Schizophrenia significantly impacts social functioning, often leading to reduced work hours. Effective pharmacological therapy is crucial for managing the disorder and improving social functioning. However, adherence to treatment guidelines among psychiatrists varies. This study aimed to determine if better adherence to guidelines, as measured by the Individual Fitness Score (IFS), correlates with increased work hours in patients with schizophrenia. The IFS quantifies the degree to which a psychiatrist's prescription adheres to the Japanese Society of Neuropsychopharmacology's guidelines for pharmacological therapy. The hypothesis was that better adherence (higher IFS scores) would be associated with longer work hours. Prior research has shown that guideline-compliant treatment is linked to improved quality of life and reduced symptom severity. However, the association between adherence and a specific social functional outcome like work hours remained unclear, thus motivating this study.

The literature extensively documents the social dysfunction experienced by individuals with schizophrenia, including social withdrawal, impaired social cognition, social anxiety, and deficits in social skills. These dysfunctions can stem from positive and negative symptoms, as well as anxiety related to social interaction. Pharmacological therapy, primarily using antipsychotic medications, plays a vital role in managing these symptoms. However, polypharmacy, the concurrent use of multiple medications, is common and carries increased risks of side effects. National guidelines, such as those from the American Psychiatric Association and the National Institute for Health and Care Excellence, recommend careful evaluation of polypharmacy versus monotherapy, generally favouring monotherapy when feasible to minimize adverse effects. The Japanese Society of Neuropsychopharmacology also advocates for antipsychotic monotherapy to avoid polypharmacy with medications like anticholinergics and benzodiazepines. While these guidelines exist, the degree of adherence in clinical practice requires further clarification. Initiatives like the Japanese EGUIDE project aim to improve guideline adherence, and tools like the IFS are being developed to measure the gap between guidelines and actual clinical practice. Previous research using the IFS showed links between guideline adherence and better quality of life and milder psychiatric symptoms. This current study extends this work by specifically investigating the relationship between adherence and work hours, a crucial aspect of social functioning.

This study involved 286 in- and outpatients with schizophrenia from Osaka University Hospital, diagnosed using DSM-IV criteria and the SCID. Treatment-resistant schizophrenia (TRS) was defined based on Japanese criteria: failure to achieve a GAF score of 41 or higher after at least four weeks of treatment with two or more adequate doses of independent antipsychotics (including one or more atypical antipsychotics), or the use of clozapine or ECT. The IFS, developed by Inada et al., measured psychiatrists' adherence to guidelines. The IFS ranges from 0 to 100, with 100 indicating optimal adherence to guidelines (monotherapy for non-TRS and clozapine or ECT for TRS). Work hours were assessed using the Social Activity Assessment (SAA), which considers work for pay, work at home, and student activities over the preceding 12 weeks. Spearman's rank correlation coefficient was used to analyze the relationship between IFS and work hours due to the non-normal distribution of the data. Analysis was performed on the entire sample and separately on patients with and without TRS. Regression analysis further explored the influence of confounding factors such as age, sex, education, age at onset, illness duration, and symptom severity. The study was approved by relevant ethics committees, and written informed consent was obtained from all participants.

The study included 286 patients (mean IFS = 52.6 ± 39.1; mean work hours = 10.7 ± 16.3). A significant positive correlation was observed between IFS and work hours (rho = 0.18, p = 2.15 x 10^-3), indicating that higher adherence to guidelines was associated with longer work hours. Among the 40 TRS patients, most (85%) did not work at all. Even after excluding TRS patients, the positive correlation between IFS and work hours remained significant in the non-TRS group (rho = 0.19, p = 3.32 x 10^-3). Regression analysis showed that the association between IFS and work hours remained significant after adjusting for confounding factors except for negative symptoms (p = 0.064). The positive relationship between adherence and longer working hours was also found to be significant when the TRS diagnosis was included as a covariate in the analysis of all the patients (beta = 0.16, p = 4.74 × 10⁻³).

This study provides the first evidence of a correlation between guideline-based pharmacological treatment (as measured by IFS) and work hours in schizophrenia patients. The findings support the hypothesis that better adherence to guidelines is associated with improved social functioning, specifically work hours. The significant correlation persists even after controlling for confounding variables such as age, sex and symptom severity, except for negative symptoms which showed a p-value of 0.064. The results suggest that interventions aimed at improving guideline adherence, such as the EGUIDE project, may be effective in improving functional outcomes. It's important to note that TRS patients, who are often characterized by poor treatment response, had significantly shorter work hours, highlighting the complexity of treatment adherence and its relation to functional outcomes. However, the positive correlation between adherence and work hours remains significant even after excluding this group.

This study demonstrates a positive correlation between psychiatrists' adherence to pharmacological treatment guidelines and work hours in patients with schizophrenia. Improving adherence through educational and training initiatives is crucial for improving functional outcomes. Future longitudinal studies with larger sample sizes and controlling for social and environmental factors, along with exploring the mediating effects of specific factors such as cognitive function, are needed to further clarify the relationship and establish causality. Incorporating comprehensive indicators, such as the IFS, into future research is also encouraged to better capture the complexity of this interaction.

This study used a cross-sectional design, which limits the ability to establish causal relationships between guideline adherence and work hours. The study relied on prescription information at a single assessment point, which might not reflect long-term treatment patterns or response. Lack of information on psychosocial interventions, family support, and detailed social background could have influenced the findings. The sample might not be fully representative of the wider population of schizophrenia patients. Additional research is required to address these limitations and to provide more conclusive evidence.