For a study, researchers sought to explore the interaction and organization of positive symptoms, negative symptoms, and functional domains in people with schizophrenia using network analysis and community identification techniques.
As part of the Consortium on the Genetics of Schizophrenia-2, a cross-sectional study was conducted in 5 geographically dispersed research facilities in the US from July 1, 2010, to January 31, 2014. Between November 2021 and June 2022, data were examined. Schizophrenia or schizoaffective disorder outpatients who were clinically stable were included. Any participants who had a neurologic disease or other Axis I mental disorders was disqualified from the study. Stroke, substance misuse, and brain injuries were further exclusion factors. Over 979 of the 1,415 patients that were contacted were included in the analysis. The Role Functioning Scale, the Scale for the Assessment of Positive Symptoms, and other measurements were utilized. Expected influence, which gauges an item’s relative value to the network by associating it with all others, and community detection and stability, which refer to the existence of statistical clusters and their reproducibility, were the main outcomes.
The total number of participants was 979 outpatients (mean [SD] age, 46  years; 663 men [67.7%]; 390 participants [40%] self-identified as African Americans; 30 [3%] as Asians; 7 [0.7%] as Native Americans; 8 [0.8%] as Pacific Islanders; 412 participants [42.1%] as White; 125 participants [12.8%] as more than one race; and 5 participants [0.5%] did not identify). The most thorough network analysis revealed linkages between anhedonia and both negative and positive symptoms as well as functional domains, with anhedonia having the largest anticipated effect. The effect of positive symptoms was the least as anticipated. Avolition, anhedonia, and work functioning were identified as 3 clusters by community detection analyses, along with positive symptoms, negative symptoms, work functioning, independent living, family ties, and social network, and avolition and anhedonia. About 1,000 bootstrapped samples reproduced hallucinations and delusions (100%), whereas 390 (39%) and 570 (57%), respectively, replicated unusual behavior and cognitive disorder. While the remaining functional domains repeated in 940 samples (94%), negative symptoms and work functioning did so in 730 (73%) and 770 (77%) instances, respectively.
Anhedonia may be a therapeutic target for improving overall functioning given its high centrality and linkages to several functional areas. A particular strategy that places a strong emphasis on avolition may be beneficial for interventions for work functioning.