You are in: eMedicine Specialties > Pediatrics: Developmental and Behavioral > MEDICAL TOPICS Childhood Habit Behaviors and Stereotypic Movement DisorderArticle Last Updated: May 3, 2006AUTHOR AND EDITOR INFORMATIONAuthor: Cynthia R Ellis, MD, Director of Developmental Medicine, Associate Professor, Department of Pediatrics and Psychiatry, Munroe Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center Cynthia R Ellis is a member of the following medical societies: Nebraska Medical Association Coauthor(s): Connie Jo Schnoes, PhD, Assistant Research Professor, Department of Special Education & Communication Disorders, University of Nebraska-Lincoln; Holly Jean Roberts, MS, PhD, Post Doctoral Fellow, Department of Developmental Pediatrics, Munroe-Meyer Institute, University of Nebraska Medical Center Editors: Chet Johnson, MD, Medical Director, Child Development Unit, Department of Pediatrics, Professor, University of Kansas Medical Center; Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine.com, Inc; Carrie Sylvester, MD, MPH, Director of Education in Child and Adolescent Psychiatry, Professor, Departments of Psychiatry and Pediatrics, Northwestern University Medical School; Caroly Pataki, MD, Professor of Clinical Psychiatry, Department of Psychiatry and Biobehavioral Sciences, Division Chair of Child and Adolescent Psychiatry, Director of Training, Child and Adolescent Psychiatry Residency Program, University of Southern California Keck School of Medicine Author and Editor Disclosure Synonyms and related keywords: childhood habit behaviors, stereotypic movement disorder, habits, teeth grinding, bruxism, hair pulling, thumb sucking, breath holding, breath-holding spells, stereotypies, nose picking, rocking, nail biting, nailbiting, head banging, headbanging, habitlike behavior INTRODUCTIONBackgroundChildhood habits appear in many different forms. Many people engage in some degree of habitlike behavior in their lifetime. For example, habits can range from seemingly benign behaviors, such as nail biting or foot tapping, to more noticeable physically damaging behaviors, such as teeth grinding (bruxism) and hair pulling. Habit disorders, now subsumed under the diagnostic term stereotypic movement disorder, consist of repetitive, seemingly driven, and nonfunctional motor behaviors that interfere with normal activities or that result in bodily injury. Fortunately, many childhood habits are benign, they are considered a normal part of development, they do not meet the criteria for a disorder, and they typically remit untreated. The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), formerly used the term stereotypy/habit disorder and now uses the term stereotypic movement disorder to designate repetitive habit behaviors that cause impairment to the child. This review focuses on a number of common childhood behaviors, including thumb sucking, nail biting, nose picking, breath holding, bruxism, head banging, and rocking and/or rhythmic movements. In mild forms, some of these behaviors do not interfere with normal daily activities and, therefore, do not constitute psychiatric disorders. However, mild forms of these behaviors can progress to cause functional impairment or physical and/or psychological sequelae or stigmatization. When functional impairment is substantial, the diagnosis of stereotypic movement disorder should be considered. The differential diagnosis of stereotypic movement disorder requires the clinician to rule out a number of other psychiatric conditions in which repetitive behaviors are core features. Examples include obsessive-compulsive disorder, trichotillomania, vocal and motor tics, and Tourette disorder. When these disorders best account for symptoms, stereotypic movement disorder is not diagnosed. Some childhood habits remain unnoticed and can persist untreated, even when they interfere with the child's optimal functioning. Childhood habits can result in negative social interactions and avoidance by peers and family members. Some repetitive behaviors can cause damage. For example, teeth grinding (bruxism) can result in tooth damage. Occasional hair pulling can result in hair loss or evolve into the more severe disorder, trichotillomania. However, for most children who are otherwise developing normally, few habits result in permanent physical damage to the child. In some cases, treating a childhood habit before clearcut dysfunction arises may prevent serious psychopathology and social dysfunction. Much of what is known about childhood habits derives from the literature about common habit behaviors in adults. PathophysiologyThe pathophysiology of specific habits varies greatly with respect to the topography and frequency of the particular habit behavior. Thumb sucking: Thumb sucking is an oral habit that involves mouthing of the thumb. Other fingers or the hand may also be involved. Nail biting: Nail biting consists of biting on or chewing the nails of the hand. Nose picking: Nose picking is the insertion of a finger into a nostril and may involve the removal of nasal discharge (ie, snot, "boogers"). Older children and adults are most likely to pick their nose in private, whereas young children may commonly do this in public view. Bruxism: Bruxism is the forcible gnashing, grinding, clicking, or clenching of teeth. Nocturnal bruxism