Childhood Trauma and Adult ADHD

While studies have documented higher prevalence of abuse in children with ADHD, no studies have investigated childhood reports of abuse in adults identified with ADHD in adulthood. Forty women with ADHD, 17 males with ADHD, 17 female controls and 40 male controls completed the Childhood Trauma Questionnaire and other measures of psychosocial functioning. Emotional abuse and emotional neglect were significantly more common among men and women with ADHD, compared to male and female controls. Sexual abuse and physical neglect were more commonly reported by females with ADHD. Although abuse during childhood was significantly correlated with depression and anxiety in adulthood, having ADHD was a better predictor of psychosocial functioning in adulthood. Clinicians should be aware that patients with ADHD symptoms may have a high probability of having a history of child abuse. Although there appears to be a strong relationship between ADHD symptomatology and child abuse, the direction of the relationship is not yet apparent. Childhood Trauma and Adult ADHD 3 Historically, Attention-Deficit/Hyperactivity Disorder (ADHD) has been primarily considered a disorder of childhood (American Psychiatric Association, 1994); however, there is now clear evidence that ADHD symptoms do not disappear with the onset of adulthood. Numerous prospective and retrospective studies of children diagnosed with ADHD followed into adulthood have demonstrated that from 50% to 80% of individuals continue to experience significant ADHD symptoms and associated impairments into their adult lives (Weiss & Hechtman, 1993; Wender, 1995). It has been established that approximately 5% of children are known to be affected by this disorder; thus, it is thought that 2% of adults suffer from ADHD, making it an underdiagnosed adult psychiatric disorder (Shekim, Asarnow, Hess, Zaucha, & Wheeler, 1990). Research confirms that in adulthood, individuals diagnosed with ADHD in childhood have ongoing difficulties such as poor academic and job performance, lower socioeconomic status (Satterfield, Hoppe, & Schell, 1982; Weiss & Hechtman, 1993), higher incidence of divorce, job and residence changes, and automobile accidents than people without ADHD (Fargason & Ford, 1994). Despite the advances in recent years in identifying ADHD symptoms and the recognition that the disorder can exist in adults, there are still many adults being diagnosed who were not identified as children (Wender, 1995). Very little research has focused on this group, but some findings have suggested that many of the psychiatric and cognitive features that the adults display are similar to those found in children with ADHD. Consistent findings include high rates of antisocial, major depressive, and anxiety disorders with similar levels of concurrent symptoms seen in children and Childhood Trauma and Adult ADHD 4 adolescents with the disorder (Biederman, Newcorn, & Sprich, 1991; Shekim et al., 1990), low self-esteem, self-loathing, and underachievement (Ratey, Greenberg, Bemporad, & Lindem, 1992). While it is fairly well established that adults identified with ADHD have many psychosocial and psychiatric problems as well as a more negative recall of their childhoods (Rucklidge & Kaplan, 2000), the assumption has been that these associated difficulties are likely directly related to the presence of ADHD. Another possible mechanism leading to psychosocial problems in adulthood may actually be the result of other factors, one being the presence of early childhood abuse. The goal of the present study was to extend previous work on recall of childhood experiences in order to investigate prevalence rates of childhood trauma in a population of adults with ADHD. In addition, the relative impact of ADHD and abuse on psychosocial functioning was evaluated. Sedlack and Broadhurst (1996) reported that physical, sexual and emotional abuse affect 18 out of every 1000 children in the United States. However, incidence rates have often been criticized as being underestimates as they only account for the reported cases. Lifetime prevalence estimates of childhood maltreatment are derived by asking adults about their childhood experiences. For example, MacMillan and colleagues (1997) asked 10,000 Ontario residents 15 years and older about both physical and sexual abuse in childhood. A history of child physical abuse was reported more often by males (31.2%) than females (21.1%), while sexual abuse was more commonly reported by females (12.8%) than males (4.3%). A handful of studies have investigated the relationship between ADHD and childhood abuse, all of which used child populations. There is a high degree of overlap Childhood Trauma and Adult ADHD 5 between the symptoms of ADHD and post-traumatic stress disorder (PTSD), including inattention, restlessness, irritability and impulsivity (Weinstein, Staffelbach, & Biaggio, 2000). For example, inattention, one of the cardinal symptoms of ADHD, may result from re-experiencing trauma, hypervigilance, and/or avoidance of stimuli as a result of trauma (Weinstein et al., 2000). Similarly, hyperarousal could be misconstrued as hyperactivity (Glod & Teicher, 1996). If the trauma has been left unidentified, it is possible that these symptoms could become chronic. It is worth noting that assessments of ADHD do not systematically include an assessment of trauma. Indeed, the DSM-IV does not include PTSD as a differential diagnosis. Further, none of the assessment instruments commonly used to evaluate for the presence/absence of ADHD includes questions of trauma (Weinstein et al., 2000). Research has indicated that a history of abuse does serve as a risk factor for future psychopathology (Fergusson, Horwood, & Lynskey, 1996). The psychological sequelae of childhood abuse are well documented to include depression, anxiety, behavioural problems, sleep and