 Association splitting is a new cognitive technique which aims at reducing obsessive thoughts. It draws upon the so-called fan effect of associative priming. Transposing this principle to the treatment of obsessive-compulsive disorder OCD, we hypothesized that the sprouting of new and the strengthening of existing neutral associations to core OCD cognitions will reduce their fear-evoking properties by depriving the chain of OCD-related cognitions of associative strength. Patients with OCD are randomly allocated to either associations splitting AS or cognitive remediation CogPack training. Blind to treatment assignment, both groups are assessed before intervention and eight weeks as well as six months later with the Yale-Brown Obsessive Compulsive Scale Y-BOCS, the Obsessive-Compulsive Inventory OCI-R and cognitive tests. OCD severity derived from the Y-BOCS and the OCI-R serves as the main outcome parameters. We also explore if AS changes the OCD-related semantic networks with cognitive tasks. It is assumed that association splitting will improve OCD severity to a greater extent than CogPack training. 