1. Sierra Pacific Mental Illness Research, Education, and Clinical Center at VA Palo Alto Health Care System , Palo Alto, California , USA
2. Department of Psychology, Palo Alto University , Palo Alto, California , USA
3. Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine , Stanford, California , USA
4. Veterans Administration Rehabilitation Research & Development Service, VA Palo Alto Health Care System, Palo Alto, California, USA
5. Department of Cardiovascular Medicine, Stanford University School of Medicine , Stanford, California , USA