Partial mediator role of physical abuse on the relationship between attention-deficit/hyperactivity disorder symptoms and severity of dissociative experiences in a sample of inpatients with alcohol use disorder

Abstract

Aim:

This study aimed to evaluate the relationship of attention-deficit/hyperactivity disorder (ADHD) symptoms with dissociative experiences, and the mediator role of childhood traumas on this relationship, while controlling the effect of depression in alcohol use disorder (AUD).

Settings and Design:

It was a hospital-based, cross-sectional study.

Materials and Methods:

One hundred and ninety inpatients with AUD were evaluated with the Beck Depression Inventory, the Adult ADHD Self-Report Scale (ASRS), Childhood Trauma Qestionnaire, and Dissociative Experiences Scale (DES).

Statistical Analysis:

One-way ANOVA, Chi-squared test, and hierarchical linear regression model were performed.

Results:

The ratio of those who receive 10 points or less from DES was 26.8%, those who receive points between 11 and 30 was 45.3%, and those who receive more than 30 points was 27.9%. The latter group that was considered as a group with high risk of dissociative disorder had higher scores from depression, childhood trauma, and ADHD scores than the other groups. Rate of those with high probability of ADHD was higher among this group. ASRS total score and inattentive subscale scores were moderately (r = 0.552 and r = 0.547, respectively) and hyperactive/impulsive subscale was mildly (r = 0.430) correlated with DES score. Severity of ADHD was related with the severity of dissociative symptoms, and physical abuse had partial mediator effect on this relationship, even after controlling the depressive symptoms.

Conclusions:

These findings demonstrate that the presence of severe IN symptoms is an important factor related with dissociative tendency in AUD population with a history of physical abuse.

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is among the most common childhood-onset behavioral disorders characterized by hyperactivity/impulsivity (HI) and inattention (IN) symptoms.[1] In half of the cases, the symptoms spontaneously remit by early adulthood, whereas in others, the symptoms persist from childhood to adolescence and adulthood.[2] Due to their symptoms that potentially disrupt one's ability to function and carry out personal responsibilities,[1] individuals with ADHD experience more difficulties while coping with problems through their life and they became more vulnerable to use alcohol and develop alcohol use disorder (AUD).[3,4] Prevalence of possible ADHD among individuals with AUD is between 21% and 23.1%.[5,6,7,8] Individuals with ADHD and AUD comorbidity are at greater risk for more negative outcomes,[9] and ADHD is associated with early relapse among those with AUD.[10]

According to the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), “dissociation” is used to identify the “disruption of/and or discontinuity in the normal integration of consciousness, memory, identity, emotion, perception, body representation, motor control, and behavior.”[11] Dissociative experiences range between normal (e.g., absorption/imaginative symptoms) and pathological dissociative experiences (e.g., depersonalization/derealization, dissociative amnesia).[12,13,14] Dissociation is not only a disorder on its own, but also it accompanies several psychiatric disorders as a comorbid disorder or confounding factor, such as AUD.[15] Rates for high levels of dissociative experiences (scores of 30.0 or above from Dissociative Experiences Scale [DES]) in Turkish AUD inpatients were reported as 26.1%[15] and 29.0%[16] in previous studies. It was also suggested that concurrence of AUD and dissociation was related with higher comorbidity (e.g., major depression)[15] and additional clinical problems (e.g., suicidality and self-mutilation),[15,17] more severe course of the illness, and a poor treatment outcome.[18] Dissociation is also associated with childhood trauma among patients with AUD.[19,20,21]

Previous studies demonstrated that ADHD symptoms in childhood are related with both dissociative disorder in childhood[22] and dissociative tendency in adulthood.[23] This may suggest that the association between ADHD symptoms and dissociation in abused children[22] may also be true for adults with a history of child abuse, and that ADHD symptoms in childhood might be a precursor to dissociation in some men.[23] Consistent with these findings, a study conducted in adolescents reported that the severity of dissociative experiences was significantly higher in ADHD group than groups with other diagnoses.[24] Furthermore, in another study conducted among adolescents with dissociative disorder, it was found that 60% of individuals had ADHD.[25] Although these studies suggest an apparent relationship between severity of dissociative experiences or dissociative disorders and severity of ADHD symptoms or ADHD, unfortunately this relationship was not studied in adult populations with high risk of these variables, such as patients with AUD.

