Constance L. Hammen tackles the importance of stress in mood disorders in chapter 4, "Stress and the Course of Unipolar and Bipolar Disorders." Studies revealed that stressors are associated with a greater risk for recurrence or relapse in bipolar disorder, even in medicated patients. Dr. Hammen emphasizes that the relationship between stressors and symptoms is influenced by a wide array of variables, both internal and external. She also argues that there are "psychological residues" contributing to the recurrence and chronicity in mood disorders. Chapter 5, "The Relationship of Stress to Panic Disorder: Cause or Effect?" by Sherry A. Falsetti et al., points out the similarities of panic disorder and posttraumatic stress disorder (PTSD) and their comorbidity. The authors also present data on the high rate of criminal victimization among patients with panic disorder. In chapter 6, "Etiological Factors in the Development of Posttraumatic Stress Disorder," J. Douglas Bremner, Steven M. Southwick, and Dennis S. Charney provide a marvelous overview of stress and PTSD, including stress factors, prestressor factors, peritraumatic factors, and poststressor factors. Chapter 7, "Stress of Bereavement and Consequent Psychiatric Illness," by Kathleen Kim and Selby Jacobs, deals with the most severe stressor. Bereavement is also an ideal model for examining the relationship among this significant stressor, mental health, and risk factors for psychiatric complications. David L. Snow and Marsha L. Kline discuss stress prevention in the final chapter, "Preventive Interventions in the Workplace to Reduce Negative Psychiatric Consequences of Work and Family Stress." They focus on two significant protective factors: social support and coping strategies, and their relationship to psychiatric outcomes.