Exhibit A

Exhibit 99.A

Exhibit A

Agreement of Reporting Persons

Each of the undersigned hereby agrees that the Amendment No. 6 to Schedule 13D filed on the date hereof with respect to the shares of Common Stock of Psychiatric Solutions, Inc. has been filed on behalf of the undersigned.

Signature

Dated: May 10, 2004

Entities:

Oak Investment Partners VI, Limited Partnership

Oak Associates VI, LLC

Oak Investment Partners X, Limited Partnership

Oak Associates X, LLC

Oak X Affiliates Fund, Limited Partnership

Oak X Affiliates, LLC

Oak Management Corporation

	By:	/s/ Xxxxxx X. Xxxxxxxxxx
		Xxxxxx X. Xxxxxxxxxx, as
		General Partner or
		Managing Member or as
		Attorney-in-fact for the
		above-listed entities

Individuals:

Bandel X. Xxxxxx

Xxxxxx X. Xxxxxxxxx

Xxxxxx X. Xxxxxxxxxx

Xxxxxxx X. Xxxxxx

Xxx X. Xxxxxx

Xxxxx X. Xxxxxx

	By:	/s/ Xxxxxx X. Xxxxxxxxxx
		Xxxxxx X. Xxxxxxxxxx,
		Individually and as
		Attorney-in-fact for the
		above-listed individuals