Woods D, Laura E, Christopher B, Michael T, Stephen S, Scott C, Flint E, Angela N, Jennifer A, Michael W, Shawn C, Thilo D, Martin F, (2022) Acceptance-enhanced behavior therapy for trichotillomania in adults: A randomized clinical trial, Behavior Research and Therapy, 158, 1-8.
The two different treatment methods used in this study are Acceptance-Enhanced Behavior Therapy for Trichotillomania (AEBT-TTM) and Psychoeducation and Supportive Therapy (PST). AEBT-TTM: Combines Habit Reversal Training, Stimulus Control Procedures (HRT + SC), and acceptance-based therapy. PST: A combination of cognitive-behavioral therapy, education about the issue/diagnosis, and group therapy. TTM: Trichotillomania. 84 people participated in this study, 42 in each experimental group.
Hypotheses
AEBT-TTM will produce a higher response to treatment than PST. Also AEBT-TTM should decrease the severity of TTM symptoms.
Participants were people previously diagnosed with the DSM-IV definition of trichotillomania: repeatedly pulling out hair, resulting in noticable hair loss. Target hair is most commonly shoulder-up, mainly scalp hair, eyebrows, and eyelashes. There are two different types of trichotillomania: automatic and focused. Automatic hair pulling is not consciously registered, and may happen while the person is involved in another task, like studying for a test or watching TV. Focused hair pulling is known, and typically done because of texture or length difference, to relieve anxiety, or to chase a certain feeling. The study at hand lasted 12 weeks, with 10 one-hour therapeutic sessions and 3 check-ins: week 0, week 6, week 12.
Therapy details:
AEBT-TTM: Session 1-treatment overview & TTM psychoeducation. Session 2-HRT+SC begins. Sessions 3-8-Review of HRT+SC, acceptance-related therapy begins. Session 9 & 10 give a final review, and focus on avoiding relapse.
PST: Session 1-Meet & Greet. Sessions 2-10 cover TTM causes, impact on social functioning, healthy habits, etc.
Results
By week 6, only 70% of the participants in the PST group, and 54% of participants in the AEBT-TTM group, met diagnostic criteria for trichotillomania outlined in the DSM-IV, when 100% of people in both groups met the criteria before the study. This decreased further-at week 12, 49% in the PST group and 40% of the AEBT-TTM group met that criteria.
Discussion
AEBT-TTM is better than PST, as reported by those in the study, as well as the results of the study detailed above. Great reductions in DSM-IV criteria are apparent with both therapeutic methods, detailing how they were effective. The greater reduction with AEBT-TTM points to how it is a more effective form of therapy, and could be favored in future practice with patients who are diagnosed with trichotillomania. There was no significant difference in the impact on automatic vs. focused pulling, which leads researchers to consider three different types of TTM instead of two: sensory-sensative, low-awareness, & impulsive-perfectionistic. These potential new subsections of trichotillomania lead to potential further research on which type of therapy would impact one over another, and generally more research on TTM, which is very needed.
Chamberlain S, Lara M, Naomi F, Natalia C, John S, Kevin C, Ulrich M, Trevor R, Edward B, Barbara S (2018) Gray matter abnormalities in trichotillomania: morphometric magnetic resonance imaging study, The British Journal of Psychiatry, 193, 3, 216-221.
TTM has some overlap with OCD & Tourette's. Most obsessive-compusive-spectrum disorders have had whole brain studies, leading to conclusions about brain areas associated with the issue; disorders falling on that spectrum are most commonly liked to larger sections of the brain, such as disruption within a circuit, rather than a specific brain piece. So, since trichotillomania doesn't have any whole brain studies, there is a huge lack of knowledge about the disorder. This study is to look into brain matter differences between white and gray matter in people with trichotillomania, compared to people without.
18 (originally 20 but two people's brain scans were extraordinarily abnormal so the participants were asked to leave) unmedicated people with TTM vs. 19 without--validated by the DSM-IV diagnosis for TTM.
MRI scan.
Gray matter density increases were found in three regions in participants with tricho-"a mean density increase of 18% in the striatum (left putamen) and limbic system (left amygdalo-hippocampal cortex), increase of 23% in bilateral frontal regions (cingulate, supplemental motor, and superior cortices), and a mean density increase of 21% in left occipital and left parietal areas". Nothing significant regarding white matter was found.
Discussion
Unmedicated patients with trichotillomania had abnormally higher density of gray matter in the brain than the control group. These were found in the left amygdalo-hippocampal complex, and other cortical areas. An increase in gray matter has also been found in obsessive-compulsive disorder and Tourette syndrome, but not very consistently. This common neurological ground, though not entirely reliable, gives a link between TTM and OCD that was previously not backed by any neuroanatomical research.
Other studies have shown a decrease in gray matter tissue throughout adolesence, which is also TTM's peak prevalence. This lead researchers to think that maybe the increase in gray matter density in the trichotillomania patients may reflect some sort of developmental impediment. Alternatively, the increase in gray matter may have been the result of utilizing areas of the brain involved with learning habits and grooming. Other research has shown that learning and training motor skills may increase gray matter concentration in the cerebrum.
Research has shown that the striatum plays a part in habit learning and chunking information. Previous research with damaging the striatum in rats altered their hygine habits, similar to hair pulling in humans. This striatal damage is another link between TTM and OCD.
