<b>Correlation between emotion and pain in patients </b><b>with dental phobia: a clinical study </b>

Abstract

Background: Patients often enter clinical situations feeling a variety of emotions. It is important to relieve these emotions because there is a negative correlation between a patient's emotions and pain. In this study, we evaluated the correlation between pain and emotions such as anxiety and depression. We also examined whether a reduction in anxiety or depression could diminish pain by using the 5-HT1A agonist tandospirone citrate as an anxiolytic agent. Subjects and methods: A total of 270 patients were enrolled in two studies. These included 250 patients with dental phobia in Studies 1 and 2 (Study 1: 71 males, 107 females; Study 2: 33 males, 39 females), and 20 patients with no dental phobia in Study 2 only (10 males, 10 females). Anxiety was evaluated using the Spielberger State and Trait Anxiety Inventory (STAI) and depression was evaluated using the Zung Self-Rating Depression Scale (SDS). Venipuncture and cannulation were performed on the median cubital vein using a 22-gauge needle. Pain caused by the needle was measured immediately after the puncture using the Visual Analogue Scales (VAS). In Study 1, anxiety and depression were evaluated and the degree of trait anxiety, state anxiety and depression before venipuncture in the three groups was classified. We then compared these results with the VAS results in each group. In Study 2, anxiety was evaluated using the STAI measured previously (STAI-1). Subjects were divided into four groups as follows: no treatment group (NT: n=25, 11 males, 14 females); Mecobalamin group (ME: n=25, 12 males, 13 females); Tandospirone group (TA: n=22, 10 males, 12 females); and no dental phobia group (NP: n=20, 10 males, 10 females). The subjects in the ME and TA groups were given 1.5 mg of Mecobalamin or 30 mg of Tandospirone, respectively, and anxiety was examined sixty minutes after the medication was administered (STAI-2). The second evaluation was followed immediately by venipuncture, and pain caused by the needle was assessed. Results: The VAS for each group in Study 1 increased significantly with regards to degree of trait anxiety and state anxiety, but not with depression. In Study 2, there was no significant change in trait anxiety in any of the four groups. In contrast, state anxiety increased significantly in the NT group, but not in the ME, TA or NP groups. Pain caused by the needle used for venipuncture was significantly lower in the TA group, and was similar to that recorded for the NP group. Conclusions: This study demonstrates that anxiety amplifies pain in patients with dental phobia. These results suggest that the suppression of patient anxiety could also lead to the reduction of pain.