explanation of obsessive-compulsive disorder and major depressive disorder on the basis of thought-action fusion

objective: thought-action fusion (taf) refers to the tendency to assume incorrect causal relationship between one’s own thoughts and external reality, in which, thoughts and actions are treated as equivalents. this construct is present to development and maintenance of many psychological disorders. the aim of the present study was to predict obsessive-compulsive disorder (ocd) and its types, and major depressive disorder (mdd) with taf and its levels. methods: two groups, included 50 persons with ocd and mdd, respectively, were selected by convenience sampling method in private and governmental psychiatric centers in ardabil, iran. then, they responded to beck depression inventory, padua inventory and taf scale. data were analysed using multiple regressions analysis by stepwise method. results: taf or its subtypes (moral taf, likelihood-self taf and likelihood-others taf) can explain 14% of mdd variance (p < 0.01), 15% of ocd variance (p < 0.01), and 8-21% of ocd types variance (p < 0.05). moral taf had high levels in ocd and mdd. conclusion: the construct of taf is not specific factor for ocd, and it is present in mdd, too.