The researchers did not anticipate gray matter abnormalities regarding the amygdalo-hippocampal region, but it makes sense that that area would be abnormal in people with TTM. Emotional regulation, the amygdala's forte, is a huge factor in hair pulling--sometimes people with TTM pull because they're nervous or anxious, and pulling their hair alleviates some of that stress.
3. Neuroanatomy
Roos A, Jean-Paul F, Dan S, Christine L (2023) Structural brain network connectivity in trichotillomania (hair-pulling disorder), Brain Imaging and Behavior, 17, 395-402.
This study was done because there was a lot of prior conflicting information about whether a brain circuit was linked to TTM. Some studies linked the limbic, cerebellar, striatal, and frontal areas of the brain, but another linked no circuits to the disorder.
TTM is characterized as an Obsessive-Compulsive-Related Disorder in the DSM-V. It has been linked to connectivity issues in the cortico-striatal-thalamic-cortical circuit, which is common in OCRDs.
Discussion
Connectivity issues were found in the cortico-striatal-thalamic-cortical circuit, which was supported by past research as well. They also found problems with the somatosensory and sensorimotor networks, which may play into people with trichotillomania's over responses to external stimuli. Structural differences were found in the people with TTM in their occipital lobe regions, which could contrbute to the altered perception of details, such as out of place hair, with tricho. These disturbances within the brain may also be linked to the impulse and behavioral control, or lack thereof, that is a huge part of tricho. Another neuroanatomical structural issue that was found was abnormalities in the dorsal striatum in people diagnosed with TTM. The dorsal striatum plays a huge part in decision making, especially with habit formation and rewards.
Machado A, Girish H, Fortino S, Ali R (2005) Fracture of Subthalamic Nucleus Deep Brain Stimulation Hardware as a Result of Compulsive Manipulation: Case Report, Neurosurgery.
Looking for potential links with left-side predominant Parkinson's Disorder and TTM--both have similar symptoms to obsessive-compuplsive disorder, & researchers wanted to cover any possible comorbidities. One woman with left-side predominant Parkinson's Disorder & who had TTM went through subthalamic nucleus deep brain stimulation. After that procedure, she was left with incisions in her head. They found that she had been pulling hair around the incision on the left more than the cut on the right. Researchers concluded that there may be a link between the sidedness of Parkinson's Disease, and the hair pulling of trichotillomania. They hypothesized that, for further study, there may be a connection between the subthalamic nucleus' stimulation could've somehow provoked the hair pulling episodes.
5. Lesioning
Lachapelle JM, GE Pierard (1977) Traumatic Alopecia in Trichotillomania: a Pathogenic Interpretation of Histologic Lesions in the Pilosebaceous Unit, Journal of Cutaneous Pathology, 4, 2, 47-111
This study was done to look for specific & non-specific histologic lesions in the hair that people with trichotillomania remove. 10 people with scalp tricho were biopsied, & researchers removed scalp tissue, ensuring that they had some tissue with hair bulbs. Half of these people's hair was removed from the scalp tissue, & used for the study under a microscope. They found lesions affecting the structure of the hair follicle (part of the skin that is responsible for hair growth) in all 10 participants. Luckily, hair follicles cannot be removed, but unluckily, they take a long time to repair when damaged and may grow weaker, thinner hair in that case. 20% of the people pulled out their hair bulbs (rounded part at the very end, deep within the scalp tissue), which contain hair growth cells. They found trichomalacia (damage to hair shaft, which is the hair that we can see) in about 40% of the participants. With these participants, the hair was short, sometimes wavy or curled up. Some hair ducts, devoid of their hair, were filled with piles of keratin (what helps form outer layer of skin, also hair & nails) debris. Many of the features found in this article weren't specific to TTM. They found that looking at the hair and scalp after someone has a pulling episode is not the best way to distingusish a diagnosis.
Kubiak M (2015) Feather plucking in parrots, British Veterinary Association, 37, 2, 87-95
This paper looks at feather plucking in pet parrots and cockatoos. Between 10-15% of these birds experience feather-damaging behavior (FDB) as a result of their plucking, which relates to how people with trichotillomania experience hair loss and can experience damage to the skin of a repeated hair picking site (ex. scalp damage, hair loss, alopecia). This feather-damaging behavior ranges from too much preening (cleaning & straightening feathers with beak) to total feather removal and loss, with skin and muscle damage. This behavior can be performed by the bird to itself, but also commonly is done from one bird to another. Feather preening is normal in birds, but excessive self-preening has been linked to stress, wimilar to how TTM has been linked to stressful moments in the person's life. Excessive self-preening can be comforting to birds, which is another parallel to TTM being a tension/stress reliever at times for people.
Some potential stressors that the birds may experience to trigger feather plucking are isolation, as they typically learn preening behaviors by watching other birds, hand-rearing birds (can't communicate effectively), social frustration, incorrect cage size, incorrect cage position, permanent confinement, time spent away from owner, punishment, strong scents. Incorrectly clipping wings can cause uncomfortable ends, which will make the bird more likely to pluck them out. Similar to focused tricho where people pull their hair out because it feels wrong, has a different texture than surrounding hairs, or a length difference.
Decreased levels of serotonin and increased levels of dopamine have been found in both trichotillomania and FDB. Researchers have tried to use similar treatments on birds as they have in humans, such as SSRIs, but they haven't worked great.
7. Electrophysiology
CITE
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