occurs during sleep, and the child is usually unaware of the problem. Episodes are typically brief, lasting 8-9 seconds, with audible grinding noises. Diurnal (daytime) bruxism is primarily associated with clenching of the teeth and generally does not produce audible noises. Diurnal bruxism is related to other oral habits, such as nail biting or lip chewing. Breath-holding spells: A breath-holding spell is a paroxysmal event in which a child stops breathing at end-expiration after crying, typically because of pain or anger. The crying may be brief or prolonged. Breath-holding spells are classified as simple, cyanotic, or pallid. A simple breath-holding spell results when the child becomes apneic (cyanotic or pale) but then takes a deep breath. Spells with loss of consciousness and muscle tone are classified by the child's color during the event. Cyanotic spells typically have an emotional precipitant (eg, anger, frustration), and with breath holding, the child progresses from cyanotic to apneic. The child may then become limp and lose consciousness. The spell typically lasts less than 1 minute. If a seizure occurs, the results from an electroencephalograph (EEG) obtained during rest or sleep are normal. Pallid spells are generally observed in response to pain, and the child quickly becomes apneic and pale. An enhanced vagal response has been postulated to be a precursor tobradycardia or asystole. Seizures rarely result. Head banging: Head banging is the rhythmic hitting of the head (usually the frontal or parietal region) against a solid surface. In children who are developmentally normal, it usually lasts less than 15 minutes but can last hours. A high frequency of up to 60-80 hits per minute is common. It can be associated with temper tantrums, tension, or stress. Head banging can also develop as a sleep ritual if the head banging occurs as the child falls asleep. Body rocking or rhythmic movements: Body rocking usually involves a forward and backward rhythmic swaying of the trunk at the hips, generally from a sitting or quadruped position. The intensity may be gentle, or it may be forceful enough to move the child's crib or bed. This behavior typically occurs when children are alone in their cribs or beds. Most episodes last less than 15 minutes but may persist up to 30 minutes. Rhythmic or stereotypic behaviors include repetitive nonfunctional motor movements, such as hand flapping or shaking, self-biting, or hitting one's own body. FrequencyUnited StatesAccurate prevalence rates of childhood habits are extremely difficult to estimate because of the various classes of habits and the differing topographies of a child's presenting habit. The prevalence rates of habit disorders are at best unclear, and some remain unknown among children. Future studies will hopefully reveal a more accurate picture of the number of children with the various childhood habit disorders. Estimates from the literature for various types of common habit disorders appear below. Thumb sucking: This is common in infancy and in as many as 25-50% of 2-year-old children. However, it is observed in only 15-20% of 5- to 6-year-old children. Nail biting: This is mainly observed from preschool age to adolescence; the prevalence is as high as 45%-60%. Nose picking: Few studies have been performed. However, in 1 survey, as many as 91% of adults reported nose picking. Breath-holding spells: These are common in up to 4-5% of children younger than 8 years. Bruxism: This is observed in 5-30% of children. Head banging: This can occur in 3-19% of developmentally normal children younger than 3 years. It is more frequently observed in children with autism or developmental delay and in those living in institutional environments. Body rocking and rhythmic movements: These occur in most infants aged 6-12 months. The behavior is most often observed in children with developmental disabilities or sensory impairments; however, it persists beyond age 2 years in 3% of children with normal development. The age of onset and resolution of habit behaviors may be delayed in children with developmental disabilities. Stereotypies are observed in 40-60% of individuals who are institutionalized and have profound mental retardation, 8-10% of individuals who live in the community and have moderate mental retardation, and up to 20% of individuals who live in the community and have mental retardation and autism. Self-injury is less common; it is observed in 10-20% of individuals who are institutionalized and have mental retardation, 1-3% of individuals who live in the community and have moderate mental retardation, and up to 5% of individuals who live in the community and have mental retardation and autism. Mortality/MorbidityBecause childhood habits take various forms, a wide range of mortality and morbidity profiles exist. Mortality is extremely rare.
SexJust as the overall prevalence rates of childhood habits are unknown, data on sex-based differences in prevalence are limited at best. In cases of self-injurious behavior, head banging is believed to occur 3 times more frequently in male individuals than in female individuals. Self-biting may be more prevalent in female individuals than in male individuals.
AgeThe age at which specific habits originate, peak, and remit is related to the individual habit behavior.
