William S. Kremen, Ph.D. 



Contact Information

9500 Gilman Drive
La Jolla, CA 92093-0603
T: (858) 822-2393
F: (858) 822-5856


Dr. Kremen received his Ph.D. in Clinical Psychology from Boston University in 1990. He was faculty member at Harvard Medical School and UC Davis before joining the faculty at UCSD in 2003. He is Director of the Twin Research Laboratory in the Department’s Center for Behavioral Genomic, a faculty member of the Stein Institute for Research on Aging and the San Diego State/UCSD Joint Doctoral Program in Clinical Psychology, and a scientific member of the VA San Diego Center of Excellence for Stress and Mental Health (CESAMH). He oversees the Vietnam Era Twin Study of Aging (VETSA) projects, wave 1 of which is a publicly available research resource consisting of neuropsychological, biomedical, and neuroimaging data.

Research Interests

Research Focus

Dr. Kremen’s primary current research focus is on behavioral genetic/twin studies of cognition and aging. He has led the Vietnam Era Twin Study of Aging (VETSA) projects since 2003. Wave 3 of the longitudinal VETSA project begins in 2015. There are two major goals of these projects: 1) early identification of risk for mild cognitive impairment (MCI) and Alzheimer’s disease, including the search for novel biomarkers; and 2) elucidating the heterogeneity of aging trajectories. This work involves examination of genetic and environmental influences on the interplay among cognitive, brain, biomedical, and psychosocial factors. Genome-wide genotyping and epigenetics are also integrated into traditional twin designs. Twin studies also make it possible to conduct cotwin-control designs, which provide an ideal case-control study.

Dr. Kremen’s other research interest is behavioral genetic studies of psychiatric disorders, primarily posttraumatic stress disorder (PTSD) and schizophrenia. As part of the CESAMH, he studies outcomes of PTSD over periods of 30-40 years from a behavior genetics perspective. He also collaborates on studies of gene expression in PTSD and schizophrenia.


