رابطه بین اختلال نقص توجه و بیش فعالی و خلق و خوی کودک

This study examined empirical and theoretical differences and similarities between attention deficit hyperactivity disorder (ADHD) and child temperament in 32 ADHD children aged 6–11 years, and a comparison group of 23 children with similar sociodemographic characteristics. Children were assessed for ADHD symptoms (hyperactivity, impulsivity, and inattention) and dimensions of child temperament (negative reactivity, task persistence, activity, attentional focusing, impulsivity, and inhibitory control) using standardized parent reports and interviews. Symptoms of ADHD and temperament dimensions were correlated; children in the ADHD group had significantly higher scores on negative reactivity, activity and impulsivity, and lower scores on task persistence, attentional focusing and inhibitory control than normative samples. Results indicate that although the constructs of ADHD and temperament have been regarded as two separate bodies of knowledge, theoretical and empirical overlaps exist. Applied implications are discussed.

ADHD is one of the most common behavioral disorders diagnosed in children and adolescents. Although prevalence varies among different communities and is dependent upon the criteria used for diagnosis, national estimates indicate that 3%–5% of school-age children have been diagnosed with ADHD (National Institutes of Health, 2000). The criteria for a diagnosis of this disorder include impairment within the areas of activity, attention, and impulsivity (American Psychiatric Association, 2000). The same behaviors are regarded differently from a temperament perspective. Temperament theorists view children's temperaments as existing on a continuum that includes a wide range of normal variations (Cloninger, 1987 and Rothbart and Bates, 1998). While children whose temperaments at the extreme end of the continuum are more arduous for parents and teachers to manage, their behavior is still considered normal. Although the terminology used to diagnose ADHD is also used in the temperament literature (activity, impulsivity, inattention and low task persistence), few empirical investigations have examined these domains simultaneously. Instead, research in the fields of child temperament and child psychopathology, as related to attention deficit hyperactivity disorder, have been regarded as two separate bodies of knowledge. The purpose of this study was to examine the theoretical differences and similarities of child temperament and ADHD. 1.1. Attention deficit hyperactivity disorder (ADHD) A diagnosis of ADHD in the US is based on the criteria cited in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR; American Psychiatric Association, 2000). The subtypes are ADHD inattentive, ADHD hyperactive–impulsive, and ADHD combined. Inattention includes failing to pay close attention to details or making careless mistakes, having difficulty sustaining attention, not listening, not following through, having difficulty organizing, having low task persistence, losing things, being easily distracted, and being forgetful. Hyperactivity includes fidgeting, being out of seat, running or climbing excessively, being unable to play quietly, constantly moving, and talking excessively; impulsivity includes calling out answers, having difficulty waiting in turn, and interrupting. The presence of six or more symptoms in each of these two groups is considered a clinical diagnosis. Symptoms must be present before age seven years, impairment must be seen in two or more settings, and evidence of impairment in both social and academic functioning must be documented ( American Psychiatric Association, 2000). ADHD symptoms predict a decrease in children's functioning in all areas of their environment, including learning problems and difficulty in relationships with family members, teachers, and peers ( Barkley, 1998). Such problems often are correlated with low self-esteem and low self-efficacy which are further predictive of poor school outcomes ( Dulcan et al., 1997). ADHD is a common childhood disorder that results in major public health costs. Public school expenditures for children diagnosed with ADHD have averaged between $3.5–4 billion annually (National Institutes of Health, 2000). Society generally shares in this burden because these children consume a disproportionate share of resources in the health care system, schools, social services, and the criminal justice system. Manuzza, Klein, Bessler, Malloy, and LaPaluda (1998) found that children with ADHD were at a significantly higher risk for antisocial disorders in adulthood. Likewise, children with ADHD are also at higher risk for substance use and dependence in adolescence and adulthood (Flory and Lynam, 2003, Manuzza et al., 1998 and Molina et al., 1999). A national survey revealed that students with ADHD were more likely to receive special services than their non-ADHD special education peers (Schnoes, Reid, Wagner, & Marder, 2006). In addition, families of children with ADHD can experience a financial burden when their health insurance does not cover treatment. The identification of children with ADHD remains challenging. However, multiple tools are available to assist in the diagnosis of ADHD. Parent, teacher and self-report instruments as well as structured interviews exist. An accurate assessment in different environments and from differing perspectives is essential for an accurate diagnosis and for proper treatment. It must be kept in mind that parents and teachers do not always agree. Low correlations between their reports can be partially accounted for by memory of the event, subjectivity, and individual interpretation of behaviors. Once a child is diagnosed, parents can be confused about the treatment choices because recommendations vary considerably. Treatments for the disorder include medication, behavioral interventions, or a combination of the two (multimodal). Between 76% and 99% of children diagnosed with ADHD are medicated with stimulants or with the nonstimulant atomoxetine. The most commonly used stimulants are methylphenidate (in both oral and transdermal routes), a mixture of amphetamines called Adderall, and dextroamphetamine (Dexedrine). The functional and interpersonal behavior of many children with ADHD is impaired in multiple settings, and medications can dramatically decrease problem behaviors in many of these children. In general, their activity level is reduced, attention is improved and impulsivity may be lessened. In contrast to their peers without a diagnosis of ADHD, however, troublesome behaviors still remain high (National Institutes of Health, 2000). Behavioral management techniques designed to decrease the frequency and severity of such troublesome behaviors have been taught to both parents and/or teachers. These techniques have been tested in controlled classrooms, psychoeducational groups and specialized summer camps. Such techniques are derived from behavior modification, social skills training, parent and teacher training and support groups (Pelham & Hoza, 1996). For treatments to be most effective, they need to be implemented in multiple settings, including the home, school and community (Pelham et al., 2000). Gaining consistency among multiple providers can be difficult. Although medication has been shown to be the most effective single modality in reducing symptoms and behaviors associated with ADHD, children who receive multimodal treatment can achieve equal efficacy with lower doses of medication (MTAGroup, 1999). Multimodal treatment involves both medication as well as behavioral interventions, which include behavior modification and social skills training in multiple settings such as the home, school and social environments. Each treatment modality has its advantages and limitations. Adherence to treatments by parents and children is difficult. Behavioral interventions are time-consuming and require considerable efforts on the part of both parents and teachers in order to see improved behaviors in the child. 1.2. Temperament Temperament is defined as a behavioral style that individuals consistently exhibit in reaction to their environments (Buss and Plomin, 1984, Chess and Thomas, 1984 and Rothbart and Bates, 1998). It encompasses the affective, activational, and attentional sectors within personality and acts as a screen through which children view and interact with their environment. Temperament is evident early in life, relatively stable across time and situations, biologically driven, and genetically linked. Two complimentary perspectives of child temperament are particularly relevant when exploring the similarities and differences of the construct with ADHD. From a behavioral perspective, McClowry (1998) defined school-age temperament as inborn dispositions that influence reactions to situations, especially those involving change or stress. She identified four dimensions of school-age temperament (McClowry, 1995): Negative reactivity (intensity and frequency with which the child expresses negative affect), task persistence (persistence or attention span), activity (motor behavior), and approach/withdrawal (initial response to new situations). These four domains, or close equivalents, are supported by other studies of children (Ahadi and Rothbart, 1994, Presley and Martin, 1994 and Sanson et al., 1994). Based on combinations of dimensions, McClowry (2002) also identified temperament typologies. Fourteen percent of children in her study of 883 participants had a “high maintenance” temperament profile. High maintenance children were high in activity and in negative reactivity and low in task persistence. This typology mirrors the symptoms of ADHD. This profile was developed by second order principal factor analysis with varimax rotation of the temperament dimensions from the School-Age Temperament Inventory. Dimension scores were