Fol­lowing last month’s severe earth­quake, Japan has endured two strong after­shocks in less than a week, knocking out power in some areas and undoubt­edly inten­si­fying the anx­i­eties of res­i­dents. Here, Hort­ensia Amaro, Dis­tin­guished Pro­fessor and asso­ciate dean in Bouvé Col­lege of Health Sci­ences, dis­cusses the role post-​​traumatic stress dis­order (PTSD) may be playing in the lives of the Japanese people today.

What are the cri­teria for a diag­nosis of PTSD?

There are six cri­teria spec­i­fied in the Diag­nostic and Sta­tis­tical Manual of Mental Dis­or­ders. First, you have to be exposed to a trau­matic event that involves the threat of death or serious injury, or a threat to the phys­ical well-​​being of others. Second, you re-​​experience the trau­matic event through recur­rent and dis­tressing rec­ol­lec­tions, fright­ening dreams or intense dis­tress in response to cues that remind you of the event. Third, you avoid thoughts, places and people asso­ci­ated with the event, and your gen­eral respon­sive­ness seems numbed. Fourth, you exhibit symp­toms of increased arousal, such as sleep dif­fi­cul­ties, irri­tability, prob­lems with con­cen­trating, hyper­vig­i­lance or an exag­ger­ated startle response. Fifth, the symp­toms last for more than a month. And sixth, the symp­toms cause you clin­i­cally sig­nif­i­cant dis­tress or impair­ment in your daily life.

Given the recent cat­a­stro­phes in Japan, are its inhab­i­tants likely to expe­ri­ence PTSD? Could these tragedies cause PTSD in people in other parts of the world, too?

People who lived through the earth­quake in Japan could cer­tainly expe­ri­ence PTSD, although not all indi­vid­uals in Japan will meet the cri­teria. From pre­vious research, we know that dis­aster sur­vivors are quite likely to expe­ri­ence psy­cho­log­ical prob­lems as well as declines in their phys­ical health, including a greater vul­ner­a­bility to car­dio­vas­cular disease.

The extent to which the people of Japan will expe­ri­ence PTSD depends on many fac­tors: the direct­ness of their expo­sure to the event, their degree of loss, their pre­vious per­son­ality and psy­chi­atric pro­file, and the capacity of the gov­ern­ment and other enti­ties to sta­bi­lize daily-​​life activ­i­ties and ensure a sense of safety.

Studies have shown that women, chil­dren, the elderly, the poor and those with pre­vious mental-​​health prob­lems are at a higher risk of expe­ri­encing more-​​serious symp­toms and per­haps longer-​​term effects.

The world­wide impact is dif­fi­cult to pre­dict and assess. People who have had sim­ilar dis­aster expe­ri­ences might be most vul­ner­able, espe­cially those who con­tinue to expe­ri­ence PTSD. Those who live close to the event or in set­tings at high risk for sim­ilar events might be vul­ner­able, too.

How might PTSD caused by the tragedies in Japan be treated?

There is no evidence-​​based con­sensus on the effec­tive­ness of inter­ven­tions in the imme­diate and midterm post-​​trauma phases of a mas­sive dis­aster like this.

How­ever, there are some agreed-​​upon prin­ci­ples that health author­i­ties follow: Pro­mote a sense of safety. Pro­mote calming. Pro­mote self-​​efficacy and col­lec­tive effi­cacy. Pro­mote a sense of con­nect­ed­ness. And instill hope.

These prin­ci­ples sug­gest what the Japanese gov­ern­ment needs to do, both in its mes­sages and in the ser­vices it pro­vides: Ease stress. Build con­nect­ed­ness and hope. And refocus people’s atten­tion on nor­malcy rather than on the tragedy.