The term "aggression" may be applied to aggressive actions (behavior); to "states of mind" such as rage, anger, or hostility (subjective feelings); and to aggressive drives, inclinations, thoughts, and intentions (motivations).1 The imprecision and scope of the term often leads to confusion when applied to the assessment or characterization of children with behavioral disorders. This article offers a characterization of childhood aggressive behavior, theories of its etiology and evaluation, and appropriate therapeutic strategies.
CHARACTERIZATION OF CHILDHOOD AGGRESSIVE BEHAVIOR
Aggressive behaviors are ubiquitous during childhood. As children move from infancy to childhood they increasingly express frustration through acts of hostility, quarrelling, and combativeness. Angry outbursts in the younger child, peaking at 2 years of age, may include kicking, stamping, jumping up and down, throwing oneself on the floor, holding ones breath, pulling, struggling, pouting, frowning, throwing objects, grabbing, biting, striking, crying, and screaming.2 Between the ages of 2 and 5, these acts become less random and are often aimed at something or someone. Such outbursts usually last less than 5 minutes and are frequently caused by denial of attention, conflicts over going to bed, taking baths, or toilet training, or in response to punishment or prohibitions. As demonstrated in numerous studies, these behaviors decrease with time, with boys exceeding girls at every age in both duration and severity of expressed aggressive behavior.
Despite an overall reduction with aging, some children continue to demonstrate aggressive behavior. Behaviors found in children aged 4 to 16 with aggressive syndrome include: frequent arguing, cruelty, bullying, or meanness to others; demands for attention; disobethence at home; frequent jealousy; considerable fighting; physical attacks on others; screaming; stubbornness, sullenness or irritability; sudden changes in mood or feelings; frequent teasing; temper tantrums or hot temper; threatening others; and unusual loudness or boisterousness.3 When populations of normal children 4 to 16 years old were compared with a group of children referred for mental health services, aggressive behaviors were higher in both girls and boys referred for mental health services than in normal children. Although aggressive behaviors were higher in younger children, they remained higher in the referral population than among normal children at all ages.4
Numerous studies have documented that children with extreme aggressive behavior compared with normal children demonstrate an increase in dysfunction during adolescence and adulthood. 5-7 These prospective longitudinal studies clearly document that the long term prognosis in approximately 50% of this population is poor. Impairments in these adults include psychiatric disorders, criminal behavior, physical disabilities, and impairments in social adjustment.
THEORIES OF ETIOLOGY
There is no unified model or theory explaining the etiology of childhood aggressive behavior, which suggests the term does not describe a single entity but rather multiple phenomena.
One of the first hypotheses postulates that aggression is a response to frustration. Frustration is defined as the blocking of an ongoing goal-directed activity; aggression is the resulting behavior aimed at inflicting injury.8 This model applies to numerous instances of manifest aggression not only where children experience the frustrations of developing age-appropriate impulse control but also in circumstances such as low economic status, minority group disadvantage, or a chaotic home, where frustration may occur due to the inequities of the environmental situation. It can also apply to populations with poor frustration tolerance and resulting low impulse control, as in children with neurological deficits, attention deficit disorders, mental retardation, autism, learning disabilities, and affective and thought disorders.
Social Learning Theory
There are two components of influence to consider in the assessment of aggression: causative or instigative factors and sustaining factors. Aggressive behaviors are assumed to be acquired either by direct experience or by observing the behavior of other people.
Parents, either directly through parenting techniques or indirectly by acting as role models, are crucial in the formation of aggressive behaviors. Parental interventions that would lead to a child's failure to substitute adaptive mature behaviors for primitive aggressive behavior include parental neglect in conditioning prosocial skills, such as the use of language to express emotions; positive reinforcement of coercive and aggressive behavior; inconsistent use of punishment; and weak conditional punishment.9 Parents of boys with aggressive behavior have been shown to encourage and model aggression in their attitudes and use of physical punishment and deprivation. Two major causes of the aggression were fathers' hostility toward their sons and mothers' rejection and hostility toward their sons' dependency.10 Children learn many behaviors through modeling, ie, by observation and replication. When compared with the parents of normal children, parents of children with aggressive behaviors tend not only to have more aggressive behavior but also other deviant behavior as well, including alcoholism, criminality, sexual promiscuity, and psychoses.
