poison centers’ experience with methylphenidate abuse in pre-teens and adolescents

Methylphenidate is the psychotherapeutic drug most fre-quently prescribed for the management of attention-deficit/hyperactivity disorder (ADHD) in children andadolescents (Goldman et al., 1998). Methylphenidate isalso used in the treatment of narcolepsy, Tourette’s syn-drome, and depression. Approximately 2.8% of children5 to 18 years of age were prescribed methylphenidate in1995 (Safer et al., 1996). From the early to mid-1990s,a 2.5-fold increase in prevalence of methylphenidate usein 5- to 18-year-olds and a 1.7- to 3.1-fold increase inprevalence of use in 2- to 4-year-old children were observed(Safer et al., 1996; Zito et al., 2000).

Methylphenidate is a phenylethylamine with a struc-ture and pharmacological properties similar to those of

amphetamine. Methylphenidate affects several neuro-transmitters including dopamine, norepinephrine, andserotonin. Methylphenidate’s effect in ADHD is mostlikely related to its activity on dopaminergic areas of thebrain (Challman and Lipsky, 2000). Methylphenidateincreases extracellular dopamine by binding to a dopaminetransporter which blocks reuptake of dopamine. Althoughmethylphenidate and cocaine have almost identical regionaldistribution and receptor binding sites in the brain, dif-ferences in duration of peak brain drug concentrationsand rates of egress from the brain may explain the lowerincidence of abuse of methylphenidate compared withcocaine (Volkow et al., 1995).

The abuse potential of methylphenidate has been rec-ognized for years. One of the first reports of methyl-phenidate abuse involved a patient who ingested 125tablets daily (Roux, 1960). In 1971, a clinical study foundthat physiological, subjective, and behavioral effects ofmethylphenidate were similar to those of amphetamines(Martin et al., 1971). Analysis of 60 animal and humanstudies found that in 48 studies (80.0%), methylpheni-date’s reinforcing, discriminative-stimulus, or subjectiveeffects were comparable with those of d-amphetamine orcocaine (Kollins et al., 2001). Methylphenidate func-

Accepted October 26, 2002.From the Maryland Poison Center, University of Maryland School of Pharmacy,

Baltimore.Presented at the North American Congress of Clinical Toxicology, Montreal,

October 8, 2001.The authors thank Annette Salliey for assistance with importing AAPCC TESS

data from D-base files into Access and preparing data for analysis.Reprint requests to Dr. Klein-Schwartz, Maryland Poison Center, 20 N. Pine

Street, Baltimore, MD 21201; e-mail: [email protected]/03/4203–0288�2003 by the American Academy of Child

and Adolescent Psychiatry.DOI: 10.1097/01.CHI.0000037040.04952.FC

Poison Centers’ Experience With Methylphenidate Abuse in Pre-Teens and Adolescents

WENDY KLEIN-SCHWARTZ, PHARM.D., M.P.H., AND JEAN MCGRATH, PHARM.D.

ABSTRACT

Objective: To evaluate trends and toxicity of methylphenidate abuse in pre-teens and adolescents reported to poison

centers. Method: The 1993–1999 American Association of Poison Control Centers Toxic Exposure Surveillance System

was queried for methylphenidate abuse cases in children aged 10 through 19 years that were followed to known out-

come. Main outcome measures included number of cases annually, toxicity, management site, and coded medical out-

come. Results: Of 759 cases, 42.7% involved 10- through 14-year-olds. For the 530 (70.0%) cases involving methylphenidate

only, the frequency increased sevenfold from 1993 to 1999. Of 570 patients (75.1%) managed in a health care facility, 398

were discharged from the emergency department and 172 were admitted. Symptoms occurred more commonly in expo-

sures involving coingestants (84.3%) than in methylphenidate-only exposures (71.1%).The most common symptoms in

adolescents with methylphenidate only were tachycardia (31.7%), agitation/irritability (25.7%), and hypertension (11.5%).

