Yale Study Finds Genetic Links Behind Hair-Pulling and Skin-Picking Disorders

Trichotillomania (repeated hair-pulling) and excoriation disorder (repeated skin-picking) were the focus of a Yale study examining their potential genetic causes. Both are classified as body-focused repetitive behaviors, or BFRBs — conditions that can cause distress, shame and pain, and disrupt school, work and home life, affecting roughly 1% to 3% of people, according to the study's authors. The conditions often run in families, suggesting a genetic role, though how had been unclear.

Emily Olfson of the Yale Child Study Center, the study's corresponding author, and colleagues Samantha Greenspun and Thomas Fernandez used a family-based approach, collecting DNA from more than 100 people with a BFRB along with both of their biological parents, to ask whether certain genetic risk factors were passed down to affected children more often than expected by chance. The findings were published in Translational Psychiatry in June 2026.

The team found that a common genetic risk score linked to obsessive-compulsive disorder (OCD) was passed down to people with BFRBs more often than expected — even in those who did not also have OCD, suggesting the two conditions share some underlying biology beyond simply occurring together. Some participants with BFRBs also carried rare DNA changes called copy number variants, stretches of DNA that are missing or duplicated, some of which have previously been linked to neurodevelopmental conditions and to genes involved in how brain cells build connections.

The authors say the findings show BFRBs have a biological component and are not caused by poor parenting or a lack of willpower, though a genetic link does not mean a fixed outcome — common genetic factors, rare genetic factors and environment likely all play a role. They describe the study as a starting point, and call for larger, more diverse studies, noting that psychiatric genetics research has historically overrepresented people of European ancestry.