Guest Piece: What causes trichotillomania?

  Guest blogger Ariel Taylor provides us with a valuable insight into the ins and outs of the complex Body Focused Repetitive Behaviour (BFRB) trichotillomania, outlining what research has shown us and what we’ve yet to learn.


According to scientific research, it is difficult to attribute a cause to many mental health disorders because a cause is an event or condition from which something else results. Trichotillomania (informally known as “trich”), a mental health disorder characterized by compulsive hair pulling and classified in the obsessive-compulsive spectrum of disorders, is one scientists can only speculate about its origin. This article will highlight some theories supported by current research.

Many studies begin with the disclaimer, “the exact cause of trichotillomania is not known,” butspeculations exist. What scientists do know is that trichotillomania is more common when first-degree relatives have obsessive-compulsive disorder. Because it can be passed down genetically, it indicates a physical component exists. Research has yet to confirm the physical component but suggests that people with obsessions or compulsions of any kind tend to have serotonin deficiencies and disordered reward processing. This hypothesis is supported by the success of selective serotonin reuptake inhibitors by some people with trichotillomania. Not everyone experiences good results from these medications, however, so there are further explanations.

Other brain conditions offer reasons for trichotillomania. There are studies that show people with trich have structural brain abnormalities in the lenticulate as well as differences in the volume of the left putamen. The lenticulate is part of the caudate nucleus of the brain which plays a role in the way the brain learns and regulates the control of impulses between the thalamus and orbitofrontal cortex. This part of the brain is a suspect in the development of OCD because a malfunction here would limit a person’s ability to interrupt worries, obsessions, and compulsions. The left putamen is a part of the brain involved in movement and learning. Studies of Parkinson’s disease and stroke patients show that when the putamen is damaged in any way, a person will experience jerky, unpredictable, repetitive movements.If the part of a person’s brain that is in charge of stopping compulsions is faulty along with the part in charge of moderating repetitive movements, the chronic nature of trichotillomania is better explained.

There are other studies link trichotillomania to brain metabolism and reward processing. There is evidence suggesting that people with trich have high metabolic glucose rates in several parts of the brain. While this process is a mystery, metabolic disturbances in the brain are associated with other mental health disorders, dementia, Parkinson’s disease, Huntington’s disease, and Alzheimer’s disease. The brain needstheenergy to operate; therefore if the brain’s energyis disruptedin any way, it is safe to assume that brain functions would also be disrupted. The rewards processing theory suggests that those who pull hair experience a reward from it thereby creating an altered reward feedback loop associated with the behavior.

The cause of trich may be unknown, but there is research about what makes it worse. Trich is a lifelong, chronic condition that can be managed, but not cured. Many people with trich describe episodes or a cycle of worsening behaviors and no behaviors. Psychological factors such as stress and anxiety act as triggers for pulling hair which supports the theory of the inability to control an impulse during times of stress activation. For some people, the act of pulling hair serves as emotional regulation or self-soothing which supports the theory of disordered reward processing.

Scientists continue to search for the cause of trichotillomania because then pharmaceutical therapies can be created to target the cause. Until then, those with trichotillomania rely on the evidence-based therapies available that focus on increasing awareness of the behaviors and consciously changing them.


Bhandare, S.,Kotade, K.,Bhavar, S.,Bhangale, C., &Wagh, V. (2016). Trichotillomania: A hair pulling disorder. World Journal of Pharmacy and Pharmaceutical Sciences, 5(5), 596-615. doi: 10.20959/wjpps20165-6760