From NBC:
BARTLET FINDS LITTLE REST WHILE C.J. HELPS IMPRISONED REPORTER President Bartlet consults a psychiatrist (guest star Adam Arkin, "Chicago Hope") for a troubling sleep disorder -- and gets a sobering personal assessment -- while C.J. lobbies hard to help secure the release of a White House reporter who's been taken hostage on assignment in the Congo. Elsewhere: Toby knows he will be visited by his irate ex-wife (guest star Kathleen York) when he writes an inflammatory speech that condemns Islam for fanaticism; Sam asks Republican lawyer Ainsley Hayes (guest star Emily Procter) to review a proposed act that calls for payment of U.S. back dues to the United Nations in exchange for special requests; Donna is stunned when she is offered a prestigious and well-paid new job outside the White House.

From TVGuide:
It's five days after the Iowa caucuses and the President hasn't slept a wink, so he sees a shrink, the same one who treated Josh Lyman after he was shot. Meanwhile, Toby clashes with his ex-wife, Rep. Andrea Wyatt (Kathleen York), over an upcoming Presidential speech on foreign policy; a former White House reporter is missing in Congo; an office temp (Alanna Ubach) accuses Sam of ³demeaning² Ainsley Haynes (Emily Procter); and a college friend of Donna's (Paul Fitzgerald) offers her a job at his dot-com startup.