Several environmental factors may act both as models for the child to imitate and as sources of reinforcement. The family community and its acceptance of aggression, the relationship with siblings, and the acceptance of aggression by other family members are just a few environmental factors to be considered. An important source of aggressive models that are not often recognized or given enough attention is television violence. With the increase of video cassette recorders in the home, there is a growing opportunity for children to be exposed to increasingly violent material. Numerous studies have documented the deleterious effects of children viewing this material.11
Norepinephrine, serotonin, and gamma-aminobutyric acid (GABA) have been implicated in the expression of aggression. Animal and clinical studies utilizing studies of blood and cerebrospinal fluid levels of principle neurotransmitters, their metabolites, and their respective receptor populations strongly suggest that the noradrenergic system facilitates aggressive behavior. By contrast, serotonergic and GABAergic systems inhibit aggressive behavior.12 Three broad conclusions concerning the role of neurotransmitters in the expression of aggression are that no single transmitter serves as the unique substance that mediates aggression; the behavioral action of the various neurotransmitters is not uniquely limited to the expression of aggression; and the role of a particular neurotransmitter appears to depend on the type of aggression being studied (affective versus predatory).13-16
In addition to the postulated roles of neurotransmitters in the expression of aggressive behavior, other biological explanations have been proposed, including: 1) maleness, either as an expression of genetic or hormonal influences; 2) inherited patterns of antisocial behavior; 3) sex chromosomal defects (eg, XYY, XXY); 4) neuroanatomical substrates in the amygdala and other limbic structures; and 5) epilepsy and related disorders.17
EVALUATION OF CHILDHOOD AGGRESSIVE BEHAVIORS
The frequency, duration, and severity of the aggressive episodes must be determined. Usually, children show aggressive behavior in predictable ways, at certain times, in certain settings, toward certain objects or individuals, or in response to certain stimuli. The age of the child must be taken into consideration. Obviously, an aggressive act by a 2-year-old will have different implications than in a 10-year-old. One system for characterizing aggression uses the Overt Aggression Scale.18 This scale has the advantages of measuring four types of aggression, of being operationalized, and of having a built-in severity rating for each type of aggression, a measure of the duration of the episodes, and the intervention necessary to stop the episode. The disadvantages are it is not sensitive to developmental aspects of the display of aggressive behavior and it does not facilitate the assessment of the aggressive behavior.
Has the aggressive behavior been present since an early age? Does the behavior have a recent onset? Was the onset precipitous? If precipitous and without a clear precipitating incident, evaluate for a closed head injury, physical or sexual abuse, or other recent traumatic events.
Does the behavior appear to occur in all settings, ie, home, school, in the homes of peers and other family members, or in public settings other than school such as church, the grocery, or the mall? Can the aggressive behavior occur with anyone or is it with the parents or primary caregivers only? Does it happen with both parents?
Possibility of Psychiatric Disorder
Aggressive behavior is often a symptom of an unrecognized psychiatric disorder including depressive disorders (major depressive disorder or dysthymia), psychoses (childhood schizophrenia, autism, or pervasive development disorder), speech and language disorders, or organic brain syndrome. The American Psychiatric Association's Diagnostic and Statistical Manual, ed 3, Revised (DSM-III-R) can assist in the formulation of cases and in determining the presence of psychopathology.19
An important clinical association that can occur is depression and aggression. Early theories suggested that depression could not be experienced directly by a child but would be expressed as "depressive equivalents,"20 while others speculated that depression was "masked" and not manifestly evident in children.21 These observations supported the relationship between aggression and depression but implied that depression among children could not be identified directly. Numerous studies have not only proven that depression can be identified in children, but also have supported the association of depression and aggressive behaviors.22-24 Any child who presents with age-inappropriate aggressive behaviors should be assessed for depression.
