Hallucinations, delusions linked to poorer outcomes in general population

Sep 12 2012

By Mark Cowen, Senior medwireNews Reporter

The occurrence of hallucinations and delusions is associated with poorer mental health outcomes in the nonclinical general population, researchers report.

The team also found that people who experience both hallucinations and delusions have poorer mental health outcomes than those who experience either of these symptoms in isolation.

"The findings are congruent with the hypothesis that co-occurrence of hallucinations and delusions in the non-clinical population, compared with the occurrence of either in isolation, may represent an important early indicator of clinical relevance," say José Ayuso-Mateos (Universidad Autónoma de Madrid, Spain) and team.

The researchers examined data on 225,842 individuals (55.6% women), aged 18-65 years (mean age 37.3 years) from 52 countries, who answered questions about psychotic symptoms as part of the World Health Organization's World Health Survey.

Overall, 87.3% of individuals did not report any psychotic symptoms in the previous 12 months, 1.8% reported isolated hallucinations, 7.2% reported isolated delusions, and 3.6% reported experiencing both hallucinations and delusions.

After accounting for age, gender, World Bank category, and country, the researchers found that people with isolated hallucinations or delusions had an increased risk for being diagnosed with a psychotic disorder (odds ratios [ORs]=7.49 and 6.07, respectively), receiving treatment for psychotic symptoms (ORs=7.24 and 7.58, respectively), and being depressed in the previous 12 months (ORs=3.32 and 5.74, respectively) than those without such symptoms.

However, the risk for these poorer outcomes was much greater in those with both hallucinations and delusions.

Indeed, compared with individuals without such symptoms, those with both hallucinations and delusions were 12.9 times more likely to have been diagnosed with a psychotic disorder, 19.7 times more likely to have received treatment for psychotic symptoms, and 11.6 times more likely to have been depressed in the previous 12 months.

Individuals with co-occurring hallucinations and delusions also had reduced general health and functioning, and were more likely to have hearing problems (OR=2.01) and vision problems (OR=1.54) compared with those without such symptoms.

The researchers also note that individuals with co-occurring hallucinations and delusions had a greater severity of such symptoms than those with isolated symptoms.

Ayuso-Mateos et al conclude in Acta Scandinavica Psychiatrica: "The results suggest that the co-occurrence of hallucinations and delusions in populations is not random but instead can be seen, compared with either phenomenon in isolation, as the result of more etiologic loading leading to a more severe clinical state."

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