divided by thirds to determine if they were high, medium or low. The dimensions of this profile are illustrated in a scoring sheet for temperament profiles presented in Appendix A. Emphasizing psycho-neurobiological components, Rothbart and her colleagues have studied variability in arousability and distress and its relationship to overstimulation, activity, and attention (e.g., Rothbart, Ellis, & Posner, 2004). Rothbart and her colleagues purport that attention has both reactive and self-regulative aspects. The development of attentional focusing is linked to a child's ability to sustain attention over an extended period. With age and experience, children develop increased capacity for effortful control (Rothbart & Bates, 1998). Although Rothbart (Derryberry and Rothbart, 2001 and Rothbart and Derryberry, 1981) and McClowry (2003) emphasize different facets of temperament in their definitions and measurement, both perspectives can be subsumed under the general heading of self-regulation. Self-regulation is the ability to accomplish goals by self-moderating emotional, attentional, and behavioral responses to events (Rothbart et al., 2004). Children who are low in self-regulation demonstrate difficulties in paying attention at school, organizing tasks, making and retaining friends, moderating emotional displays, and controlling impulsive behaviors (Clark et al., 2002, Miller et al., 2004, Murphy et al., 2004 and Raver et al., 1999). These same behaviors and developmental outcomes are regarded as symptoms of ADHD but can also be viewed as the effects of behavior at the extreme end of normal child temperament. 1.3. The relationship between ADHD and temperament Despite the theoretical overlap between the constructs of ADHD and of temperament, only two studies have examined their empirical relationship (Bussing et al., 2003 and McIntosh and Cole-Love, 1996). McIntosh and Cole-Love (1996) found that parents and teachers rated the temperaments of ADHD-classified and “normal” children differently. These researchers studied 70 male children, 35 with ADHD and 35 without the disorder, ranging from 5 to 8 years old. Participants, predominantly Anglo-American middle-class families in the Midwest US, were rated by both parents and teachers on the Temperament Assessment Battery for Children. McIntosh and Cole-Love concluded that children diagnosed with ADHD exhibited temperaments high in activity, high in distractibility, and low in persistence. Those without a diagnosis of ADHD were rated by their parents and teachers to be lower in activity, distractibility and higher in task persistence. Bussing et al. (2003) studied the temperaments of 200 eight- to ten-year old male and female (n = 52.5%) children who screened positive on the Diagnostic Interview Schedule for Children (DISC) for the ADHD-combined subtype based on parent reports. The children who screened positive for ADHD-combined subtype also self-reported low in task orientation and high in activity as measured on the Dimensions of Temperament Survey (DOTS; Lerner, Palermo, Spiro, & Nesselroade, 1982). Children with the combined subtype ADHD scored significantly higher on the activity level-general dimension (p < .05) and significantly lower on task orientation (p < .01) than did children in the non-ADHD group. Lemery, Essex, and Smider's (2002), longitudinal study of 451 children examined item overlap between the dimensions of temperament on the Child Behavior Questionnaire and Preschool Behavior Questionnaire and the symptoms of ADHD on the MacArthur Health and Behavior Questionnaire (HBQ; Ablow et al., 1999). To assess ADHD, the researchers used the behavior problem composite for Attention Deficit (inattention and impulsivity subscales). When both empirical and conceptual confounded items were removed, moderate associations (.44 to .59) remained between the temperament dimensions of activity level, attentional focusing and inhibitory control and ADHD symptoms of inattention and impulsivity. 1.4. The present study The results from Bussing et al. (2003) and McIntosh and Cole-Love (1996) provide some empirical support for a relationship between the constructs of ADHD and child temperament. Questions remain regarding the distinctions between temperament and a diagnosis of ADHD, the strengths of the associations, and the implications for prevention and treatment. In the present study, the following research questions were asked: (1) What are the associations between the temperament dimensions of negative reactivity, task persistence, activity, attentional control, impulsivity and inhibitory control and the ADHD symptoms of hyperactivity, impulsivity, and inattention in school-age children? (2) Is the temperament of school-age children who screen positively for ADHD significantly different from those who do not? (3) Are school-age children who screen positively for ADHD disproportionately overrepresented on the high maintenance temperament profile?