If the child has been identified as having a psychiatric disorder, review the previous treatments. What medications have been tried? Were the medications given in doses that were within a therapeutic range? How were the medications monitored (by blood levels)? Did the medications worsen the aggressive behavior?
Are there suggestions that the child is learning disabled or mentally retarded? A review of school records can be very helpful, as well as psychological testing performed by the school.
How do the parents set limits? Are the parents punitive? Do the parents use physical punishment? Are the parents consistent? Do the parents set limits together or is one parent the sole disciplinarian?
Is there a family history of child abuse (either sexual or physical), depression or suicide, alcoholism, criminal conduct, or childhood aggressive behaviors? Are the parents currently experiencing any of these difficulties? How do the parents deal with aggression with the child and their peers? Are the parents moody? Are they emotional and labile? Is there spouse abuse, alcoholism, or drug abuse in the home?
In what type of neighborhood does the child live? Is there environmental support for aggressive behavior, ie, gangs or other youth with reputations for aggressive behavior? Is the child frequently exposed to violent television programming? Is there any effort on the part of the parents to monitor the television viewing habits of the child?
THERAPEUTIC STRATEGIES FOR AGGRESSIVE BEHAVIOR
The treatment of aggressive behavior in a child requires a multidimensional approach involving interventions with the parents, the child, and in some cases the school. Within this context psychopharmacological agents may be used to decrease the severity of the aggression and the frequency of the episodes. A child should never be given medications for aggressive behavior unless it is part of a therapeutic program. Depending on the child, attention must be given to a broad array of variables in determining the best strategy.
Exposure to aggressive models must be reduced. This may be particularly difficult if the primary models are the parents. However, this may also involve decreasing exposure to aggression in the community and in violent television programs. Models should be provided for non-aggressive behavior, such as coaches, teachers, the parents of other families, or members of the extended family. Reduce aversive stimuli. Attempts should be made to help the parents use empathie and direct techniques of managing the child's aggressive behavior rather than physically or verbally abusive methods. Increase social skills through a program of instruction, modeling, role playing, and feedback.1,7
Parent Management Training
Parents are trained to interact differently with their child with the assumption that the aggressive behavior is the result of a faulty parent-child relationship. Techniques may include establishing rules for the child to follow, delivering mild forms of punishment (such as time out) to suppress aggressive behavior, providing positive reinforcement, and negotiating compromises.7
A number of pharmacotherapeutic agents have been reported to decrease the frequency and severity of aggressive behavior.25-27 These include lithium carbonate, propranolol, carbamazepine, and haloperidol. Lithium carbonate has been shown to be as effective as haloperidol and to have far fewer side-effects in children. In particular, lithium has been shown to be effective when the aggression is accompanied by explosive episodes. Antipsychotics or neuroleptics, such as haloperidol and thioridazine, can be given either on a short term basis to manage an acute episode or on a long term basis after other medications such as lithium, propranolol, or carbamazepine have been tried.
Methylphenidate, the most frequently used psychopharmacological agent in child behavioral management, has not been shown to effectively decrease aggression. In tact, evidence suggests that it worsens aggression in children. Therefore, when assessing a child for an attention deficit disorder it is imperative that the child be assessed for the presence of aggressive behavior as well.
Several general principles need to be followed when administering psychopharmacological agents: treat the primary illness; use the most benign interventions when beginning treatment; have some quantifiable means of assessing efficacy; and institute drug trials systematically. 27
Aggressive behavior can be found as a normal developmental variant at all ages in both sexes. This and the lack of clear guidelines in determining the point at which normal aggression becomes pathological makes the clinical management of childhood aggressive behaviors very difficult. When confronted with this clinical situation, a multidimensional assessment is important before starting intervention. Medications are most helpful when the aggression is pervasive or associated with alterations in mood, thoughts, and anxiety. If all else fails, one should not hesitate to contact a mental health professional trained to assist in the evaluation and treatment of these children.
1. Herbert M: Conduct Disorders of Childhood and Adolescence: A Social Learning Perspective, ed 2. New York. John Wiley and Sons. 1987.
2. Goodenough FL: Anger in Young Children. Institute Child Welfare Monograph Series. No. 9. Minneapolis, University of Minnesota Press. 1931.