History of childhood abuse and neglect has been demonstrated as a common phenomenon among patients with AUD,[26,27] including prospective studies.[28,29] In a previous study, more than half of the Turkish patients with substance use disorder (56.1%) reported to experience a childhood emotional, physical, or sexual abuse, and/or physical or emotional neglect.[30] On the other hand, ADHD is associated with high levels of risk-taking behavior and impulsivity that could lead to traumatic events,[31,32] and traumatic experience during childhood is known to be significantly associated with ADHD symptoms in adulthood.[33,34] Childhood emotional and physical abuse was also correlated with the severity of adulthood symptoms of ADHD.[35]

Studies considered that dissociative experiences,[15] ADHD,[36] and childhood trauma[30] were all related with AUD. Childhood trauma experiences are also associated with the co-occurrence of AUD and dissociative experiences[15] or ADHD.[37] Although these are common disorders in populations with AUD, generally, there is an underassessment or underrecognition of ADHD,[38,39] childhood trauma,[40] and dissociative experiences[15] by clinicians among patients in an AUD treatment program. Thus, in this study, we wanted to evaluate the relationship of ADHD symptoms and dissociative experiences, and the mediating role of childhood trauma on this relationship among male inpatients with AUD. Since previous studies showed that the severity of depressive symptoms might also be related with the severity of ADHD,[41] childhood trauma,[42] or dissociative experiences,[15] we also aimed to control the effect of these depressive symptoms on the relationship between ADHD symptoms and severity of dissociative experiences.

MATERIALS AND METHODS

Subjects

The study was conducted in Bakirkoy Training and Research Hospital for Psychiatry, Neurology and Neurosurgery, Alcohol and Drug Research, Treatment and Training Center in Istanbul, between September 2014 and April 2015. It is a specialized center for substance use disorders with 84 inpatient beds (36 beds for AUD) and accepts patients from all over Turkey. The study was approved by the Ethical Committee of the institution. Patients' written informed consent was obtained after the study protocol was thoroughly explained.

One hundred and ninety consecutively admitted male alcohol-dependent inpatients were considered for participation in the study. All participants met the DSM-5[11] diagnostic criteria for AUD. Since depressive symptoms and depression are common during withdrawal period, it is suggested to wait at least 3–4 weeks for certain clinical evaluation.[43] Thus interviews with the study group were conducted 3-4 weeks after the last day of alcohol use.

Measures

The Beck Depression Inventory

Symptoms and severity of depression were evaluated using the Beck Depression Inventory (BDI).[44] Turkish version of BDI was validated by Hisli.[45]

Adult attention-deficit/hyperactivity disorder self-report scale

Adult attention-deficit/hyperactivity disorder self-report scale (ASRS) is a short, 18-item self-report scale (9 items for IN and 9 items for HI) which directly relates to the DSM fourth Text Revision diagnostic criteria for screening of ADHD in adults (ASRS-v1.1; 10).[46] These 18 statements related to aspects of ADHD are rated on a 5-point Likert scale from “0-never” to “4-very often.” The 6-item screening version of ASRS has also been shown to outperform the full 18-item version in sensitivity (68.7% vs. 56.3%) and specificity (99.5% vs. 98.3%) in American general population.[47,48] Turkish version of the scale was validated in a sample of university students previously.[49] Psychometric characteristics of the Turkish version have also been found to be satisfactory in a sample of patients with AUD.[36] In the present study, 18-item version of ASRS was used and the severity of each dimension (IN and HI) was measured by summing the scores of each 9 items per subscale. Nevertheless, ASRS is a screening test and it could not replace a clinical diagnosis, so the clinician must evaluate the ASRS-positive patients with gold standard tests to be sure about the ADHD diagnoses.

The childhood trauma questionnaire (28-item version)

The childhood trauma questionnaire-28 (CTQ-28) is a retrospective self-report instrument that inquires childhood maltreatment in five areas: emotional abuse, physical abuse, sexual abuse, emotional neglect, and physical neglect. It comprises 28 items about childhood experiences (before the age of 18) that were rated on a 5-point Likert-type scale (“never true” to “very often true”). Twenty-five items are related to five subscales (five items per subscale) whereas remaining three items evaluated the “minimalization” control scale and they are not included into the total CTQ score. Reliability and validity of the CTQ, including its stability over time, convergent and discriminant validity with structured trauma interviews, and corroboration using independent data, has been documented.[50,51,52] The CTQ-28 was validated in Turkish populations.[53]

