Schizophrenics more likely to develop dementia

accreditation
iStock

Older adults who have schizophrenia appear to face a higher risk of getting dementia, new research suggests.

"The rates of dementia in those with schizophrenia in the study were twice that of non-schizophrenic patients," said lead researcher Hugh Hendrie, a Regenstrief Institute investigator and a scientist at the Indiana University Centre for Ageing Research.

On the other hand, while those with schizophrenia were also more likely to develop other health problems, they were less likely to get cancer.

Diagnosis and treatment improved

The study is published in the American Journal of Geriatric Psychiatry.

As the diagnosis and treatment of schizophrenia have improved, those with the mental illness are living longer, researchers noted. But there has been little information about how they fare with other conditions, such as heart problems and dementia, as they age.

So Hendrie's team, from the Regenstrief Institute and Indiana University, looked at the medical records of over 31 000 older adults, average age 70, who received care from an urban public health system, including a mental health centre, from 1999 to 2008.

Over the 10-year span, they zeroed in on 757 adults who had a diagnosis of schizophrenia from a mental health centre. (In all, 1 635 had schizophrenia, but some of those diagnoses were not confirmed at a mental health centre).

Read: Avatars help schizophrenics silence voices

Schizophrenia, a mental illness marked by hallucinations and delusions, is typically diagnosed in adolescence or early adulthood. About 1% of the US population is affected, according to the American Psychiatric Association.

Rate of dementia

The researchers evaluated the rates of common conditions, health use costs and death rates.

They found that those with schizophrenia had higher rates of congestive heart failure: 45% versus 38% in others. They also had more serious lung problems and more instances of low thyroid function.

However, they also had lower rates of cancer, with 30% of them diagnosed with a cancer compared to 43% of other patients.

The big surprise, Hendrie noted, was the rate of dementia. Dementia was twice as common in those with schizophrenia, diagnosed in 64% of those with the mental illness compared to 32% of others.

Those with schizophrenia were also more likely to die during the follow-up period.

"The good news is those with schizophrenia are living longer; the bad news is, they are getting more of the serious physical illnesses than other people," Hendrie said.

Misinterpretation of information

Health care use was higher in those with schizophrenia, which wasn't a surprise, the researchers found. But it was surprising that those patients' admissions to hospital were almost always for physical illness, not the mental illness, Hendrie said.

He can't explain the differences. As for the dementia, he asked: "Does this really mean dementia rates are double in those with schizophrenia? Or is it that the doctors are misinterpreting the information?"

Read: Schizophrenics may fare worse after surgery

When an older person goes to a doctor who has trouble understanding what they are saying, he said, the doctor may think the person is demented, when actually the communication issues may be related to the schizophrenia.

Another possibility, Hendrie said, is that there could be a unique form of dementia that develops in a schizophrenic patient.

Hendrie also can't explain the finding of lower cancer rates. Previous studies have found lower rates of gastrointestinal cancers in those with schizophrenia, he said, and researchers have speculated that the antipsychotic medicines they take may somehow help protect against those cancers.

Integration of services

What is needed, Hendrie added, is a health care system that integrates the mental health and physical health services needed by someone with schizophrenia.

The new finding ''highlights the relationship between the brain and the rest of the body," said Dr Jeff Borenstein, president and CEO of the Brain & Behaviour Research Foundation in New York City.

Experts have known that those with schizophrenia die from medical causes at a much earlier age than those who don't, he added, but the large numbers in the study add strength to the findings. That emphasizes the need to be sure that those with schizophrenia "get treatment not only for schizophrenia, but for physical conditions as well," Borenstein said.

But, he said, "if you are not in a place where that model is in place, you can still have the benefit by making sure the physicians [for mental and physical health services] are talking with each other."

Read more:
Schizophrenics have genetic mutations in brain
Alternative to antipsychotics for schizophrenics

Schizophrenia linked to pregnancy complications

We live in a world where facts and fiction get blurred
In times of uncertainty you need journalism you can trust. For 14 free days, you can have access to a world of in-depth analyses, investigative journalism, top opinions and a range of features. Journalism strengthens democracy. Invest in the future today. Thereafter you will be billed R75 per month. You can cancel anytime and if you cancel within 14 days you won't be billed. 
Subscribe to News24
Voting Booth
The ANC's leadership race is heating up. Who do you think will be elected party president at Nasrec in December?
Please select an option Oops! Something went wrong, please try again later.
Results
Nkosazana Dlamini-Zuma has got it in the bag
7% - 811 votes
I foresee a second term for Cyril Ramaphosa
83% - 9279 votes
Don’t discount a Zweli Mkhize win
10% - 1089 votes
Vote
Rand - Dollar
18.01
-1.3%
Rand - Pound
20.11
+0.1%
Rand - Euro
17.64
-0.4%
Rand - Aus dollar
11.55
-0.0%
Rand - Yen
0.12
-1.0%
Gold
1,713.07
-0.2%
Silver
20.66
+0.1%
Palladium
2,253.50
-0.2%
Platinum
925.00
+0.3%
Brent Crude
93.37
+1.7%
Top 40
59,416
+0.4%
All Share
65,833
+0.3%
Resource 10
63,279
-0.6%
Industrial 25
80,027
+1.0%
Financial 15
13,997
+0.3%
All JSE data delayed by at least 15 minutes Iress logo
Editorial feedback and complaints

Contact the public editor with feedback for our journalists, complaints, queries or suggestions about articles on News24.

LEARN MORE