somatic complaints, aggression, PTSD, and ADHD (see Weinstein et al., 2000 for a review). Those studies that have investigated the prevalence of ADHD in a population of abused children have found a high overlap between ADHD and PTSD. Merry and Andrews (1994) found an unexpectedly high rate of ADHD, double that found in the community population, in their sample of sexually abused children 12 months after disclosure of the abuse. McLeer and colleagues determined that 46% of their sample of children with a history of sexual abuse met ADHD criteria (McLeer, Callaghan, Henry, & Wallen, 1994). They also determined that 23% of the sexually abused children met criteria for both ADHD and PTSD, a clustering of symptoms that was not noted in the Childhood Trauma and Adult ADHD 6 psychiatric outpatient comparison group. Glod and Teicher (1996) not only found an ADHD prevalence rate of 21% in their sample of abused children but also that abused children with PTSD show activity levels as measured by an actigraph similar to children with ADHD. Very little research has been done investigating the rate of trauma exposure in an ADHD population. While Ford and colleagues (1999) found that a significant number of their children with ADHD had a history of both victimization (32%) and nonvictimization trauma (53%), ODD, rather than ADHD, was found to be associated with an increased likelihood of exposure to trauma. A 4 year prospective study determined that children identified as ADHD were not at higher risk for a traumatic experience than the comparison group, with 12% of the ADHD group reporting a trauma at the follow up period (Wozniak et al., 1999). ADHD was not found to be a risk factor for trauma in boys. The literature to date indicates that there appears to be a relationship between ADHD, trauma and PTSD in children. What has not been investigated is whether a population of adults identified with ADHD is more likely to report a childhood history of abuse. We expected that in a sample of adults with ADHD there would be a significantly higher prevalence of past reports of abuse than in adults without the disorder. Further, while it has been well documented elsewhere that adults with ADHD have more psychosocial problems as compared with adults without ADHD (Rucklidge & Kaplan, 1997), what has not been investigated is whether abuse and/or presence of ADHD is accounting for more of the problems in adulthood. As such, predictors of psychosocial functioning were also investigated. Childhood Trauma and Adult ADHD 7 Method Subjects: This project combined data from two separate studies of adults with ADHD (Brown, 2003; Rucklidge & Kaplan, 2000). In total, there were 114 participants: 17 men with ADHD, 40 women with ADHD, 17 women without ADHD, and 40 men without ADHD. Both studies were approved by the Conjoint Health Research Ethics Board in the Faculty of Medicine at the University of Calgary. The initial results on perceived abuse in childhood reported by Brown and colleagues (Brown, Crawford, & Kaplan, 2003) prompted the research team to send out the Childhood Trauma Questionnaire (CTQ; Bernstein & Fink, 1998) to all participants in that study, as well as to those who participated in the earlier study by Rucklidge and colleagues (2000), despite the fact that, over that time frame, a number of subjects had moved and were unreachable. The CTQ had been published after Brown et al. had collected data for the study, but given the initial findings, ethics approval was obtained to recontact all subjects in both studies to further explore this realm. For the men and women with ADHD, only adults who believed they had attentional difficulties but were not diagnosed with ADHD in childhood were invited to participate. Both groups without ADHD had at least one child diagnosed with ADHD. Recruitment was carried out via a database of participants who had volunteered for previous studies, through word of mouth, particularly friends of earlier participants, through the local chapter of Children and Adults with Attention Deficit Disorder (CH.A.D.D.), and through advertisements posted in psychiatrists’ and psychologists’ offices. Over half of the subjects came from the database of participants volunteering for Childhood Trauma and Adult ADHD 8 previous studies, and the remaining subjects most frequently had heard of the study either by word of mouth or through CH.A.D.D. Measures Attention-Deficit/Hyperactivity Disorder: The Conners' Adult ADHD Rating Scale Self Report: Short Version (CAARS-S:S; Conners, Erhardt, & Sparrow, 1999) was used to measure ADHD symptomatology for the men with ADHD and also for half of the women with ADHD. The CAARS-S:S is a 26-item scale that assesses the core symptoms of ADHD, as well as related problem areas. Coefficient alphas for the CAARS ranged from .86 to .92, with median test-retest reliabilities of .89 (Conners et al., 1999). For the remainder of the sample, ADHD symptomatology was examined using the Attention Deficit Disorder Checklist (Kaplan & Humphreys, 1995). This 25-item checklist was based on the DSM-IV criteria for ADHD, each scored on a scale from 0 to 3. Probability codes are generated from the total scores obtained, indicating the likelihood that the subjects were affected or unaffected by ADHD symptomatology. Child Abuse: The Childhood Trauma Questionnaire (Bernstein & Fink, 1998) was used as a measure of childhood or adolescent abuse. This 28 item self-report retrospective questionnaire asks the subject to respond on a 5-point Likert scale ranging from “never true” to “very often true”. Emotional, physical neglect and abuse, as well as sexual abuse are measured, while other traumatic events that may occur during childhood such as the death of a parent or a major illness are not assessed. All factors, with the exception of physical neglect, demonstrated good internal consistency and test-retest reliability (Paivio