According to a McClatchy-Tribune report in the Baltimore Sun (part of the Tribune Company) "Mental hospital official held in blasts":
Iraqi authorities announced within hours of the blasts that the perpetrators were teenage girls with Down syndrome who might have been unwilling participants. U.S. authorities now think that version of events was inaccurate.
A senior U.S. official who asked not to be named because he wasn't authorized to discuss the case publicly said U.S. investigators now thought that the bombers were adults - one in her 20s, the other in her 30s - with long histories of psychiatric conditions, including depression and schizophrenia.
Investigators think that early Iraqi accounts that the bombers escaped security efforts because they were well-known in the two markets where the bombings occurred also were incorrect. While one of the women was from Baghdad, the other was from outside the city, the senior U.S. official said.
Also a recent AP report about Iraq rounding up beggars and the mentally ill notes that:
The decision, which elicited concern from advocates for the mentally disabled, came nearly three weeks after twin suicide bombings against pet markets. Officials said those blasts were carried out by mentally disabled women who may have been unwitting attackers.
The U.S. military and the Iraqi government have claimed that Sunni insurgents led by al-Qaida in Iraq are increasingly trying to use Iraq's most vulnerable populations as suicide bombers to avoid raising suspicions or being searched at checkpoints that guard access to many markets, neighborhoods and bridges in the capital.
The AP report continued:
However, it is not clear that such people would be safe in psychiatric hospitals. American and Iraqi troops recently detained the acting director of the al-Rashad psychiatric hospital in eastern Baghdad on suspicion of helping supply patient information to al-Qaida in Iraq.
As the McClatchy-Tribune report linked above also informed us.
The AP offers more details and confirmation that at least one of the bombers was not a down syndrome teen.
The Iraqi claim that mentally disabled women were used in the Feb. 1 pet market bombings was met initially with skepticism. Iraqi authorities said they based the assertion on photos of the bombers' heads that purportedly showed the women had Down syndrome, and did not offer any other proof.
However, the director of the Ibn-Rushd psychiatric teaching hospital in central Baghdad, Dr. Shalan al-Abboudi, said that one of the pet market bombers, a 36-year-old married woman, had been treated there for schizophrenia and depression, according to her file. Refusing to identify her, he said she received electric shock therapy and was released into the custody of an aunt.
The AP wonders how authorities plan to round up homeless and beggars who are even better than the general public at hiding their identities.
Much more interesting info is in the two reports linked above, including outrage from a rights activist for the mentally 'disabled' from the AP. The activist questions whether the shocks of our invasion and poorly done occupation may have caused mental vulnerabilities for many, which is what I was thinking.