Disorganization should be distinguished from reality distortion in schizophrenia
MedWire News: Disorganization may represent a separate set of positive symptoms from reality distortion that is independently linked to neurocognition in schizophrenia patients, scientists suggest.
They found that neurocognition has a stronger relationship with disorganization than with reality distortion and that disorganization is related to many domains of cognitive function, whereas reality distortion is not.
"Our findings support theory and results from several studies in schizophrenia suggesting that positive symptom factors should be considered separately," say Joseph Ventura (University of California, Los Angeles, USA) and colleagues.
The researchers conducted a meta-analysis of 104 studies involving a total of 8015 patients with schizophrenia to determine the magnitude of the relationship between neurocognition and disorganization (eg, conceptual disorganization and bizarre behavior) as compared with reality distortion (delusions and hallucinations).
The relationship between reality distortion and neurocognition was weak, whereas there was a moderate and significant association between disorganization and neurocognition.
When they looked at 40 studies involving 4654 patients that assessed the relationship between neurocognition and reality distortion and disorganization combined, the association was weak but still statistically significant.
Ventura and team also found that disorganization was associated with more domains of neurocognition compared with reality distortion, including attention/vigilance, reasoning and problem solving, and speed of processing. However, attentional deficits were more closely associated with reality distortion than with disorganization.
They note that the notion that disorganization should be considered a separate positive symptom factor is supported by previous studies examining the relationship between positive symptoms and community-based functioning.
"While symptoms such as hallucinations and delusions might not consistently interfere with a person's ability to socialize or to perform at work, the data suggest that disorganization symptoms might be more closely linked to impairments in day-to-day functioning," Ventura and co-workers report in the journal Schizophrenia Research.
They believe that validation of the relationship between neurocognition and disorganization as causal by longitudinal research "would have implications for intervention in schizophrenia."
The team concludes: "If neurocognition is related to disorganization then perhaps improvement in community functioning could be mediated by improvements in disorganization."
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By Lucy Piper