'Broad assessment' of symptoms important for determining psychotic disorder functioning

Rapid screening tools for psychotic disorders available in the DSM-5 had potential clinical utility, according to study results published in Journal of Clinical Psychiatry.

“Empirical work shows that much of psychopathology is captured by [three] higher-order domains situated within a broader hierarchical taxonomy: internalizing (eg, anxiety and depression), externalizing (eg, substance use and antagonism) and psychosis (eg, positive symptoms, but referred to as thought disorder in some models),” Julia M. Longenecker, PhD, of the Campbell Family Mental Health Research Institute in Canada, and colleagues wrote. “These [three] domains emerge consistently across diagnosis, culture, gender and age. Limited research has connected psychosis or the trifactor model to functional outcome measures.

“Given the strong evidence that symptoms outside the psychosis domain are prominent and contribute to functional impairment in psychosis, it is important to simultaneously incorporate all [three] domains in models,” the researchers added.

In the current study, Longenecker and colleagues aimed to assess the roles of psychotic and nonpsychotic symptom domains in predicting functioning across psychotic disorders among 128 outpatients with psychotic spectrum diagnoses. In 2011, participants took part in the DSM-5 Field Trails at the Centre for Addiction and Mental Health in Toronto, in which they provided data via repeated administration of “cross-cutting” brief screening measures that evaluated internalizing symptoms such as anxiety and depression, substance use symptoms such as alcohol and psychoactive drug use, and psychotic symptoms. Self-report and clinician-rated WHO Disability Assessment Schedule 2.0 (WHO-DAS-II) served as assessments of functioning level. Further, the researchers used hierarchical regression to assess the association between symptom domains and disability concurrently and prospectively.

Findings demonstrated a strong association between psychosis and self-reported disability when evaluated in isolation (beta = 0.22; P < .001). Internalizing symptoms most strongly concurrently (beta = 0.31; P < .001) and prospectively (beta = 0.29; P <.001) predicted disability when the researchers included all three symptom domains in analyses. They observed an interaction between internalizing and substance use in the concurrent model, which showed high internalizing symptoms were especially detrimental among individuals with high levels of substance use (beta = 0.08; P < .05). Clinician-rated WHO-DAS-II showed similar results.

“To our knowledge, this is the first study to investigate how individual differences in internalizing, substance use (ie, externalizing) and psychosis symptoms prospectively predict functional disability in persons with severe mental illness,” Longenecker and colleagues wrote. “The findings emphasize the importance of broad assessment of symptoms, including those that fall outside the primary psychiatric diagnostic concern, in recovery-oriented clinical work.”