IIRC he and his family never received any therapy.
I believe it was cases like Steven Staynor (his case was included in a study done by the Center for Missing and Exploited Children) that helped to spur a focus on reconciliation efforts when children are returned to normal family situations following stranger or family abductions. At the time of his return the state of the art was pretty much to dump a kid off in the driveway (actually documented as most likely an airport or train or bus station) and leave it to the family to figure out what to do next. The average length of reunification "service" was about 20 minutes, and only occasionally involved a social worker. Most often it was law enforcement officials.