It's too soon to know the full implications of Japan's recent earthquake and tsunami, but one thing is for sure: the events have been traumatic, and a lot of people are going to need a long time to recover. All of which has led to a fascinating Q & A on TIME magazine's Healthland blog about the effectiveness of "psychological first aid"—counseling sought out immediately following a natural disaster or other trauma. The especially striking point is that certain kinds of therapy can actually be harmful, and dramatically increase one's likelihood of being diagnosed with post-traumatic stress disorder:

Experience with past disasters suggest that some types of psychological first aid may help those who have lived through them, but others can actually cause harm. Scott Lilienfeld, a professor of psychology at Emory University, has written and spoken about "critical incident stress debriefing," a technique often used by counselors who travel to disaster sites, such as Ground Zero and New Orleans. Research finds that some versions of this technique may double the chances that a trauma victim will suffer post-traumatic stress disorder (PTSD).

I spoke with Lilienfeld, who is an expert on the research evidence on the risks and benefits of the most commonly employed post-disaster counseling techniques.

So, how could the counseling of survivors immediately after the tsunami and earthquake possibly backfire?

No one knows for sure why it's not a good idea, but given what the research shows, [some kinds of debriefing can be harmful]. It usually involves putting people in groups very shortly after the traumatic event and strongly encouraging them to "Get their feelings out" and "Talk about it" and so on. In classic debriefing, they almost prescribe symptoms, saying things like "Don't be surprised if you start feeling X, Y or Z" or "There's a good chance you'll have nightmares or flashbacks." There's some speculation that that [in itself] might bring some of the symptoms on, so I'm not sure that's a great idea.

Read the full story at TIME Healthland.