MIXED LATERAL PREFERENCE AND PARENTAL LEFT-HANDEDNESS: POSSIBLE MARKERS OF RISK FOR PTSD.

Degree of lateral preference (mixed versus consistent), family history of parental left-handedness, and presence of posttraumatic stress disorder (PTSD) were measured in 118 right-handed male U.S. combat veterans. Right-handed participants with mixed lateral preference were more likely to have PTSD than were right-handers with consistent lateral preference. Respondents reporting a left-handed parent were also more likely to have PTSD. Finally, there was a significant difference in the proportion of participants with PTSD for three groups: participants with parental left-handedness and mixed lateral preference (100% PTSD), participants with parental left-handedness or mixed lateral preference (70% PTSD), and participants with neither parental lefthandedness nor mixed lateral preference (44% PTSD). These findings suggest the possible usefulness of further examining the relationship between mixed lateral preference, parental left-handedness, and other possible indicators of risk for PTSD.