The dissociative experiences scale

The DES is a 28-item self-report scale.[54] Respondents are asked to rate various dissociative experiences that are occurring in their daily life when they are not under the influence of alcohol or drugs. The Turkish version of the scale has reliability and validity as high as those of the original form,[55] with a good Cronbach's alpha (0.95) in the present study as well. Although it is not possible to ensure whether the patients only responded to dissociative experiences that are not under the influence of alcohol or drugs, this scale was successfully used in previous studies among AUD patients, with similar mean (22.9, standard deviation = 18.0) and rates for risk grouping as high (26.1%), low (51.4%), and no (22.5%) risk as found in the present study.[15]

Data analysis

The statistical package SPSS 17.0 for Windows (SPSS, 278 Chicago, IL, USA) was used for all the analyses. One-way ANOVA was used to compare three groups according to current age, duration of education, and scale scores. Tukey's honest significant difference test was used as a post hoc test. Categorical sociodemographic variables were compared by means of the χ² statistics. Odds ratios (ORs) and 95% confidence intervals were calculated. Taken the severity of dissociative experiences as dependent variable, hierarchical (depressive symptoms, ADHD symptoms, and childhood trauma types) linear regression model was performed. For all statistical analyses, P values were two tailed, and differences were considered significant at P < 0.05.

RESULTS

The ratio of those who receive 10 points or less from DES was 26.8%, those who receive points between 11 and 30 was 45.3%, and those who receive more than 30 points was 27.9%. The latter group was considered a high-risk group for dissociative disorder. This group had higher scores for depression, childhood trauma, and ADHD questionnaires compared to the other groups. Age, education, marital status, and employment did not differ between the groups. Rate of those with high probability of ADHD (n = 35, 18.4%) was higher among the groups with high risk of dissociative disorder [Table 1]. Mean DES score was higher among those with high probability of ADHD (40.13 ± 21.85) than the group with low probability of ADHD (19.88 ± 14.70) (t = −5.22, P < 0.001) (not shown).

Table 1.

Sociodemographic variables and scale scores according to Dissociative Experiences Scale risk clusters

ASRS total score and IN subscale scores were moderately correlated with DES score (r = 0.552 and r = 0.547, respectively), whereas HI subscale was mildly correlated with DES score (r = 0.430) (not shown).

MANCOVA with IN and HI subscales of ASRS as dependent variables and childhood trauma types as covariates showed that physical abuse predicted (mean square = 155, 548, df = 1, F = 4593, P = 0.034, R² = 0.171, adjusted R² = 0.135) the severity of IN symptoms (not shown). Taking the severity of dissociative experiences as a dependent variable, depression score was entered as an independent variable in Step 1. In Step 2a, ASRS-18 score, whereas in Step 2b, IN and HI subscales of ASRS were entered as independent variables instead of ASRS-18 score. Finally, in Step 3, childhood trauma types were entered as independent variables. Severity of ADHD (particularly IN dimension) predicted the severity of dissociative symptoms, together with depressive symptoms and physical abuse [Table 2].

Table 2.

Predictors of Dissociative Experiences Scale score in linear regression model

DISCUSSION

Consistent with previous studies conducted among patients with AUD, rates for high risk of dissociative disorder[15,16] and ADHD[5,6,7,8] were found to be 27.9% and 18.4%, respectively, in the present study. The main finding of the present study is that severity of ADHD symptoms, particularly IN symptoms, is related with the severity of dissociative experiences, while the severity of physical abuse has a partial mediator effect on this relationship, together with the severity of depressive symptoms among male inpatients with AUD. A previous study demonstrated that ADHD symptoms and dissociative disorder frequently coexist in abused children, suggesting that dissociative disorder may increase the incidence of apparent ADHD symptoms.[22] Another study demonstrated that childhood ADHD symptoms are associated with adulthood dissociative tendency, although they may be related to a childhood physical or sexual abuse.[23] Our results suggest an increased risk for dissociative tendency with ADHD, but this relationship cannot be explained solely by increased rate of trauma in this population. Alternatively, relationship between the severity of ADHD symptoms and dissociative experiences may involve bidirectional pathways and multiple mediating variables such as environmental or genetic factors. Nevertheless, at the minimum, these findings suggest that the severity of IN symptoms is related with the severity of dissociative experiences, and together with severe depressive symptoms, physical abuse seems to have a partial mediator role in these relationships among male inpatients with AUD.

