Statement of Problem: Psychosomatic factors and their association with dermatological disorders are well recognized; yet, their importance in oral lichen planus (OLP) is still debated.
Purpose: This study was done to determine the importance of stress in patients with OLP.
Materials and Method: In this cross-sectional  case control study, the control group consisted  of 47 apparently healthy patients without any mucosal lesion,  and the experimental group consisted of 52  biopsy proven OLP subjects (28 erosive lichen planus and 24 reticular form) which were age and sex matched with the control group. They were referred to department of oral medicine in Tabriz University of Medical Science during May 2008-July 2008. The General Health Questionnaire-version 12 (GHQ-12) and the Perceived Stress Scale (PSS) were used to evaluate stress in OLP patients and control group.  The data were analyzed through Kruskal-Wallis and Man Whitney tests.  P value less that 0.05 was considered as significant.
Results: The patients with erosive lichen planus had significantly more stress (Z = 4.123; p < 0.05) than the controls. Similar findings were noted between the reticuler lichen planus and control group (Z = 5.891; p < 0.05). However, the differences in stress (Z = 2.248; p > 0.05)was found to be non-significant between the patients with erosive lichen planus and reticular form.
Conclusion: A significantly higher level of stress was found in the OLP patients (both erosive and reticular form) than the control group, but no significant difference was noted between the patients with erosive lichen planus and reticular form.Therefore it can be concluded that psychological stressors play an important role in the creating OLP.