CLINICALHistoryThe history consists of reports of observed specific behaviors associated with the individual habit. Intensity, severity, and duration may be variable. Habit behaviors may be present for a long time before consultation is sought. Complaints at the time of presentation for evaluation and/or treatment may be either physical or psychological sequelae of the habit (see Pathophysiology). PhysicalMost childhood habits are benign and have no specific observable physical signs. However, when physical signs are present, they are typically nonpathologic and often previously unnoticed. In severe cases, physical evidence of a habit may be related to an associated injury or physical sequelae of the specific behavior the child engages in.
CausesThe origins of most habit disorders are not well established or understood. Although the pathophysiology of habit disorders varies greatly with respect to the topography and frequency of the particular habit behavior, associated biological and/or environmental etiologic factors may exist. Some habit behaviors emerge from normal repetitive behaviors in infancy (eg, hand and thumb sucking) and are believed to represent intrinsic movement patterns generated by the developing nervous system. Certain behaviors, such as nose picking, which may initially arise as a response to dry nasal membranes and nasal irritation or itching, can later develop into a cycle that is difficult to break. Some behaviors may start spontaneously and then be inadvertently reinforced or maintained by other factors, such as attention. Behaviors that produce arousal or modulate self-stimulation may also be influenced by the level of environmental stimulation; for example, some behaviors may be viewed as entertainment for a bored child or as a means of coping with overstimulation. Repetitive or habitual behaviors may be associated with an underlying condition, such as a sensory impairment or developmental disorder, unrecognized medical or neurologic condition, the side effect of a medication, or a psychiatric disorder. Certain genetic syndromes are associated with repetitive behaviors (eg, skin picking in Prader-Willi syndrome, hand flapping and wringing in Rett syndrome, hand flapping in fragile X syndrome). Possible etiologies or explanations of specific habit disorders are as follows:
DIFFERENTIALSAnxiety Disorder: Obsessive-Compulsive Disorder Anxiety Disorder: Trichotillomania Pervasive Developmental Disorder Pervasive Developmental Disorder: Asperger Syndrome Pervasive Developmental Disorder: Autism Pervasive Developmental Disorder: Childhood Disintegration Disorder Pervasive Developmental Disorder: Rett Syndrome Schizophrenia and Other Psychoses Status Epilepticus
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| Drug Name | Fluoxetine (Prozac) |
|---|---|
| Description | Selectively inhibits presynaptic 5HT reuptake with minimal or no effect in reuptake of norepinephrine or dopamine. Approved for obsessive-compulsive disorder in children >8 y. |
| Adult Dose | 20-80 mg/d PO |
| Pediatric Dose | <8 years: Not established 8-18 years: 10 mg PO qd initially; may uptitrate; not to exceed 20-30 mg/d for lighter children and 60 mg/d for heavier children or adolescents |
| Contraindications | Documented hypersensitivity; monoamine oxidase inhibitor (MAOI) use within 2 wk; coadministration with thioridazine |
| Interactions | Increases toxicity of diazepam and trazodone by decreasing clearance; interacts with many drugs due to inhibition of cytochrome P450 (CYP) 2C9, CYP2C19, CYP2D6, CYP3A4; also increases toxicity of MAOIs and highly protein-bound drugs; 5HT syndrome (ie, myoclonus, rigidity, confusion, nausea, hyperthermia, autonomic instability, coma, eventual death) occurs with simultaneous use of other serotonergic agents (eg, anorectic agents, tramadol, buspirone, trazodone, clomipramine, nefazodone, tryptophan), discontinue other serotonergics at least 2 wk before SSRI therapy |
| Pregnancy | C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus |
| Precautions | Caution in hepatic impairment and history of seizures; MAOIs should be discontinued at least 14 d before start of therapy; FDA recently recommended that all antidepressants should be used with caution in children and adolescents because of an association with increased suicidal ideation |
| Drug Name | Sertraline (Zoloft) |
|---|---|
| Description | Selectively inhibits presynaptic 5HT reuptake. Approved for obsessive-compulsive disorder in children >6 y. |
| Adult Dose | 50-200 mg/d PO |
| Pediatric Dose | <6 years: Not established >6 years: 25-100 mg/d PO |
| Contraindications | Documented hypersensitivity; MAOI use within 2 wk |