3. Achenbach TM: Developmental Psychopathology, ed 2. New York, lohn Wiley and Sons. 1987.
4. Achenbach TM, Edelbrock CS: Behavioral problems and competencies reported by parents of normal and disturbed children aged 4 through 16. Monographs of the Society for Research in Child Development. 46. Serial No. 188, 1981.
5. Robins LN: Deviant Children Grown Up. Baltimore, Williams & Wilkins. 1966.
6. Lefkowitz MM. Eron LD. Walder LO, et al: Crowing Up to be Violent: A Longitudinal Study of Aggression. Oxford. Persamim Press, 1977.
7. Kazdin AE: Conduct Disorders in Childhood and Adolescence. Beverly Hills, Calif, Sage Publications. Inc. 1987.
8. Dollard J. Dobb LW, Miller NE. et al: Frustration and Aggression. New Haven. Conn, Yale University Press. 1939.
9. Patterson GR. Reid JB, Jones JJ, et al: A Social Learning Approach to Family Interventions: I. Families with Aggressive Children. Eugene. Ore, Castalix Publishing Co, 1975.
10. Bandura A: Aggression: A Social Learning Analysis. Englewood Cliffs, NJ. PrenticeHall. 1973.
11. Melville-Thomas G: Television violence and children, in Barlow G, Hill A (eds): Video Violence and Children. Great Britain. Hodder and Stoughton, 1985.
12. Reis DJ, Central neurotransmitters in aggressive behavior, in Fields WS, Sweet WH (eds): Neural Basis of Violence and Aggression. Sr Louis, WH Gree, 1975.
13. Brown G. Ebert M. Goyer P, et ai: Aggression, suicide, and serotonin: Relationships to CSF amine metabolites. Am J Psychiatry 1982: 139:741-746.
14. Eichelman B, Elliot GR. Bart has JD: Biochemical, pharmacological and genetic aspects of aggression, m Hamburg DA, Trudeau MB (eds): Behavioral Aspects of Aggression. New York. Alan R. Liss. Inc. 1981.
15. Lidberg L, Tuck JR. Asberg M. er al: Homicide, suicide and CSF 5-HIAA. Acta Psychiatr Scandinavia 1985: 71:230-236.
16. Traskman L. Asberg M, Bertilsson L. et al: Monoamine metabolites in CSF and suicidal behavior. Arch Gen Psychiatry 1981: 38:631-636.
17. A lessi NE, Rome LH: Juvenile delinquency: Conceptual and forensic implications of depression, in Feldman RA. Stiffman AR (eds): Advances m Adolescent Mental Health III. Depression and Suicide. JA1 Press, Inc. In Press.
18. Yudofsky SC, Silver JM, Jackson W. el al: The overt aggression scale for the objective rating of verbal and physical aggression. Am J Psychiatry 1986: 143:35-39.
19. The Diagnostic and Statistical Manual of Psychiatric Diagnoses, ed 3, Revised. The American Psychiatric Association, 1987.
20. Toolen J: Depression in children and adolescents. Am J Orthopsychiatry 1962; 32:404-414.
21. Glasser K: Masked depression in children and adolescents. Am I Psychother 1967; 21:565-574.
22. Puig-Antich J : Major depression and conduct disorder in prepubetty. J Am Acad Child Psychiatry 1982: 21:118-128.
23. Alessi N. McManus M, Grapentine L, et al : The characterization of affective disorders in serious juvenile offenders. J Affect Dis 1984: 1:9-17.
24. Alessi N. McManus M, Brickman A. et al: Suicidal behavior in serious juvenile offenders. Am J Psychiatry 1984; 141:286-287.
25. Campbell M. Perry R. Green W: Use of lithium in children and adolescents. Psychiatry Annals 1984; 25:96-106.
26. Campbell M, Cohen IL. Small AM: Drugs in aggressive behavior. J Am Acad Child Psychiatry 1982: 21:107-117.
27. Eichelman B: Toward a rational pharmacotherapy for aggressive and violent behavior. Hosp Community Psychiatry 1988; 39:31-59.