Outcomes were no effect in 189 cases (24.9%) and mild, moderate, and severe in 318 (41.9%), 245 (32.3%), and 7

(0.9%) patients, respectively. Conclusions: Poison center data demonstrate increasing frequency of methylphenidate abuse.

While the majority of adolescents experienced clinical effects and were managed in a health care facility, outcomes were

good, especially in cases involving methylphenidate only. J. Am. Acad. Child Adolesc. Psychiatry, 2003, 42(3):288–294.

Key Words: methylphenidate, adolescents, abuse.

288 J . AM. ACAD. CHILD ADOLESC. PSYCHIATRY, 42 :3 , MARCH 2003

tioned as a reinforcer, a strong predictor of abuse poten-tial, in non–drug-abusing volunteers (Rush et al., 2001).

Methylphenidate is abused orally, intranasally by crush-ing the tablets and snorting the powder, or parenterallyby dissolving the powder in water and injecting it. Oralabuse is more common when the drug is used to stayawake, while intranasal and intravenous use induceseuphoria (Weiner, 2000). Acute stimulant effects aremarkedly less pronounced with sustained-release formu-lations, suggesting that these products have lower abusepotential (Jaffe, 2002; Kollins et al., 1998). Publishedreports in adolescents include two cases of oral methyl-phenidate abuse in 11- and 13-year-old boys (Corrigalland Ford, 1996; Goyer et al., 1979) and three cases ofintranasal abuse in 15-, 16-, and 19-year-old boys (Garland,1998; Jaffe, 1991; Massello and Carpenter, 1999).

The extent to which adolescents are abusing methyl-phenidate is unknown. There is concern that while theprevalence of abuse is relatively low, the problem is grow-ing. In 2000, the Community Epidemiology Work Groupof the National Institute on Drug Abuse reported emerg-ing trends in methylphenidate abuse in several major U.S.metropolitan areas (http://www.nida.nih.gov/Infofax/ritalin.html; accessed 4/24/02). The Monitoring the Futuresurvey found that the annual prevalence of nonmedici-nal use of methylphenidate by high school seniors peakedat 2.8% in 1997 and 1998 compared with 0.1% in 1992(Johnston et al., 2001). These figures then dropped to2.4% in 1999 and 2.2% in 2000. The Drug Abuse WarningNetwork reported 1,727 emergency department methyl-phenidate mentions in 1998 compared with 271 in 1990(http://www.samhsa.gov/oas/dawn.htm; accessed 12/19/01).Of the 1,727 mentions in 1998, 56% involved patients10 to 17 years of age. A survey of 6,000 public schoolstudents in Massachusetts found that 13% of high schoolstudents and 4% of seventh and eighth graders reportedhaving used methylphenidate without a prescription atsome time in their lives (http://familyeducation.com/article/0,1120,2-20061-0-1,00.html?yah; accessed 4/24/02).

Methylphenidate is difficult to synthesize, so the pri-mary source of drug for abuse is probably drug diversionrather than manufacture. In a survey of students takingmethylphenidate therapeutically, 16% indicated that otherstudents had asked them to trade, sell, or give them theirmedication (Musser et al., 1998). According to the DrugEnforcement Administration, there are reports of methyl-phenidate theft at unregistered locations such as schoolsand homes (http://www.usdoj.gov/dea/pubs/cngrtest/

ct051600.htm; accessed 12/19/01). In case reports, ado-lescents with ADHD were stealing from the home sup-ply or from the school nurse’s cabinet (Corrigall and Ford,1996; Garland, 1998; Goyer et al., 1979; Jaffe, 1991).

Despite concerns that adolescent abuse of methyl-phenidate is increasing, there are only five previouslyreported cases involving adolescent boys ranging in agefrom 11 through 19 years (Corrigall and Ford, 1996;Garland, 1998; Goyer et al., 1979; Jaffe, 1991; Masselloand Carpenter, 1999). Of 30 methylphenidate cases inadolescents 13 through 19 years of age reported to aregional poison center in 1998, 11 (36.7%) were the resultof drug abuse (Foley et al., 2000).

