Superior Court Judge Larry Paul Fidler made the statements after intense arguments in which defense attorney Christopher Plourd said the writings found on her computer hard drive also include discussions of her fascination with guns, depression over her failing acting career, and struggles with alcohol and drugs.
Prosecutors acknowledged they knew about the material but considered it untrustworthy and did not alert the coroner who concluded that Clarkson was a homicide victim.
Clarkson died of a shot fired inside her mouth in the foyer of Spector's mansion more than four years ago after going home with him from her job as a nightclub hostess. Spector's defense contends Clarkson killed herself.
The issue emerged as Deputy Medical Examiner Louis Pena testified he did not consider doing a "psychological autopsy" on Clarkson. He said information he obtained about Clarkson convinced him she was a hopeful person with no tendency toward suicide. A psychological autopsy is done only at the family's request if a death is a suicide, he said.
Photos: The Phil Spector Trial
Asked whether he considered the writings, Pena said they weren't provided to him. Plourd asked whether his opinion would have changed if they had been, and the judge dismissed jurors so the issue could be discussed outside of their presence.
Once jurors were gone, Plourd disclosed some of the contents of the writings, including a Clarkson composition called "The Story of My Life."
In the document, Plourd said, she discussed having had drug problems in her youth and said she drank 17 shots of tequila on her 17th birthday.
"She has delusions," Plourd said. "She's seeing people who are deceased and talks to them. She talks about seeing a dead actress who comes to her in visions, a struggling actress who didn't make it and killed herself with a gun."
He also cited e-mails Clarkson sent to a friend in which she said she was despairing over money and wanted to get her affairs in order and "chuck it." He argued Pena should be questioned about whether the writings would have influenced his ruling.
"If you consider this information, it weakens and shakes his opinion," Plourd said.
Plourd said that a district attorney's investigator read the diary and concluded it didn't contain anything relevant to the case. Prosecutors gave it to the coroner's office as part of a bundle of information and said they could look at it if they wanted to do a psychological autopsy, he said.
Prosecutor Alan Jackson said the writings were not authenticated, could not be relied upon and were probably done for a writing class Clarkson was taking.
The judge, who at one point referred to the writings as a "memoir," appeared to disagree.
"I think you are arguing way too much," Fidler said to Jackson. "If you have the words of a deceased ... how do you keep that away from the jury and away from an expert who could have considered it?"
The judge said he would read the entire manuscript over the weekend and make a ruling. But before court ended, he said he had read some of it and was inclined to admit it in evidence.
Also Thursday, defense attorney Roger Rosen complained that prosecutors had subpoenaed New York University for forensic expert Henry Lee's undergraduate record.
Last week, the judge ruled that Lee found evidence during a defense survey of the shooting scene and never provided it to the prosecution. The prosecution claims the item was a piece of Clarkson's fingernail.
"This is tantamount to harassment," said Rosen, who suggested it may have been a move to send a message to Lee, one of the defense's most critical witnesses.
Deputy District Attorney Pat Dixon said he believed the subpoena was sent before the hearing involving Lee ended last week. Lee has denied withholding evidence, said he believes he has been slandered and said the motive is to undermine his upcoming testimony.
Clarkson, 40, was best known for her role in Roger Corman's 1985 cult film "Barbarian Queen." She had gone home with Spector from her job as a hostess at the House of Blues nightclub on the Sunset Strip before the shooting Feb. 3, 2003.
Spector, 67, gained fame in the 1960s with a recording technique known as the "Wall of Sound" that produced many hit records.