title: Comorbid atypical autistic traits as a potential risk factor for suicide attempts among adult depressed patients: a case-control study.
abstract: BACKGROUND
  The present study aims to examine if autism spectrum disorder (ASD) is a risk factor for suicide attempts among adult depressed patients and to elucidate the characteristics of suicide attempts in adult depressed patients with ASD.
  
  
  METHODS
  We conducted a case-control study. Subjects consisted of 336 retrospectively recruited first-time visit patients to our outpatient clinic with a current major depressive episode; 31 of the 336 patients had attempted suicide. The demographic backgrounds (i.e., age, gender, personal/family history of suicidality); specific psychopathology like bipolarity, agitation, and psychotic features; and comorbidity such as physical diseases, alcohol abuse, cluster B personality disorder, and ASD including pervasive developmental disorder not otherwise specified (PDD-NOS) were examined as potential risk factors for suicide attempts. We compared these variables between the suicide attempters and non-attempters. In addition, we compared suicide attempters to non-attempters within the ASD group and non-ASD group. Binary logistic regression analysis was performed using the significant independent variables from the comparisons between the suicide attempters and non-attempters, and the odds ratios (OR) and 95% confidence intervals (CI) were calculated.
  
  
  RESULTS
  Logistic regression analysis demonstrated that agitation during a depressive episode (OR = 7.15, 95% CI = 2.88-17.74), past suicidal behaviors (OR = 4.32, 95% CI =1.70-10.98), and comorbid PDD-NOS (OR = 4.04, 95% CI = 1.20-13.54) were significantly associated with suicide attempts. The most prevalent suicidal method was drug overdose (59.1%) among non-ASD attempters while hanging was the most prevalent (44.4%) in ASD attempters.
  
  
  CONCLUSIONS
  Depressed adults with comorbid atypical autistic traits are at higher risk for suicide attempts and may engage in methods that are more lethal.
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa 903-0215 Japan.
authors.forename: Kiyoharu
authors.initials: K
authors.lastname: Takara
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa 903-0215 Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kondo
keywords: Adult; Atypical; Autism spectrum disorder; Depressive episode; Pervasive developmental disorder-not otherwise specified; Risk factor; Suicide attempt; Suicide methods