2026 ECNP Congress

PS02-2105

Autistic-like traits and longitudinal changes in health-related quality of life among patients with bipolar disorder: a 12-month study

Tomiki Sumiyoshi — R. Yamada, H. Kunugi, S. Yoshida, T. Inagawa, K. Hattori, N. Ishihara, T. Kurashimo, S. Sumiyoshi, H. Song, A. Stickley · National Center of Neurology and Psychiatry, Department of Preventive Intervention for Psychiatric Disorders, Tokyo, Japan

2026 ECNP Congress

Objectives

Autistic-like traits are frequently observed in bipolar disorder (BD), and have been linked to poor functional outcomes, yet longitudinal evidence regarding their impact on quality of life (QOL) remains limited. This study examined whether autistic-like traits are associated with 12-month changes in health-related QOL in individuals with BD. The results provide longitudinal evidence that autistic-like traits may limit improvement in role and social functioning among individuals with BD, even when depressive symptoms improve.

Methods

The study protocol was approved by the Ethics Committee at NCNP, and written informed consent was obtained from all participants. Outpatients diagnosed with bipolar disorder (BD) receiving regular care at the Mood Disorder Center for Advanced Therapy, National Center of Neurology and Psychiatry (NCNP), Tokyo, Japan were eligible for participation. A total of 155 patients were recruited. Of these, 130 completed the baseline assessment, and 78 completed the 12-month follow-up and were included in the longitudinal analyses. Autistic-like traits were assessed using the Social Responsiveness Scale for Adults (SRS-A)[1], with participants classified into elevated- and non-elevated-traits groups. Depressive and manic symptoms were measured using the 17-item Hamilton Depression Rating Scale (HAMD-17) and the Young Mania Rating Scale (YMRS). Health-related QOL was assessed using the 36-Item Short-Form Health Survey (SF-36). Linear mixed models were used to examine longitudinal changes.

Results

At baseline, 92 of 130 participants (70.8%) exceeded the established cutoff for autistic-like traits. The mean age was 34.0 years (SD = 11.4), and the mean age at illness onset was 25.2 years (SD = 8.7). The sample comprised 55 males (42.3%). Regarding bipolar subtype, 39 participants (30.0%) were diagnosed with bipolar I disorder and 91 (70.0%) with bipolar II disorder. The mean HAMD score was 13.2 (SD = 6.1), and the mean YMRS score was 2.5 (SD = 3.3). HAMD-17 scores showed significant main effects of time and group, indicating overall improvement but persistently higher depressive symptoms in the elevated-traits group. YMRS scores showed a significant group effect only. For QOL, Physical Component Summary scores revealed no significant effects. Mental Component Summary scores improved over time without group differences. Role/Social Component Summary scores showed significant main effects of time and group, with persistently lower scores in the elevated-traits group. No group × time interactions were observed.

Conclusions

Autistic-like traits in BD are associated with persistently lower role and social functioning over time, rather than differential recovery rates. These observations may add to efforts to identify individuals at risk for poor functional recovery and inform personalized treatment strategies. To our knowledge, this is the first prospective study to demonstrate that subthreshold autistic-like traits are associated with persistently reduced role and social functioning in a clinical BD population, even when depressive symptoms improve over time. These findings may have important clinical implications for identifying individuals at risk for sustained functional impairment despite symptomatic stabilization. Specifically, our data will add to the knowledge of personalized treatment strategies that integrate targeted psychosocial interventions to support long-term outcomes.

References

  1. Bruni, T.P., 2014. Test Review: Social Responsiveness Scale–Second Edition (SRS-2). J Psychoeducational Assessment. 32, 365-369.