Space and motion discomfort in Brazilian versus American patients with anxiety disorders

Space and motion discomfort (SMD) was studied in 38 Brazilian and 50 U.S. patients belonging to one of three diagnostic groups: (a) panic disorder with agoraphobia, (b) panic disorder without agoraphobia, and (3) other nonpanic anxiety disorders. A group of 30 U.S. normal controls was also included. SMD was assessed by the Situational Characteristics Questionnaire (SitQ), which includes two scales for SMD--the Smd1 and the Smd2, and one scale for non-space-related agoraphobic discomfort, the Ag1. The score in the Smd2 is based on the sum of Likert style items, while the scores of the Smd1 and Ag1 are based on differences between contrasting subitems. A significant diagnosis effect was observed in all scales, with the highest scores in the agoraphobia group. A country effect was found only in the Smd2. A country effect was also observed when all subitems of the Smd1 and Ag1 were added rather than subtracted, suggesting that this country bias is related to a tendency of Brazilian patients to endorse symptoms. Implications of these findings to the trans-cultural validation of rating scales are discussed.