According to a review of 25 years of research reported in the November issue of Psychological Bulletin, published by the American Psychological Association (APA), males experience more traumatic events on average than do females, yet females are more likely to meet diagnostic criteria for Posttraumatic Stress Disorder (PTSD).

The authors reviewed 290 studies conducted between 1980 and 2005 to determine who is more at risk for potentially traumatic events (PTE) and posttraumatic stress disorder (PTSD), males or females? PTSD is defined as an anxiety disorder precipitated by a traumatic event and characterized by symptoms of re-experiencing the trauma, avoidance and numbing and hyper arousal.

The researchers David F. Tolin, PhD of the Institute of Living and Edna B. Foa, PhD, of the University Of Pennsylvania School Of Medicine found the following:

•Males have a higher risk for traumatic events; women suffer from higher PTSD rates.

•Female study participants were more likely than male study participants to have experienced sexual assault and child sexual abuse.

•Female participants were less likely to have experienced accidents, nonsexual assaults, witness death or injury, disaster or fire and combat or war.

•Sexual trauma may cause more emotional suffering and are more likely to contribute to a PTSD diagnosis than other types of trauma.

•Women's higher PTSD rates were not solely attributable to their higher risk for adult sexual assault and child sexual abuse, explained Tolin. PTSD rates were still higher for women even when both sexes were compared on the same type of trauma.

•"PTSD may be diagnosed more in women in part because of the criteria used to define it. Cognitive and emotional responses to traumatic events make a diagnosis of PTSD more likely. So even though men may experience more traumas, they don't seem to have the same emotional responses to traumatic events," said Tolin and Foa.

•Those participants who experienced multiple traumas may be more vulnerable to re-experiencing old PTSD symptoms when confronted with a new trauma.

•"However, the data suggest that the female victims will have brought to the table a much greater risk of abuse and sexual assault prior to the accident; this could place them at higher risk of developing PTSD after the accident even though the current accident may not have caused all the symptoms," said Tolin.

•The male participants examined in this review were less likely to report anxiety or depression, but were more likely to report behavior and drug problems. They were also more likely to become irritable, angry or violent after traumas.

These findings were consistent regardless of the population and age examined and the type of study and assessment tool used.

Tolin said that responses to trauma can vary from person to person but it is difficult to determine if a person has directly faced the trauma or not. Let us take the example of the research on investigating the traumatic effects of 9/11 terrorist attacks. Tolin says that to a certain extent, a few studies showed that participants' distance from ground zero was directly related to the likelihood of experiencing severe PTSD symptoms. But, at the same time people from all over the U.S. could technically have been classified in research as having 'experienced' a terrorist attack just by watching it on TV. This is a major problem for trauma research because it's hard to determine whether someone has really been traumatized or not.