We assessed the psychiatric co-morbidity associated with chronic posttraumatic stress disorder (PTSD) (1-2 years) secondary to personal injury motor vehicle accidents (MVAs) in two studies. In Study 1, we compared the results of SCID assessments for 75 treatment-seeking MVA survivors (51 with PTSD and 24 with symptoms but no PTSD). In Study 2, we compared similar results among 132 MVA survivors who had been followed prospectively for 12+ months after their accidents (19 with PTSD, 32 who had PTSD but who had remitted, and 81 who never met criteria for PTSD). We found comparable levels of current co-morbid major depression (53%), any mood disorder (62-68%), generalized anxiety disorder (26%) and any anxiety disorder (42%) for both groups of participants with chronic PTSD. These rates of co-morbidity were higher than those found in non-PTSD comparison groups with similar MVA histories.