The overlap between the depressive and anxiety disorders is extremely common. The introduction of the selective serotonin reuptake inhibitors (SSRIs) has, more than any other development, bridged the gap in terms of efficacy in both sets of disorders. A substantial body of data exists suggesting that the available SSRIs have substantial efficacy in anxiety symptoms co-occurring with depression. The clear utility of the SSRIs in disorders classified apart from depression is also established. Whilst panic disorder is the best studied, evidence on the efficacy of the SSRIs in disorders that previously did not attract much pharmacotherapeutic interest, such as social anxiety disorder and post-traumatic stress disorder is accumulating.