New study suggests hallucinations, alone, do not predict onset of schizophrenia

October 8, 2015
Functional magnetic resonance imaging (fMRI) and other brain imaging technologies allow for the study of differences in brain activity in people diagnosed with schizophrenia. The image shows two levels of the brain, with areas that were more active in healthy controls than in schizophrenia patients shown in orange, during an fMRI study of working memory. Credit: Kim J, Matthews NL, Park S./PLoS One.

Despite decades of study, schizophrenia has remained stubbornly difficult to diagnose in its earliest stage - between the appearance of symptoms and the development of the disorder. Now, a new analysis led by researchers at the UNC School of Medicine and the Renaissance Computing Institute (RENCI) identified illogical thoughts as most predictive of schizophrenia risk. Surprisingly, perceptual disturbances - the forerunners of hallucinations - are not predictive, even though full-blown hallucinations are common features of schizophrenia. The results were published online today in the journal Schizophrenia Research.

"The earlier people are identified and receive treatment when they develop schizophrenia, the better their prognosis," said Diana Perkins, MD, a clinician and professor of psychiatry at the UNC School of Medicine and one of the study's first authors. "If we can identify people at for psychosis we can then develop interventions to prevent the development of schizophrenia and the functional declines associated with it."

Schizophrenia is a chronic mental illness that affects more than 3 million people in the United States. It typically emerges during late adolescence and early adulthood, and remains a chronic and disabling disorder for most patients. Psychosis, which more than 6 million Americans experience, refers to a group of symptoms, including paranoia, delusions (false beliefs), hallucinations, and disorganization of thought and behavior. Psychosis always occurs in schizophrenia, but can also occur in people with bipolar disorder or other medical conditions.

Early warning signs of schizophrenia include mild psychosis-like symptoms. However, only about 15-20 percent of people who have these mild psychosis-like symptoms actually develop or other disorders with full-blown psychosis. Current diagnostic criteria for attenuated psychosis include having at least one of the following: illogical thoughts, disorganized thoughts, or perceptual disturbances of sufficient frequency and severity to impact function.

To help clinicians know where to draw the line, Perkins and Jeffries examined what symptoms were most predictive of psychosis over a two-year follow-up period in a cohort of 296 individuals at high-risk for psychosis because of experiencing attenuated psychosis symptoms. The analysis revealed that suspiciousness and unusual thought content were the most predictive, and that difficulty with focus or concentration and reduced ideational richness further enhanced psychosis risk prediction.

Identification of the most informative symptoms was performed with "stringent randomization tests," according to the other first author, Clark D. Jeffries, PhD, a scientist at RENCI. That means the same classifier algorithm was applied to the true data as well as 1000 random permutations of the data that mixed patients who did and did not progress to frank psychosis.

Importantly, the investigators validated these findings in a new cohort of 592 people with attenuated psychosis symptoms, confirming the findings. Suspiciousness and unusual thought content include a "feeling of being watched," or "it seeming like others are talking about" the person but knowing that this "can't really be true," or fixating on coincidences that aren't actually connected, or finding "signs" in certain experiences or having a distorted sense of time.

Difficulty with focus and concentration refers to problems with distractibility and short-term memory. Reduced ideational richness typically refers to difficulty following conversations or engaging in abstract thinking.

Somewhat surprisingly, perceptual disturbances - seeing shadows or hearing knocking noises with a sense that these experiences are "not real," - while superficially similar to hallucinations were not predictive of psychosis. Although such were common in those who developed psychosis, they were equally common in those who did not develop psychosis.

"In terms of assessing psychosis risk, I think this study shows we need to be emphasizing the person's thought process, and appreciate that perceptual disturbances may not be a specific early warning sign," Perkins said. "I think that will affect how we develop our diagnostic system in the future for people who are at high risk for ."

Explore further: Adolescents exhibiting symptoms of mental disorders should be asked about hallucinations

Related Stories

Adolescents exhibiting symptoms of mental disorders should be asked about hallucinations

January 22, 2015
Visual distortions and hallucinations related to an elevated risk of psychosis are linked to self-destructive thought processes among adolescents with psychological symptoms, according to a recent Finnish study. Early indications ...

Identifying youth as 'at risk' for mental problems may be less a stigma than the symptoms

September 29, 2015
There is an emergent and promising field of research on schizophrenia prevention, yet little is known about the potential harm and risks inherent in identifying and labeling young people at risk. A study led by researchers ...

Blood test may help determine who is at risk for psychosis

September 22, 2014
A study led by University of North Carolina at Chapel Hill researchers represents an important step forward in the accurate diagnosis of people who are experiencing the earliest stages of psychosis.

Who will develop psychosis? Automated speech analysis may have the answer

August 26, 2015
An automated speech analysis program correctly differentiated between at-risk young people who developed psychosis over a two-and-a-half year period and those who did not. In a proof-of-principle study, researchers at Columbia ...

Aristada approved for schizophrenia

October 6, 2015
(HealthDay)—Aristada (aripiprazole lauroxil) extended release injection has been approved by the U.S. Food and Drug Administration to treat the disabling brain disorder schizophrenia, the agency said Tuesday in a news release.

Antipsychotics increase risk of death in people with Parkinson's disease psychosis

September 30, 2015
Antipsychotic drugs may increase the risk of death in people with Parkinson's disease psychosis (PDP), according to a new study led by researchers from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King's ...

Recommended for you

Schizophrenia drug development may be 'de-risked' with new research tool

November 22, 2017
Researchers at Columbia University Medical Center (CUMC) and the New York State Psychiatric Institute (NYSPI) have identified biomarkers that can aid in the development of better treatments for schizophrenia.

Study finds infection and schizophrenia symptom link

November 22, 2017
If a mother's immune system is activated by infection during pregnancy, it could result in critical cognitive deficits linked to schizophrenia in her offspring, a University of Otago study has revealed.

Self-harm, suicide attempts climb among US girls, study says

November 21, 2017
Attempted suicides, drug overdoses, cutting and other types of self-injury have increased substantially in U.S. girls, a 15-year study of emergency room visits found.

Car, stroller, juice: Babies understand when words are related

November 20, 2017
The meaning behind infants' screeches, squeals and wails may frustrate and confound sleep-deprived new parents. But at an age when babies cannot yet speak to us in words, they are already avid students of language.

Simple EKG can determine whether patient has depression or bipolar disorder

November 20, 2017
A groundbreaking Loyola Medicine study suggests that a simple 15-minute electrocardiogram could help a physician determine whether a patient has major depression or bipolar disorder.

Non-fearful social withdrawal linked positively to creativity

November 20, 2017
Everyone needs an occasional break from the social ramble, though spending too much time alone can be unhealthy and there is growing evidence that the psychosocial effects of too much solitude can last a lifetime.

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.