UPDATED 04/01/11 3:12 p.m.

CHICAGO (CBS) — The body of an 80-year-old woman was found decomposed in a squalid West Rogers Park neighborhood apartment Thursday.

Police were called to the home in a two-story, motel-style apartment building the 2000 block of West Morse Avenue, and found the woman unresponsive.

Cecylia Opilka was pronounced dead at the scene.

Neighbors who hadn’t seen the woman in “a while’’ called police, who went to the home to perform a well-being check, according to News Affairs Officer Laura Kubiak.

Neighbors last saw Opilka in December and she likely died of natural causes during that month, a Belmont Area police sergeant said.

The three-story townhome was filled floor to ceiling with debris, and both the victim and her son were “hoarders,’’ the sergeant said.

While at the home, the 43-year-old son, Ronald Opilka, was interviewed. While removing his wallet to produce identification, a bag of marijuana fell out and he was arrested and charged with misdemeanor possession, Kubiak said.

The woman’s body was decomposed, according to the Cook County Medical Examiner’s office. An autopsy Friday determined Opilka died of heart disease and her death was ruled natural.

Police will not seek criminal charges against the son because he may not have the mental capacity to realize he should have called authorities when his mother died, the sergeant said.

Ronald Opilka does not have a criminal history, according to Kubiak.

The case is similar to several others in the past year. Most recently, police in southwest suburban Hometown had to declare a house filled with papers and other trash a “biohazard,” after Wayne Paetzmann, 73, of the 4500 block of West 87th Street, had to be taken to the hospital from his duplex house.

Village officials said Paetzmann was divorced and lived alone. He worked part time as a Hometown police patrol officer in the 1970s.

In May of last year, Jesse Gaston, 75, and his wife Thelma, 79, were found trapped in their own garbage in their home at 1508 E. 69th St. The conditions were so severe that firefighters had to don hazmat suits before they could go inside the home.

Jesse Gaston was a retired zoologist, his wife a former schoolteacher and classically trained musician. Officials said they became trapped in a tangle of debris in their home possibly as long as two weeks before they were found.

Jesse Gaston died six weeks after they were found, and his wife was too frail to attend the funeral, according to published reports. She had to be moved to a nursing home on the city’s North Side.

When crews cleaned out the Gastons’ two-flat, the damage from all the squalor was so severe that there was talk of having the building torn down.

In July of last year, another high-profile case of hoarding made headlines when a woman’s body was found in her home in Skokie. Marie Davis, 79, was found dead in the 5400 block of Foster Street, resting on debris piled so high she was approximately three feet from the ceiling.

Davis died naturally from a heart attack, in spite of the mounds of trash stuffed into the home she occupied for over three decades. Fire crews had to drill a hole in the roof to get into her house.

Dr. Pat McGrath, of Alexian Brothers Behavioral Health Hospital, is an expert in hoarding. He explained to CBS 2 last year that hoarding is a serious disorder.

“What will happen sometimes is that people will have so much stuff in their home that it starts to get unsteady, and if they bump it the wrong way, it collapses on them,” Dr. McGrath said in May of last year. “It has killed people in the past, actually.”

While pictures of homes with garbage and debris stacked floor to ceiling are hard to fathom, to experts like McGrath, it’s not as rare as you’d think.

Dr. McGrath says what we see as debris, hoarders often view very differently.

“We would see it as junk, but they see it as a part of themselves, or an extension of them” said Dr. McGrath. “It might have something that they’ve touched, it might have their saliva on it. We see that as gross. They see it as, then they’d be throwing away a part of them.”

So they hoard. And McGrath says it’s not because they’re lazy.

“They would like to, in some ways, get rid of some of these things,” he said. “They just don’t know where to start or how to go about it.”

And their brain chemistry is altered by the disorder, so that forcibly removing material from a hoarder can be terrifying.

“It’s a very, very scary process for them to even lose a small piece of paper,” said Dr. McGrath.

If you’re worried that you might be becoming a hoarder, there are a few signs. If you have to start moving around things that are stacked in areas where it shouldn’t be, that could be a sign you’re acquiring too many things.

Also, if you are embarrassed to let anyone come over to your house, that often is a sign that you might be hoarding material.

The Sun-Times Media Wire contributed to this report.