INTRODUCTION
People who receive a diagnosis of trichotillomania disorder are people who have lost a large part of their hair on their head, eyebrows, eyelashes, and other parts of their body due to hair pulling and ultimately seek treatment in pain and helplessness. These patients harm and suffer from themselves; however, they cannot stop their self-destructive behavior. In addition to the guilt and physical problems that these patients experience due to their self-destructive behavior, the anxiety and tension caused by the reactions of others and their awareness of this behavior cause patients with trichotillomania disorder to withdraw from social situations and relationships, ultimately leading to impulsivity in these patients. Rumination is another factor involved in obsessive behaviors, including trichotillomania disorder. Rumination is a form of repetitive thoughts that can be referred to as evaluative thoughts about the possible causes and consequences of feelings of sadness and depression. Despite having numerous physical, psychological, and social complications, trichotillomania disorder has been underdiagnosed and undertreated. One of the most important treatments that seems to be applicable to trichotillomania disorder is dialectical behavior therapy. Dialectical behavior therapy is one of the treatment methods that has applications and therapeutic purposes in the areas of suicide prevention, self-harm, and various self-harming behaviors. Considering the impact of trichotillomania disorder and its prevalence in recent years, it seems necessary to provide an appropriate treatment strategy, identify the most effective treatments, apply new psychological methods, and study the therapeutic results of these methods, which have been less studied in Iran. The present study aimed to determine the effectiveness of dialectical behavior therapy on impulsivity and rumination in patients with trichotillomania disorder.

METHODS
The present research employed a semi-experimental method, utilizing a pre-test and post-test design with a control group. The statistical population of this research included all patients with trichotillomania disorder who were referred to the specialized skin and hair treatment centers in the 2^nd and 4^th districts of Tehran (Iran) in 2022. The research sample consisted of 30 people, selected with informed consent using the convenience sampling method, and were randomly assigned to two groups, experimental (n=15) and control (n=15), using a lottery method. The subjects responded to Massachusetts General Hospital Hair Pulling, Barratt Impulsiveness, and Nolen-Hoeksema’s rumination questionnaires before and after the intervention. Dialectical behavior therapy was performed in 10 sessions of 60 min and twice a week in the experimental group, and during this period, the control group did not receive any treatment. Data analysis was performed using mean, standard deviation, and covariance analysis by employing the SPSS (version 24) software.

RESULTS
The results demonstrated that dialectical behavior therapy affected impulsivity and rumination (P<0.01). The mean ± standard deviation of the impulsivity variable in the pre-test phase decreased from 3.98±60.55 to 4.41±56.11 in the post-test phase. Moreover, the mean ± standard deviation of the rumination variable in the pre-test phase decreased from 3.83±60.72 to 3.76±56.72 in the post-test phase. Moreover, the results of the analysis of the covariance test indicated that there was a significant difference between the mean scores of impulsivity and rumination of the participants in the experimental and control groups in the post-test phase (P<0.01).

CONCLUSION
According to the results of the present study, it can be claimed that dialectical behavior therapy is actually a modification of cognitive behavioral therapy and is used in individuals who struggle with out-of-control emotions, as well as mood and emotional issues, such as depression, anxiety, anger, emotional instability, and irritability. Clinical specialists are asked to help the client understand disruptive behaviors as acquired behavior to solve the problem, and the client lacks the necessary skills to respond in a more creative way. Dialectical behavior therapy, using validation therapeutic strategies, problem-solving strategies, dialectical cognitive styles, and management strategies, has been effective in reducing rumination and the amount of unstable interpersonal behavioral patterns, such as ambivalence and emotional control problems, in patients with trichotillomania. According to the findings, dialectical behavior therapy was effective in the reduction of impulsivity and rumination in patients with trichotillomania; therefore, dialectical behavior therapy can be suggested as an appropriate intervention to reduce problems in patients with trichotillomania.
 

Ethical Considerations
Compliance with ethical guidelines
This study was approved by the Research Ethics Committee of Islamic Azad University, Sari Branch, Iran, with ethics code IR.IAU.SARI.REC.1401.240.

Funding
There is no funding support for this work.

Authors' Contributions
The authors contributed equally to the conceptualization and writing of the article. All the authors approved the content of the manuscript and agreed on all aspects of the work.

Conflict of Interest
The authors declared that there is no conflict of interest.

Acknowledgments
The authors are grateful to all the persons who provided scientific consulting in this paper.