| Interactions | Inhibits CYP3A3/4, CYP2C9, CYP2C19, and CYP2D6, possibly decreasing clearance of isoenzyme substrates (eg, metoprolol, thioridazine, imipramine, haloperidol, phenytoin, barbiturates, glyburide, warfarin); increases toxicity of MAOIs, diazepam, tolbutamide, and warfarin; 5HT syndrome (ie, myoclonus, rigidity, confusion, nausea, hyperthermia, autonomic instability, coma, eventual death) occurs with simultaneous use of other serotonergics (eg, anorectics, tramadol, buspirone, trazodone, clomipramine, nefazodone, tryptophan); discontinue other serotonergics at least 2 wk before SSRI therapy |
| Pregnancy | C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus |
| Precautions | Caution in preexisting seizure disorders and recent myocardial infarction, unstable heart disease, or hepatic or renal impairment; volume depletion or diuretic use may cause hyponatremia (especially in elderly); FDA recently urged that all antidepressants should be used with caution in children and adolescents because of association with increased suicidal ideation; decreased libido possible in male adolescents |
| Drug Name | Fluvoxamine (Luvox) |
|---|---|
| Description | Potent selective inhibitor of neuronal 5HT reuptake. Does not notably bind to alpha-adrenergic, histamine, or cholinergic receptors and therefore has fewer adverse effects than tricyclic antidepressants. Many antidepressants available, but SSRIs provide many advantages. MAOIs should be avoided in mood disorders with depressive features; lethal if patient relapses from abstinence and combines them with cocaine. Approved for obsessive-compulsive disorder in children >8 y. |
| Adult Dose | 50-300 mg/d PO |
| Pediatric Dose | <8 years: Not established 8-17 years: 25 mg PO initially as single dose qhs; increase dose in 25-mg increments q4-7d as tolerated, until maximum therapeutic benefit achieved; divide total daily doses >50 mg into 2 doses; if divided doses not equal, administer large dose qhs; not to exceed 200 mg/d |
| Contraindications | Documented hypersensitivity; MAOI use within 2 wk; concurrent administration of terfenadine, astemizole, or cisapride |
| Interactions | Risk of a hypertensive crisis increases with coadministration of MAOIs; potentiates effect of triazolam and alprazolam (when taken concurrently, reduce dose by >50%); reduce dose of theophylline by one third and monitor plasma levels if taken concurrently; alcohol, cimetidine, sertraline, phenothiazines, and warfarin increase toxicity; 5HT syndrome (ie, myoclonus, rigidity, confusion, nausea, hyperthermia, autonomic instability, coma, eventual death) occurs with simultaneous use of other serotonergics (eg, anorectic agents, tramadol, buspirone, trazodone, clomipramine, nefazodone, tryptophan), discontinue other serotonergics at least 2 wk before SSRI therapy |
| Pregnancy | C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus |
| Precautions | Caution in liver dysfunction or cardiovascular disease and history of seizures or suicidal tendencies; FDA recently urged that all antidepressants should be used with caution in children and adolescents because of association with increased suicidal ideation |
These agents are structurally related to the phenothiazine antipsychotic agents and have 3 major pharmacologic actions in varying degrees: inhibition of the amine pump, sedation, and peripheral and central anticholinergic action. These drugs inhibit the reuptake of norepinephrine or 5HT (ie, 5-hydroxytryptamine) at the presynaptic neuron.
| Drug Name | Clomipramine (Anafranil) |
|---|---|
| Description | Affects 5HT uptake while its metabolite desmethylclomipramine affects norepinephrine uptake. Approved for obsessive-compulsive disorder in children >10 y. |
| Adult Dose | 100-250 mg/d PO |
| Pediatric Dose | >10 years: 25-200 mg/d PO; not to exceed 3 mg/kg/d |
| Contraindications | Documented hypersensitivity; cardiac conduction abnormalities; concurrent MAOI therapy |
| Interactions | May increase effect of CNS stimulants, CNS depressants, MAOIs, sympathomimetics, alcohol, antipsychotics, benzodiazepines, barbiturates, anticholinergic agents, thyroid medications (cardiac effects), or phenytoin; may decrease effect of clonidine and guanethidine; phenothiazines, methylphenidate, PO contraceptives (estrogen), or marijuana may increase effects; lithium, barbiturates, chloral hydrate, or smoking may decrease effects |
| Pregnancy | C - Safety for use during pregnancy has not been established. |
| Precautions | In general, not used during pregnancy; caution in seizure disorder (may lower seizure threshold); may exacerbate psychosis; caution in severe cardiopulmonary or renal impairment and those unable to metabolize sorbitol; adults or children with major depressive disorder (MDD) may have worsening of depression and/or emergence of suicidal ideation and behavior (suicidality) or unusual changes in behavior, whether or not they are taking antidepressants |
Childhood Habit Behaviors and Stereotypic Movement Disorder excerpt
Article Last Updated: May 3, 2006