ANNAPOLIS, FEB. 5 -- The Patuxent Institution's controversial psychiatric counseling programs have no discernible effect on prisoner recidivism, a consultant has concluded.

In a report presented to legislators today, Massachusetts-based Abt Associates said its research shows that former Patuxent inmates are just as likely to be rearrested as are people released from other state prisons included in the study.

The report is another blow to a prison once hailed as a model for its work with murderers, rapists and other violent offenders.

Two years ago, the prison's furlough of Montgomery County triple-murderer Robert Daly Angell triggered a public outcry and focused attention on the facility's use of early release as an incentive. Legislators, concerned that psychiatric theory had taken precedence over public safety, ultimately stripped away much of the institution's unique parole-granting authority and restricted its admissions policies.

Those changes effectively ended Patuxent as it was conceived in the early 1970s, a place setting its own rules, where psychiatric experts would try to rehabilitate society's most incorrigible criminals.

The consultant's study was commissioned to see if the prison's program, a blend of individual psychotherapy and group counseling coupled with the promise of an early out, was doing any good.

With the results of that study now in hand, legislators say they may move to merge Patuxent completely with the state prison system. If it maintains any distinct identity, they said, it would likely be as a facility that focuses on young offenders, drug addicts or others for whom treatment is considered most likely to succeed.

"The bottom line is that there are no demonstrable or measurable effects," said Del. Timothy F. Maloney (D-Prince George's), chairman of a corrections subcommittee. "From an administrative and budgetary standpoint, Patuxent is sort of fading out of existence . . . . The only issue now is what the new mission will be."

Patuxent Director Joseph Henneberry, who has been steering Patuxent toward younger inmates with shorter sentences, cautioned that the study was not exhaustive. Maintaining recidivism rates equal to those of other prisons might even be viewed as a success, Henneberry suggested, because Patuxent accepted some of the state's worst offenders. In addition, he said, the research did not account for subtleties such as a murderer's being rearrested on a lesser charge.

The study estimated that 45 percent of Patuxent inmates were rearrested within three years of release from the institution, a rate the consultants said was statistically indistinguishable from that of groups culled from other state prisons.

Lawmakers focused on the $3,000 extra per inmate that the state spends on Patuxent's approximately 550 prisoners and suggested that might be a ready source of cash in tight budget times.

"What is . . . disappointing is that there is no clear evidence that the institution's treatment program wrought positive effects on prisoners," the study concluded.

"We have continued the fiction of Patuxent but not much of the reality," said Maloney, who predicted that Patuxent would be turned into a "plain vanilla-type institution" within the next year.