Schizophrenia genes increase chance of IQ loss

February 21, 2013, University of Edinburgh

People who are at greater genetic risk of schizophrenia are more likely to see a fall in IQ as they age, even if they do not develop the condition.

Scientists at the University of Edinburgh say the findings could lead to new research into how different genes for schizophrenia affect over time. They also show that genes associated with schizophrenia influence people in other important ways besides causing the illness itself.

The researchers used the latest techniques to reach their conclusion on how thinking skills change with age.

They compared the IQ scores of more than 1,000 people from Edinburgh who were tested for general cognitive functions in 1947, when the subjects were aged 11, and again when they were around 70 years old.

The researchers were able to examine people's genes and calculate each subject's genetic likelihood of developing schizophrenia, even though none of the group had ever developed the illness.

They then compared the of people with a high and low risk of developing schizophrenia. They found that there was no difference at age 11, but people with a greater of schizophrenia had slightly lower IQs at age 70.

Those people who had more genes linked to schizophrenia also had a greater estimated fall in IQ over their lifetime than those at lower risk.

Ian Deary, Director of the University of Edinburgh's Centre for Cognitive Ageing and Cognitive Epidemiology, who led the research team, said: "Retaining our thinking skills as we grow older is important for living well and independently. If nature has loaded a person's genes towards schizophrenia, then there is a slight but detectable worsening in cognitive functions between childhood and old age."

Andrew McIntosh, of the University of Edinburgh's Centre for Clinical , said: "With further research into how these genes affect the brain, it could become possible to understand how genes linked to schizophrenia affect people's cognitive functions as they age."

Explore further: Study finds bidirectional relationship between schizophrenia and epilepsy

More information: The study is published in the journal Biological Psychiatry.

Related Stories

Study finds bidirectional relationship between schizophrenia and epilepsy

September 19, 2011
Researchers from Taiwan have confirmed a bidirectional relation between schizophrenia and epilepsy. The study published today in Epilepsia, a journal of the International League Against Epilepsy (ILAE), reports that patients ...

Immune dysfunction possibly linked to schizophrenia

October 19, 2012
Schizophrenia is a complex illness; among other characteristics, sufferers often find it difficult to tell the difference between what is real and not real and have trouble thinking clearly. Its symptoms could develop over ...

Recommended for you

Early life trauma in men associated with reduced levels of sperm microRNAs

May 22, 2018
Exposure to early life trauma can lead to poor physical and mental health in some individuals, which can be passed on to their children. Studies in mice show that at least some of the effects of stress can be transmitted ...

Training compassion 'muscle' may boost brain's resilience to others' suffering

May 22, 2018
It can be distressing to witness the pain of family, friends or even strangers going through a hard time. But what if, just like strengthening a muscle or learning a new hobby, we could train ourselves to be more compassionate ...

Study finds popular 'growth mindset' educational interventions aren't very effective

May 22, 2018
A new study co-authored by researchers at Michigan State University and Case Western Reserve University found that "growth mindset interventions," or programs that teach students they can improve their intelligence with effort—and ...

Schizophrenics' blood has more genetic material from microbes

May 22, 2018
The blood of schizophrenia patients features genetic material from more types of microorganisms than that of people without the debilitating mental illness, research at Oregon State University has found.

Kids show adult-like intuition about ownership

May 22, 2018
Children as young as age three are able to make judgements about who owns an object based on its location, according to a study from the University of Waterloo.

Age-related racial disparity in suicide rates among US youth

May 21, 2018
New research suggests the suicide rate is roughly two times higher for black children ages 5-12 compared with white children of the same age group. The study, funded by the National Institute of Mental Health (NIMH), appears ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.