Konkolÿ Thege et al. BMC Psychiatry (2017) 17:164 DOI 10.1186/s12888-017-1323-1 RESEARCH ARTICLE Open Access Relationship between interpersonal trauma exposure and addictive behaviors: a systematic review Barna Konkolÿ Thege1,2,3* , Lewis Horwood1, Linda Slater4, Maria C. Tan5, David C. Hodgins1 and T. Cameron Wild6 Abstract Background: The aim of this study was to systematically summarize knowledge on the association between exposure to interpersonal trauma and addictive behaviors. Extant reviews on this association focused on a restricted range of substance-related addictions, and/or used a narrative instead of a systematic approach. Methods: Systematic searches of 8 databases yielded 29,841 studies, of which 3054 studies were included and subsequently classified in relation to study design (scoping review). A subset of observational studies (N = 181) prospectively investigating the relationship between exposure to interpersonal traumata and subsequent behavioral or substance-related addiction problems were characterized. Heterogeneity in study methodologies and types of addictive behaviors and traumatic experiences assessed precluded meta-analysis. Instead, the proportions of associations tested in this literature that revealed positive, negative, or null relationships between trauma exposure and subsequent addictive behaviors were recorded, along with other methodological features. Results: Of 3054 included studies, 70.7% (n = 2160) used a cross-sectional design. In the 181 prospective observational studies (407,041 participants, 98.8% recruited from developed countries), 35.1% of the tested associations between trauma exposure and later addictive behaviors was positive, 1.3% was negative, and 63.6% was non-significant. These results were primarily obtained among non-treatment seeking samples (80.7% of studies; n = 146), using single and multi-item measures of addictive behaviors of unknown psychometric quality (46.4% of studies). Positive associations were more frequently observed in studies examining childhood versus adult traumatization (39.7% vs. 29.7%). Conclusions: Longitudinal research in this area emphasizes alcohol abuse, and almost no research has examined behavioral addictions. Results provide some support for a positive association between exposure to interpersonal trauma and subsequent addictive behaviors but this relationship was not consistently reported. Longitudinal studies typically assessed trauma exposure retrospectively, often after addictive behavior onset, thus precluding robust inferences about whether traumatization affects initial onset of addictive behaviors. Keywords: Interpersonal trauma, Posttraumatic stress disorder, Child maltreatment, Substance abuse, Behavioral addiction, Systematic review * Correspondence: [email protected]; [email protected] 1Department of Psychology, University of Calgary, 2500 University Drive, Calgary T2N 1N4, Canada 2Research and Academics Division, Waypoint Centre for Mental Health Care, 500 Church Street, Penetanguishene, ON L9M 1G3, Canada Full list of author information is available at the end of the article © The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Konkolÿ Thege et al. BMC Psychiatry (2017) 17:164 Page 2 of 17 Background potentially modifiable risk factors for addictive behaviors, Addictive disorders are a major public health concern, as opposed to non-modifiable risk factors (e.g., natural given their high population prevalence and their associ- disasters). ated negative health, social, and economic consequences Scoping reviews aim to map rapidly the key concepts [1]. The significance of addictions may increase in the underpinning a research area, and the volume, main future because of recent changes in psychiatric diagnoses sources and types of evidence available [22]. Scoping and in public opinion, both of which have broadened reviews are often conducted before full syntheses and expert and lay conceptions beyond alcohol and other data aggregation (e.g., meta-analysis) when the relevant drugs to include a wide variety of potentially problem- literature is vast and diverse. A scoping review is par- atic behaviors (e.g., gambling, excessive sexual behavior, ticularly appropriate for reviewing the literature on the overwork, overeating [2, 3]). association between exposure to interpersonal trauma Among other genetic, personality, and psychosocial and addictive behaviors because this area is interdiscip- risk factors, psychological trauma is a commonly investi- linary, conceptually complex, and has not been reviewed gated factor hypothesized to increase vulnerability to the comprehensively before. Our specific objectives were to development of addictive disorders [4–8]. Psychological (1) systematically identify and characterize the types of traumata are negative life events or situations that have human studies conducted on this association, (2) select the potential to cause an extraordinary amount of stress longitudinal observational studies from this literature to to the individual overwhelming his/her ability to cope examine whether this body of higher-quality empirical and leaving the person in fear of death, annihilation, or research supports the idea that an association exists insanity. Although studies suggest that individuals between exposure to traumatic interpersonal events and experiencing trauma have a greater risk of developing subsequent addictive behavior, (3) provide a broad specific addictive disorders than others in the general overview on the methodologies used in prospective ob- population [9–11], a broad perspective on the state of servational studies and to suggest guidelines to improve scholarship in this area has not been provided to date. the quality of scholarship in this area, and (4) identify This is because the relevant literatures are complex (i.e., knowledge gaps and directions for future research. researchers tend to focus on specific trauma exposures, substances, and/or addictive behaviors of interest, often Methods over different parts of the life-span, sometimes among Search strategy treated populations) and interdisciplinary (i.e., study Eight databases were searched: EBSCO CINAHL Plus methods are drawn from epidemiology, psychiatry, with Full-Text, 1937-Current, Ovid EMBASE 1974- clinical and social psychology, and victimology, and Current, MEDLINE, MEDLINE In-Process & Other include both quantitative and qualitative approaches). Non-Indexed Citations 1946-Current, ProQuest PI- To our knowledge, this diversity has not yet been LOTS 1871-Current, Ovid PsycINFO 1806-Current, systematically characterized. Moreover, extant reviews Scopus 1960-Current, and EBSCO Violence and Abuse focus on a small number of substance-related addictions, Abstracts 1984-Current. Searches were completed on specific age groups or sexes, and/or use a narrative June 10, 2014. rather than a systematic approach [5, 8, 12–15]. A Search terms were initially generated by the entire re- systematic overview of the methods and empirical findings search team, from which a preliminary set of subject in this area is also needed because of the large amount of headings were identified using the relevant electronic data accumulated and in light of inconsistent findings bibliographic databases. Then, the first 10 records of a observed across studies [1, 16–19]. separate search were scanned for each subject heading To address these issues, we conducted a systematic for further possible keywords. The resulting list was scoping review [20, 21] of the literature on associations reviewed, corrected, and completed by the research team between exposure to trauma and addictive behaviors in (e.g., adding different spelling variations of certain which a deliberately broad frame was used to include a terms). Table 1 presents the final version of the search range of interpersonal traumata and a wide variety of term list. Guided by this list, two professional librarians substance-related and behavioral addiction outcomes. (LS, MT), with expertise in conducting systematic lite- As our goal was to provide a comprehensive overview rature review searches, developed a search strategy of the literature, we considered both the potentially that included controlled vocabulary (where available) traumatic events– (e.g., report of childhood sexual abuse) and free-text terms representing the major concepts and the trauma-related psychological symptoms (e.g., contained in the review topic. Terms were combined as posttraumatic symptoms after a physical assault) concep- follows: (substance use OR excessive behavior terms) tualizations of traumatization. Our rationale for focusing AND (trauma terms) AND (study design filter). Searches on interpersonal traumata was that these represent were limited to English language publications. No date Konkolÿ Thege et al. BMC Psychiatry (2017) 17:164 Page 3 of 17 Table 1 List of general search terms to identify relevant studies Trauma Adverse experience, Emotional trauma, Maltreatment,