Incidence of psychological trauma and post-traumatic stress disorder have more than doubled in Gaza since Israel's November war in the enclave, the UN agency for Palestinian refugees says.

Since Israel's eight-day bombardment of Gaza, which ended on Nov. 21, 42 percent of patients treated by UNRWA for psychological trauma have been under the age of nine, the agency says. 

"These figures represent a significant rise in mental health problems," said Akihiro Seita, director of UNRWA’s health program. "From my experience, I would say this is evidence of a psychological trauma and PTSD epidemic."

Seita added that the statistics did not include unreported cases of trauma. 

"All the mothers I met in UNRWA's health centers said their children behaved differently during and after the war. Some don't sleep well, some don't eat well, and some don't speak well."

UNICEF conducted a rapid psychosocial assessment of children in Gaza in December and found a 91 percent of increase in sleep disturbances, while 84 per cent of respondents were reported as looking "stunned or dazed." 

"UNRWA is stepping up its psychosocial counseling at schools and through home visits in response to this sharp rise in PTSD cases." said UNRWA spokesman Chris Gunness.

Gunness said UNRWA's community mental health program in Gaza cost $3 million annually and that the agency was in need of more funding to meet growing demand.