The adverse childhood experiences—International questionnaire in clinical and at‐risk samples worldwide: A systematic review (part II)

This systematic review aimed to (1) synthesize average means and prevalence rates of adverse childhood experiences (ACEs) measured by the Adverse Childhood Experiences International Questionnaire (ACE-IQ) in clinical and at-risk samples; (2) discuss the ACE-IQ prevalence and means according to participants' gender, age (both adults and <18 years old), and geographic area; (3) map relationships between ACE-IQ scores and other outcomes; (4) detect methodological issues in studies. PRISMA guidelines were followed, searching studies in seven academic databases, including retrieval of grey literature. After screening, 23 studies were included. Results revealed the following: (1) several clinical (e.g., mood disorders and substance abuse) and at-risk (e.g., criminal and low-income) conditions were studied, with an average 4.93 mean and 81.74% prevalence of total ACEs; (2) there is a lack of data on males, with the prevalence of domestic violence and physical neglect being especially marked in minors, and no studies involving European and North-American at-risk samples; (3) ACE-IQ scores were mostly related to substance abuse and risk-taking behaviours; (4) major methodological issues were not-randomized/convenience sampling techniques and a lack of methodological information on sample and procedure. In conclusion, the ACE-IQ seems a promising tool in clinical/at-risk samples, but more studies are needed to answer all research questions.