which is taken up by trying to fulfill the immediate physical needs . There is a normal and immediate stress response that comes with an event that causes damage to homes and infrastructure and loss of family members , David said . Haiti has the potential for higher rates of mental illness and a slower recovery after this episode because the population is already strained from weak social and economic supports , Galea said . In those conditions , they may already be predisposed to developing mental illness irrespective of the earthquake itself , he said . View or add to CNN 's database of missing persons in Haiti The stress of the disaster situation , combined with the potential predisposition toward stress disorders , could lead to an extreme emotional reaction , but that does not mean these factors predict any kind of violent or other extreme behavior , said Joan Cook , assistant professor of psychiatry at Yale University , in an e-mail . `` I 'd say that if the rate of psychological problems turns out similar to previous severe natural disasters in other economically disadvantaged countries , as many as 50 percent or more could suffer
-LRB- CNN -RRB- -- As Haitians struggle to recover from the devastation of Tuesday 's 7.0-magnitude earthquake , mental health experts caution that the most severe psychological effects wo n't take form until individuals ' situations stabilize . Feelings of confusion , fear , agitation , grief and anger that surround a large-scale traumatic event such as the Haiti earthquake give way to more pronounced psychological disorders once people 's basic human needs are taken care of , experts say . `` Once the initial resources are in , when actually most people are going to start feel out of danger , is when the psychological aftereffects are going to hit people , '' said Dr. Daniella David , professor of clinical psychiatry at the University of Miami 's Miller School of Medicine . `` People need to ask for help when that happens . '' In the immediate short-term period after a large-scale traumatic event , people are concerned primarily with self-preservation and taking care of family and friends , said Dr. Sandro Galea , chair of the Department of Epidemiology at Columbia University 's Mailman School of Public Health . These people experience acute stress and anxiety ,