was “over-transmitted” to people with BFRBs

The study found that people with BFRBs were more likely than expected to inherit something called a higher OCD polygenic score from their parents. The authors clarify that this is not a “BFRB gene.” It’s a single number that summarizes the tiny effects of many common genetic differences, each nudging risk a little. This “extra” inheritance of OCD-related genetic risk showed up even when the person with BFRBs did not also have OCD. In other words, shared biology may exist beyond just having both diagnoses.

Some people with BFRBs had rare DNA changes previously linked to neurodevelopmental conditions

They also identified something unusual in some people with BFRBs—rare copy number variants (CNVs). These are stretches of DNA that are missing or duplicated. Some of these CNVs have been seen before in neurodevelopmental conditions. Several affected genes also relate to how brain cells form connections. The authors note that some genes involved “help neurons build and organize their connections.” This aligns with broader evidence that synapse-related biology may matter in these behaviors.

For families of children and teens dealing with trichotillomania or excoriation disorder, it’s important to remember that these are real, impairing health conditions. It’s also now clear that there is a biological component. Research is starting to map out what that biology may look like.

In short, the conditions and behaviors can have inherited risk—without being anyone’s fault. They are not caused by poor parenting or lack of willpower. It is also important to note that a genetic link does not equate to destiny. The study authors stress that these conditions likely reflect a mix of influences, including common genetic factors, rare genetic factors, and environment.

The authors consider this study a starting point, not the final answer. The findings may help families by:

• Reducing blame and shame: The findings support that BFRBs aren’t simply “attention-seeking,” laziness, or bad parenting. Biology can influence risk.

• Explaining why kids can’t “just stop”: If many small genetic factors (and sometimes rare ones) influence risk, willpower alone is rarely enough.

• Supporting appropriate care early: Even though this is genetics research (not a new treatment yet), it strengthens the case that these are legitimate disorders deserving evidence-based support.

The authors argue that larger studies are needed. Future research should combine DNA sequencing, careful clinical assessments, and long-term follow-up. This may help clarify causes and (eventually) guide better treatments. They also highlight issues related to representation. Broader recruitment is essential since psychiatric genetics has historically overrepresented people of European ancestry.

Finally, the authors center the role of participating families, noting, “This research would not have been possible without the families affected by trichotillomania and excoriation disorder who generously shared their time and experiences.”