Association of symptom severity, insight and increased pharmacologic side effects in acutely hospitalized patients with schizophrenia

Background: Many studies have shown that more severe symptoms and poorer insight are associated with poor treatment compliance in schizophrenia while severe symptoms may result in higher medication dosages. Since pharmacologic side effects may accompany greater medication compliance and higher medication dosage, the relationship between symptoms, insight and side effects deserves study.

Methods: In this study, 174 inpatients diagnosed with schizophrenia were assessed during the week before hospital discharge from a large psychiatric hospital in Guangzhou, China. Symptoms were measured by the Positive and Negative Syndrome Scale for Schizophrenia (PANSS). Insight was assessed by the Insight and Treatment Attitudes Questionnaire (ITAQ). Pharmacologic side effects were assessed by the Treatment Emergent Symptoms Scale (TESS). Bivariate and multivariate regression models were used to examine the relationship of symptoms, insight and the interaction between the two, to the severity of side effects.

Results: As expected, the PANSS total score was significantly associated with poorer ITAQ scores and with more severe side effects, and on multivariate analysis both higher PANSS and lower ITAQ scores were associated with more severe side effects. Stepwise multiple linear regression analysis showed that the model with the PANSS total score alone explained 3.4% of the variance in side-effect scores, while adding the ITAQ increased the explained variance to 11.8%. Analysis of the interaction of symptoms and insight showed that patients with both more severe symptoms and high insight had the most severe side effects (B=.006, p=.008, R(2)=15.4%).

Conclusion: More severe symptoms and greater insight among schizophrenic inpatients were both significantly if modestly associated with more severe pharmacologic side effects, the former presumably because of the need for higher doses of medication and the latter because of greater medication compliance. In addition, patients with both more severe symptoms and greater insight were even more prone to pharmacologic side effects than others presumably reflecting higher doses and higher compliance. Clinicians treating highly symptomatic but insightful patients, i.e. those most likely to need and to adhere to prescribed medications, may need to be especially vigilant about side effects.