The clinical picture of late-onset PTSD: A 20-year longitudinal study of Israeli war veterans Danny Horesh a,n , Zahava Solomon b , Giora Keinan c , Tsachi Ein-Dor d a Department of Psychiatry, New York University, New York, NY 10016, USA b The Bob Shapell School of Social Work, Tel Aviv University, Tel Aviv, Israel c Department of Psychology, Tel Aviv University, Tel Aviv, Israel d School of Psychology, Interdisciplinary Center (IDC), Herzliya, Israel article info Article history: Received 15 January 2012 Received in revised form 5 December 2012 Accepted 6 December 2012 Keywords: PTSD Psychopathology Military psychiatry abstract Delayed-onset PTSD has been under medico-legal debate for years. Previous studies examining the prevalence and clinical characteristics of delayed-onset PTSD have yielded inconclusive findings. This study prospectively examines the prevalence and clinical picture of late-onset PTSD among Israeli war veterans. It also evaluates whether or not late-onset PTSD erupts after a completely non-symptomatic period. 675 Israeli veterans from the 1982 Lebanon War, with and without antecedent combat stress reaction (CSR), have been assessed 1, 2 and 20 years post-war. They were divided into 4 groups, according to the duration of delay in PTSD onset. Participants completed self-report questionnaires tapping psychopathology, combat exposure and socio-demographics. 16.5% of the veterans suffered from late-onset PTSD. A longer delay in PTSD onset was associated with less severe psychopathology. Also, CSR was associated with a shorter delay in PTSD onset. Finally, the vast majority of veterans already suffered from PTSD symptoms prior to late PTSD onset. Our results offer further validation for the existence of delayed-onset PTSD. Delayed-onset PTSD appears to be a unique sub-type of PTSD, with an attenuated clinical picture. In addition, delayed-onset PTSD may be the result of an incubation process, wherein symptoms already exist prior to PTSD onset. & 2012 Elsevier Ireland Ltd. All rights reserved. 1. Introduction The effects of combat may range from acute, short-term reac- tions (e.g. combat stress reaction; CSR) to chronic, long-term psychiatric sequelae (e.g. PTSD). In most cases, PTSD erupts follow- ing a relatively short period after the occurrence of the traumatic event. However, when PTSD first erupts at least 6-months post- trauma, this is defined by DSM-IV-TR (American Psychiatric Association, 2000) as delayed onset PTSD (DPTSD). For many years, there has been substantial medico-legal debate regarding the validity of DPTSD. In a reality where victims may benefit financially from being labeled as ‘‘post-traumatic’’, delayed onset of PTSD is often regarded with suspicion. Thus, some have argued that seemingly new cases of PTSD are actually manifestations of malingering (Smith and Frueh, 1996). Others (e.g., Pary et al., 1986) have claimed that in many cases it is not the disorder that is delayed, but rather the seeking of treatment or the identification of post-traumatic symptoms—whether by the victim, by his/her family or by the medical authorities. According to this view, the post-traumatic disorder may have been active for a significant period of time without ever being properly diagnosed. Despite the voices questioning the validity of DPTSD, a growing body of literature supports the existence of this phenomenon. In fact, DPTSD was found among victims of various kinds of trau- matic events, such as motor vehicle accidents (Mayou et al., 1993), natural disasters (Green et al., 1990), incest (Green et al., 1995) and combat (Nitto, 2001). In addition, a meta-analysis of prospec- tive DPTSD studies (Smid et al., 2009) has shown convincing evidence supporting the validity of this phenomenon, as well as specific factors associated with it (i.e., military combat exposure, western cultural background, lower cumulative PTSD incidence). Close scrutiny of DPTSD research has revealed inconsistent find- ings. Considerable differences in the rates of DPTSD exist, with estimates ranging from 0% (Epstein, 1993) to over 60% (Op den Velde et al., 1993; Solomon et al., 2012). These differences in prevalence may be attributed, among other things, to significant variance and lack of standardization in the definitions of DPTSD across studies (for a comprehensive review, see Andrews et al., 2007). One of the aims of the present study is to assess the long-term prevalence of DPTSD, using a prospective longitudinal design with several follow-ups. Contents lists available at SciVerse ScienceDirect journal homepage: www.elsevier.com/locate/psychres Psychiatry Research 0165-1781/$ - see front matter & 2012 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.psychres.2012.12.004 n Corresponding author. Tel.: þ1 646 754 4804x44804. E-mail address: Danny.Horesh@nyumc.org (D. Horesh). Please cite this article as: Horesh, D., et al., The clinical picture of late-onset PTSD: A 20-year longitudinal study of Israeli war veterans. Psychiatry Research (2013), http://dx.doi.org/10.1016/j.psychres.2012.12.004i Psychiatry Research ] (]]]]) ]]]–]]]