This study explored whether obsessive-compulsive (OC) and depressive phenomena share common cognitive personality vulnerabilities. Specifically, the study examined the relationship of OC phenomena to sociotropy, autonomy and aspects of perfectionism, which traditionally have been associated with depression. A non-clinical sample of 152 subjects, mostly undergraduate university students, completed four questionnaires. Results indicated a significant relationship between depression and OC variables, with both relating significantly to autonomy, sociotropy and socially prescribed perfectionism. Correlations between OC phenomena and these cognitive personality styles were still significant after controlling for depression. Sociotropy and socially prescribed perfectionism predicted unique OC variance. Depression also predicted unique OC variance, controlling for the cognitive personality styles. It was concluded that OC and depressive phenomena share vulnerability centred on desires for approval. It was also recognized that depression-specific processes account for some of the covariability between depression and OC phenomena. Therefore, it was suggested that treatment of obsessive-compulsive disorder may improve by attending to the reduction of depressive phenomena and to the modification of beliefs related to social-approval.