Poison centers in the United States manage more than2 million potentially toxic exposures annually (Litovitzet al., 2001). Exposure cases are reported to the AmericanAssociation of Poison Control Centers (AAPCC) ToxicExposure Surveillance System (TESS). This study eval-uates pre-teen and adolescent methylphenidate abusereported to AAPCC TESS. The objectives were to assessfor trends and to evaluate the toxicity and outcome ofmethylphenidate abuse in this population. The hypoth-esis was that the frequency of methylphenidate abusewould increase during the study period.

METHOD

The AAPCC TESS was searched for methylphenidate exposuresin children and adolescents reported to poison centers between 1993and 1999. During the 7-year study period there was an average of 64poison centers, with a service area of 70% to 97% of the United States,submitting data annually. When a call comes into a poison center, thespecialist in poison information determines the circumstances of theexposure, consults resources, and provides triage and treatment rec-ommendations. The specialist enters the case into a database withnumerous fields relating to the patient, the substance involved, man-agement, and outcome. The reason for the exposure is a field to whichthe specialist assigns 1 of 18 possible reason codes based on the cir-cumstances of the exposure. The term exposure is used to distinguishcases in which an individual used the drug from general informationcalls about the drug.

Inclusion criteria were ages 10 through 19 years, reason for theexposure coded as intentional abuse, and known medical outcome.Exposures to methylphenidate with or without other substances wereincluded. Intentional abuse is defined as an exposure resulting fromthe intentional improper or incorrect use of the substance where thesubject was likely attempting to gain a high, euphoric effect or someother psychotropic effect. Examples of intentional abuse would includean adolescent not prescribed methylphenidate who uses it recreationallyor an adolescent taking methylphenidate on a long-term basis whotakes extra doses or snorts or injects it to get high. Known medicaloutcomes include no effect, minor effect, moderate effect, major effect,and death; definitions for these outcomes have been previously pub-lished (Litovitz et al., 2001). Cases without follow-up were excluded.

METHYLPHENIDATE ABUSE

J . AM. ACAD. CHILD ADOLESC. PSYCHIATRY, 42 :3 , MARCH 2003 289

KLEIN-SCHWARTZ AND McGRATH


Data were analyzed using Microsoft Access� (Microsoft Corp.,Seattle), and statistical comparisons between groups were performedwith the two-tailed χ2 test. Summary statistics were generated forexposure frequency, chronicity, exposure route, clinical effects, man-agement site, therapy, and medical outcome. Route of exposure wasanalyzed for exposures to methylphenidate as the sole substance sincefor multiple substance exposures it is not possible to match the routewith each individual substance. Ages were categorized into two groups:10 through 14 years of age and 15 through 19 years of age. The AAPCCTESS chronicity field includes acute, acute-on-chronic, or chronic.A case would be coded as acute if an adolescent not prescribed methyl-phenidate uses it one or more times over a period of 8 hours or less.A case would be coded as acute-on-chronic exposure if an adolescentwho is taking methylphenidate therapeutically takes methylpheni-date in a single, larger than prescribed dose or by a route other thanoral. A case would be coded as chronic if an adolescent is repeatedlytaking methylphenidate for more than 8 hours. An example of achronic exposure would be intentional ingestion of larger than pre-scribed doses of methylphenidate over a period of days or weeks.

The study was reviewed by the University of Maryland BaltimoreInstitutional Review Board and determined to be exempt from theIRB approval process.

RESULTS

During the 7-year study period, a total of 11,149 methyl-phenidate exposures in children and adolescents 10 through19 years of age were reported to poison centers. The rea-son for exposure was intentional abuse in 1,244 (11.2%)cases. Excluding abuse cases with unknown outcomes,759 cases comprised the final study population, of which324 (42.7%) involved 10- through 14-year-olds. Overall66.4% of exposures occurred in 13- through 16-year-olds, with age distribution showing a peak at 14 through15 years (Fig. 1). Males accounted for 58.9% of cases.