  • Lyons MJ, York TP, Franz CE, Grant MD, Eaves LJ, Jacobson KC, Schaie KW, Panizzon MS, Boake C, Xian H, Toomey R, Eisen SA, Kremen WS. Genes determine stability and the environment determines change in cognitive ability during 35 years of adulthood. Psychol. Sci. 2009;20:1146-1152.
  • Panizzon MS, Fennema-Notestine C, Eyler LT, Jernigan TL, Prom-Wormley E, Neale MC, Jacobson KC, Lyons MJ, Grant MD, Franz CE, Xian H, Tsuang MT, Fischl B, Seidman LJ, Dale AM, Kremen WS. Distinct genetic influences on cortical surface area and cortical thickness. Cereb. Cortex. 2009;19:2728-2735.
  • Rimol LM, Agartz I, Djurovic S, Brown AA, Roddey JC, Kähler AK, Mattingsdal M, Athanasiu L, Joyner AH, Schork NJ, Halgren E, Sunder K, Melle I, Dale AM, Andreassen OA, Initiative. AsDN. Sex-dependent association of common variants of microcephaly genes with brain structure. Proceedings of the National Academy of Sciences U.S.A. 2010;108:384-388.
  • Panizzon MS, Hauger R, Dale AM, Eaves LJ, Eyler LT, Fischl B, Fennema-Notestine C, Franz CE, Grant MD, Jak AJ, Jacobson KC, Lyons MJ, Mendoza SP, Neale MC, Prom-Wormley EC, Seidman LJ, Tsuang MT, Xian H, Kremen WS. Testosterone modifies the effect of APOE genotype on hippocampal volume in middle-aged men. Neurology. 2010;75:874-880.
  • Chen CH, Panizzon MS, Eyler LT, Jernigan TL, Thompson W, Fennema-Notestine C, Jak AJ, Neale MC, Franz CE, Hamza S, Lyons MJ, Grant MD, Fischl B, Seidman LJ, Tsuang MT, Kremen WS, Dale AM. Genetic influences on cortical regionalization in the human brain. Neuron. 2011;72:537-544.
  • Franz CE, Lyons MJ, O'Brien R, Panizzon MS, Kim K, Bhat R, Grant MD, Toomey R, Eisen S, Xian H, Kremen WS. A 35-year longitudinal assessment of cognition and midlife depression symptoms: The Vietnam Era Twin Study of Aging. Am. J. Geriatr. Psychiatry. 2011;19:559-570.
  • Chen CH, Gutierrez ED, Thompson W, Panizzon MS, Jernigan TL, Eyler LT, Fennema-Notestine C, Jak AJ, Neale MC, Franz CE, Lyons MJ, Grant MD, Fischl B, Seidman LJ, Tsuang MT, Kremen WS, Dale AM. Hierarchical genetic organization of human cortical surface area. Science. 2012;335:1634-1636.
  • Vuoksimaa E, Panizzon MS, Chen C-H, Eyler LT, Fennema-Notestine C, Fiecas MJ, Fischl B, Franz CE, Grant MD, Jak AJ, Lyons MJ, Neale MC, Thompson WK, Tsuang MT, Xian H, Dale AM, Kremen WS. Cognitive reserve moderates the association between hippocampal volume and episodic memory in middle age. Neuropsychologia. 2013;51:1124-1131.
  • Chen CH, Fiecas M, Gutierrez ED, Panizzon MS, Eyler LT, Vuoksimaa E, Thompson WK, Fennema-Notestine C, Hagler DJ, Jr., Jernigan TL, Neale MC, Franz CE, Lyons MJ, Fischl B, Tsuang MT, Dale AM, Kremen WS. Genetic topography of brain morphology. Proc Natl Acad Sci U S A. Oct 15 2013;110(42):17089-17094.
  • Lyons MJ, Genderson M, Grant MD, Logue M, Zink T, McKenzie R, Franz CE, Panizzon M, Lohr JB, Jerskey B, Kremen WS. Gene-environment interaction of ApoE genotype and combat exposure on PTSD. American Journal of Medical Genetics B Neuropsychiatric Genetics. 2013;162:762-769.
  • Moore CS, Grant MD, Zink TA, Panizzon MS, Franz CE, Logue MW, Hauger RL, Kremen WS, Lyons MJ. Erectile dysfunction, vascular risk, and cognitive performance in late middle age. Psychol. Aging. Mar 2014;29(1):163-172.
  • Kremen WS, Panizzon MS, Franz CE, Spoon KM, Vuoksimaa E, Jacobson KC, Vasilopoulos T, Xian H, McCaffery JM, Rana BK, Toomey R, McKenzie R, Lyons MJ. Genetic complexity of episodic memory: A twin approach to studies of aging. Psychol. Aging. Jun 2014;29(2):404-417.
  • Kremen WS, Jak AJ, Panizzon MS, Spoon KM, Franz CE, Thompson WK, Jacobson KC, Vasilopoulos T, Vuoksimaa E, Xian H, Toomey R, Lyons MJ. Early identification and heritability of mild cognitive impairment. Int. J. Epidemiol. Apr 2014;43(2):600-610.
  • Vuoksimaa E, Panizzon MS, Chen C-H, Fiecas M, Eyler LT, Fennema-Notestine C, Hagler DJ, Jr., Fischl B, Franz CE, Jak AJ, Lyons MJ, Neale MC, Rinker DA, Thompson WK, Tsuang MT, Dale AM, Kremen WS. The genetic association between neocortical volume and general cognitive ability is driven by surface area rather than thickness. Cereb. Cortex. 2014:Epub ahead of print.
  • Jak AJ, Panizzon MS, Spoon KM, Fennema-Notestine C, Xian H, Eyler LT, Vuoksimaa E, Toomey R, Lyons MJ, Neale MC, Tsuang MT, Dale AM, Kremen WS. Hippocampal atrophy varies by neuropsychologically-defined MCI among men in their 50s. Am. J. Geriatr. Psychiatry. 2014:in press.