AIMS: To examine the association between attention-deficit/hyperactivity disorder (ADHD) symptoms and suicidal behavior in psychiatric outpatients and whether this association differs among patients with different psychiatric disorders.

METHODS: Cross-sectional data came from the Japan Prevalence Study of Adult ADHD at Psychiatric Outpatient Care (the J-PAAP study) which included psychiatric outpatients aged 18-65 years recruited from one university hospital and three general psychiatric outpatient clinics in Kitakyushu City, Fukuoka, Japan in April 2014 to January 2015 (N=864). The Adult ADHD Self-Report Scale (ASRS) Screener was used to collect information on ADHD symptoms. Reports of current and lifetime suicidal behavior were also obtained. A multivariable Poisson regression analysis was used to examine the association between ADHD symptoms and suicidal behavior.

RESULTS: After adjusting for covariates there was a strong association between possible ADHD (ASRS ≥ 14) and suicidal behavior with prevalence ratios ranging from 1.17 (lifetime suicidal ideation) to 1.59 (lifetime suicide attempt) and 2.36 (current suicidal ideation). When ASRS strata were used, there was a dose-response association between increasing ADHD symptoms and suicidal ideation and suicide attempts. Analyses of individual ICD-10 psychiatric disorders showed that associations varied across disorders and that for anxiety disorder ADHD symptoms were significantly linked to all forms of suicidal behavior.

CONCLUSION: ADHD symptom severity is associated with an increased risk for suicidal behavior in general psychiatric outpatients. As ADHD symptoms are common among adult psychiatric outpatients, detecting and treating ADHD in this population may be important for preventing suicidal behavior. This article is protected by copyright. All rights reserved.