Increased likelihood of exposure to trauma is closely associated with lifetime diagnosis of ADHD, problems with hyperactivity, difficult temperament during childhood, and antisocial behavior.[56] In a previous study on childhood physical abuse, when considered alone, it was associated with highest increased ORs for ADHD (OR = 5.32).[57] ADHD may contribute to stressful environment in house that in turn provokes childhood maltreatment such as physical abuse and later onset of psychiatric disorders.[57] History of childhood trauma is associated with an increased risk of lifetime psychiatric comorbidities such as mood disorders, anxiety disorders, or suicide attempts,[58] and it is also possible that ADHD symptoms confer vulnerability for later depressive symptomatology following childhood trauma.[59] Since dissociation is a well-known strategy to alleviate painful emotions,[60,61] at that point, dissociation may serve as a defense mechanism against intolerable, trauma-associated memories and feelings in these individuals[61] with a history of childhood trauma.[62] In a previous study conducted among male inmates, a significant association was found between childhood ADHD symptoms and current dissociative tendency.[23] When these are taken into consideration, we may speculate that, because of ADHD symptoms in childhood, these children or adolescents may be frequently abused by others, which in turn may be the cause of depression and higher severity of dissociative experiences in adulthood. Nevertheless, it must be considered that current ADHD symptoms were evaluated in the present study, not symptoms in childhood.

Association of childhood trauma and dissociation among patients with SUDs has been investigated in previous studies.[20,21] Childhood emotional abuse reported to predict dissociation among patients with AUD.[19] Similarly, high dissociative tendency was reported to be related with severe childhood trauma (all trauma types) in Turkish inpatients with AUD, and also severity of childhood trauma predicted the severity of dissociative experiences in this population.[21] In the present study, although severity of all trauma types, other than sexual abuse, was higher among those with high dissociative experiences, only the severity of physical abuse predicted the severity of dissociative experiences. Thus, evaluation of all trauma types is important to understand the impact of trauma, to make treatment and prevention plans, and also to identify the association between childhood abuse and dissociation in patients with AUD. It was also hypothesized that dissociation mediated the relationship between childhood abuse and AUDs.[63] Related with this hypothesis, the concept of chemical dissociation was suggested, which assumes that victimized individuals with decreased capacities to dissociate may use alcohol to produce dissociative-like states.[64]

Childhood abuse in humans cannot be studied naturally by randomized controlled trials, but adoption and twin studies reported that childhood abuse might represent a casual risk factor for ADHD-like traits.[65,66] Childhood trauma leads to neurocognitive changes such as working memory, executive and emotional control,[67] inhibitory network and response,[68] or epigenetic changes[69] associated with ADHD. We hypothesized that children with ADHD are more trauma prone due to their symptoms, but findings also suggest that childhood maltreatment is an environmental risk factor for ADHD both in children[57] and adults.[33] From this point of view, childhood abuse itself may also increase the likelihood of the development of ADHD symptoms,[33] and it may be suggested that dissociative symptoms due to childhood trauma may be more frequent in patients who developed ADHD symptoms.

The present study has some limitations. First, because this study is cross-sectional in structure, it cannot address the casual relationship between ADHD, trauma, and dissociation. Second, all participants are treatment-seeking male patients and it is not possible to generalize these results for females or nontreatment-seeking populations. Third, impaired cognitive functions that are associated with severe ADHD symptoms or dissociative experiences may interfere with results of self-rating scales and thus make these results less reliable. Finally, to generalize the findings of the present study, further study is needed in wider, mixed gender, nontreatment-seeking population with AUD.

CONCLUSIONS

We may suggest that the effect of ADHD symptoms on the severity of dissociative experiences may be both direct and indirect, with latter being through severe physical abuse. Since our study is not prospective in structure, it is not possible to demonstrate the casual relationship between ADHD, childhood abuse, and dissociative tendency exactly. However, at least these findings demonstrate that the presence of severe IN symptoms is an important factor related with dissociative tendency in AUD population with a history of physical abuse. Thus, when working with AUD patients, clinicians should evaluate ADHD and dissociative symptoms carefully. Furthermore, all types of childhood trauma must be considered in this population and treatment strategies should be planned accordingly.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.