This paper recounts my work with Anna, a 26-year-old married woman working in two part-time jobs, who presented with major depression. The high prevalence rates of depression, the comorbidity of depression with personality disorders (see Farmer & Nelson-Gray, 1990), and the long-term and destructive course of borderline personality disorder (BPD) present a formidable challenge both to mental health professionals and clinical researchers (A. T. Beck, Freeman, & Associates, 1990; Gunderson & Zanarini, 1987; Linehan, 1993; Ryle, Leighton, & Pollock, 1997). Two main themes will be emphasized. First, the last 10 years has seen a burgeoning of clinical accounts, theoretical expositions, and clinical research of comorbid depression and personality disorders in the cognitive-behavioral tradition. This paper seeks to draw on this literature in describing and explaining the case of Anna. Second, a developmental psychopathology cognitive-behavioral approach is adopted in conceptualization and treatment planning.