Eight patients with depersonalization disorder or with depersonalization symptoms in association with obsessive-compulsive and panic disorders were treated with serotonin reuptake blockers. There was clinical overlap of depersonalization disorder with obsessive-compulsive disorder, and the co-occurrence of obsessive-compulsive and panic features with depersonalization in these patients was associated with a favorable treatment outcome. The chronicity of illness and lack of prior response to a variety of treatments in these patients highlights the positive outcome with this treatment. In addition, issues are raised regarding the current hierarchical exclusion of depersonalization disorder in the presence of obsessive-compulsive and panic disorders.