A 17-year-old Gaithersburg youth admitted yesterday that he was involved in a masked attack in which a Germantown man survived being hacked several times with a hatchet.

The Watkins Mill High School student said little as he entered his plea in Montgomery County juvenile court of being involved--the juvenile court term for guilty--in the Aug. 10 attack that left the man with chop marks on his head and back.

Assistant Montgomery State's Attorney Paul Zmuda told District Court Judge Dennis McHugh that the teenager and 18-year-old John Overholser dressed in black and wore masks with plastic goggles usually worn in paint-ball competitions. After David Dorland answered their knock at the front door of his home in the 12600 block of Grey Eagle Court, Zmuda said, the pair barged in with Overholser wielding a hatchet.

The Post does not generally publish the names of youths tried in juvenile court. Overholser, who is being tried as an adult, has pleaded not guilty to six charges, including attempted first-degree murder, and is awaiting trial.

After Overholser entered the apartment swinging the hatchet and chopping Dorland behind his left ear, Zmuda said, the two struggled over the hatchet while the youth ran toward Dorland's girlfriend. The girlfriend locked herself in the bedroom and called police as Dorland was struck several more times with the hatchet.

While there is "some confusion" over whether the youth also had a weapon, Zmuda told the judge, "there is no confusion" that the teenager punched Dorland several times.

Zmuda said the attack was prompted by Overholser's belief that the victim had sexually harassed his girlfriend at work.

The youth initially was indicted as an adult on four charges, including attempted murder, but prosecutors charged him only with first-degree assault after the case was transferred to juvenile court. The youth pleaded guilty yesterday to that charge.

McHugh ordered that he continue to be held at the Alfred D. Noyes juvenile detention facility before his disposition hearing, or sentencing, Jan. 18.

Although first-degree assault carries a maximum 25-year penalty in adult court, defendants whose cases are adjudicated in juvenile court can be detained only until they are 21.

Defense attorney David Felsen said his client has been diagnosed with hyperactivity, attention deficit disorder and bipolar disorder. Four days before the attack, Felsen said, doctors increased the youth's psychiatric medication dosage ten-fold, and he was drinking alcohol that night.

"That doesn't make for the most rational of decisions," Felsen said.

Felsen said that Watkins Mill officials do not want the teenager to return to campus but that no decision had been made on his schooling.

McHugh said he was angry upon hearing from the youth's parents that he had not gotten his mood-stabilizing medication at least seven times during his incarceration at Noyes.

"This is another failure on the part of the Department of Juvenile Justice to do what they should," McHugh said.

Noyes Superintendent Clara Miley, who did not attend the hearing, said medical records show that the youth received his medication daily, except for one time when he refused to take it.