The major finding of this study was that the entire sample suffered at least one ACE, and that the COA with “risky drinking” had a broader range of patterns of adverse childhood experiences and a higher frequency than the non-risky drinking group, including physical abuse, community violence and collective violence. These factors had a graded relationship with “risky drinking” in the COA. Physical abuse, community violence and collective violence showed a two to 11- fold increase in “risky drinking” in the adult COA before controlling for the covariate of comorbidities. Community violence was still associated with a 14- fold increase after controlling for the covariates. In addition, we found that “risky drinking” group enjoyed self-drinking more, “non-risky drinking” group hated self-drinking more.
In this study, we found that all of the COA reported at least one ACE, but there was no significant difference in the number of ACEs between two groups, which could indicate that there was a strong association between alcohol-abusing parents and ACEs in children. One of the reason was that living with intoxicated parents probably led to children facing dysfunctional parenting, emotional and physical neglect and/or abuse, which will affect parent-children bonding and their feeling of safety [21, 28,29,30]. In addition, alcohol-using parents appeared to pass on drinking patterns through being a negative role model for responding to life difficulties or conflicts [31, 32]. Therefore, COA might learn maladaptive responses in their school and social relationships, witch was more strongly related to the content nature of ACEs, rather than the number of ACEs. Children might also pursue self-medication to release their negative emotions, such as fear, shame, phobia, anxiety and/or depression. Self-medication included the use of psychoactive substances and other risky behaviors [33]. Additionally, as they lived in unsafe surroundings, more physical abuse or community and collective violence would be experienced or witnessed by the COA [31, 32].
It was shown in this study that in the “risky drinking” group, community violence, domestic violence, emotional abuse, and physical abuse were the top four adverse experiences, and in the “non-risky drinking group”, domestic violence, emotional abuse, community violence and physical neglect had the highest prevalence, which was similar to findings in Hong Kong [16]; however, these data contrasted with the results from the US and Canada where there appeared to be higher exposure to household dysfunction (including neglect and abuse) rather than violence [34,35,36]. The high level of domestic violence toward both family members and COA reflected a feature of a different culture, such as rigid gender roles, endorsement of physical punishment and absolute parental authority [16, 37,38,39]. Community violence showed differences, and this factor might be added to the other ACEs that already influenced the health of COA. Community violence reflected a harsher living environment, and this finding was in accordance with the results of another study that showed the positive relationship between a disadvantaged community and risky drinking [40]. Part of the condition described as community violence and collective violence, such as “being threatened with a gun in real life, deliberate destruction of your home or having been beaten up by soldiers, police, militia, or gangs”, was not frequent in Chinese society; therefore, the understanding of community violence was different in Western and Eastern countries. The finding that the rest of the ACEs, excluding community violence, showed no significant impact on “risky drinking” might be due to the high rate of ACEs in both groups, and COA who showed “risky drinking” experienced more adverse childhood experiences than the general population.
In this experiment, we found that there were significant differences in attitude to self-drinking between the two groups, in addition to the significant differences in ACEs, Other studies had shown that ACEs could affect the acquired changes in brain structure and function, personality development, and interpersonal relationships of individuals [41]. In a study on adolescent drinking attitudes, they found that lack of parental presence was a risk factor for alcohol consumption among adolescents [42]. The possible reason was that adolescents were closely connected with their parents. According to social learning theory, adolescents were willing to learn behaviors from those around them [43]. Therefore, when individuals suffer more ACEs, they prefered to deal with the problem through drinking, leading to difference in attitude to self-drinking between two groups.
Regarding the comorbidities, the “risky drinking” group was more likely to suffer current depressive episodes, non-alcohol psychoactive substance use disorder and bulimia nervosa than the “non-risky drinking” group. It was difficult to determine the chronological sequence of “risky drinking” and other mental health problems because of the cross-sectional design of this study. This result was in accordance with a meta-analysis, which showed that externalizing problems in some studies and depression tended to be positively associated with alcohol use, but there was no clear association between alcohol problems and anxiety [44]. A potential explanation was that people who had a tendency toward behavioral disinhibition were more likely to be involved in restricted actions, especially those who had experienced adverse and high-risk living environments [45,46,47]. Another mechanism was related to the presence of an internalizing pathway, which was also known as “self-medication” or “tension reduction” [48], as previously elaborated. COA often lacked adaptive social skills when facing difficulties; consequently, they were more likely to have mental health problems, including “risky drinking” and depression [30, 49]. In a study conducted by our team in 2011, it was shown that most alcoholics who had a comorbidity of social anxiety declared that they had social anxiety before drinking and that drinking decreased the anxiety symptoms [50]. Comorbidities could interact with risky drinking or be a negative outcome of ACEs. In cross-sectional studies, comorbidities should be controlled as covariates in the logistic regression model.
In this study, through self-selection, most of the respondents were young females who were highly educated, had a stable job and had a relatively high income. This seemed counterintuitive and made the findings even more striking than if the group was marginal regarding their education, employment and income. It might be that females were more likely to be aware of fathers’ drinking problems and had a curiosity to know more about what is wrong with their father. In the “risky drinking” group, there were more males. One possible reason was that sons of alcoholics were more sensitive to the euphoric and stimulatory effects of alcohol [12]. They initiated repeated drinking to avoid negative hedonic effects [12]. Thus, sons of alcoholics were likely to develop alcohol use problems.
This study also had the following deficiencies. Although a structured interviewing tool was used to assess the participants, we gathered the history of the probands mainly through the reports of the COA. The exclusion of maternal alcoholics might have risked the introduction of biases to the findings, but as there was a significant discrepancy between the prevalence of male and female alcohol dependence in China (6.6% vs 0.2%) [51], it might not be a major problem for this study in the context of Eastern culture. There existed selection bias in that the participants in this study generally had a high education and stable employment, which were potentially protective factors, and they had a high percentage of ACEs and comorbidities, which might be risk factors. In the future, studies should expand the study population to be more representative of the general public. The ACE measure was used worldwide, but it was still limited regarding the collection of duration, frequency and onset of adverse experiences. As it was a case–control study, we could make the assumption of a causal relationship between risky drinking in COA and ACEs, but if we wanted to clarify the cause and result, future, larger sample cohorts with strict control of confounds should be developed.
The findings of this study are meant to help clinicians focus more on the family of COA and, for the first time in our country, provide data and a theoretical basis for the needed healthcare, psychological support and societal understanding. Schools and medical professionals need to perform more evaluations of the negative childhood experiences of COA and provide interventions for COA. The implications of this study are particularly strong for Asian cultures where awareness and prevention efforts lag.