Of the 759 cases, 530 (70.0%) involved methylpheni-date as the sole substance. The majority (93.0%) of expo-sures involving substances in addition to methylphenidateinvolved one or two other substances. Methylphenidate-only exposures were more common in children aged 10through 14 years than in 15- through 19-year-olds (77.2%versus 64.4% sole substance, respectively) (χ2

1 = 14.4, p <.001) (Table 1). The number of cases involving methyl-phenidate as a single substance increased sevenfold from1993 to 1999 (Fig. 2).

Analysis of route of exposure showed that most pre-teens and teenagers abused methylphenidate by a singleroute only, although in some cases more than one routewas involved (Table 2). For exposures involving methyl-phenidate only, the most common route of exposure wasingestion.

The exposure was acute in most cases, with only 117(15.4%) cases coded as acute-on-chronic or chronic. Forchildren 10 through 14 years old, acute-on-chronic orchronic exposures occurred in 40 (12.3%) cases com-pared with 77 cases (17.7%) in 15- through 19-year-olds(χ2

1 = 4.1, p < .05).There were 189 cases managed outside a health care

facility, either at a residence or other site (Table 1). Patientswith exposures involving methylphenidate plus other sub-stances were more likely to be managed in a health carefacility (85.6%) than patients with exposure to methyl-phenidate only (70.6%) (χ2

1 = 19.3, p < .001). Afteremergency department treatment, patients with methyl-phenidate plus other substances were more likely to be

Fig. 1 Frequency of methylphenidate exposures by age.



admitted (37.8%) than patients exposed to methyl-phenidate only (26.2%) (χ2

1 = 8.2, p < .01).Clinical toxicity occurred more commonly in expo-

sures involving methylphenidate plus other substances(84.3%) than in methylphenidate-only exposures (71.1%)(χ2

1 = 14.8, p < .001). The most common clinical effectsin cases involving methylphenidate only were tachycar-dia (31.7%), agitation/irritability (25.7%), and hyper-tension (11.5%). There was one case of ventriculartachycardia/fibrillation and eight complaints of chestpain. No seizures were reported.

Table 3 compares the outcomes of exposures involv-ing methylphenidate only with outcomes of exposuresinvolving methylphenidate with other substances. Twothirds of pre-teens and adolescents had no effect or expe-

rienced only minor toxicity. All of the major outcomesoccurred in 15- through 19-year-olds.

DISCUSSION

Overall, methylphenidate abuse accounted for 11.2%of methylphenidate cases in pre-teens and adolescentsreported to poison centers during the 7-year study period.These data showed increasing occurrence of methylphen-idate abuse, with 158 cases in 1999 compared with only17 cases in 1993. The largest number of cases (203) occurredin 1998. The drop in cases in 1999 compared with 1998is similar to the trend of decreasing annual prevalence ofnonmedicinal use in 1999 and 2000 compared with 1997and 1998 reported in the Monitoring the Future survey

TABLE 1Management Site by Age Group

Treated/Released HCF

Home From ED Admission Other Total

10–14 yearsMethylphenidate only 61 137 33 19 250Methylphenidate + other substances 5 45 19 5 74Subtotal 66 (20.4%) 182 (56.2%) 52 (16.0%) 24 (7.4%) 324 (100%)

15–19 yearsMethylphenidate only 52 139 65 24 280Methylphenidate + other substances 6 77 55 17 155Subtotal 58 (13.3%) 216 (50.0%) 120 (27.6%) 41 (9.4%) 435 (100%)

Total 124 (16.3%) 398 (52.4%) 172 (22.7%) 65 (8.6%) 759 (100%)

Note: % is row percent. ED = emergency department; HCF = health care facility.

Fig. 2 Trends in methylphenidate abuse exposures.



(Johnston et al., 2001). These findings suggest that poi-son center data can augment other surveillance tools usedto prospectively follow trends in substance abuse.

Over the 7-year study period, total exposures to phar-maceutical and nonpharmaceutical substances reportedto AAPCC TESS increased approximately 30% com-pared with the ninefold increase in all methylphenidateabuse cases and sevenfold increase in methylphenidate-only cases in pre-teens and adolescents. Therapeutic usedata demonstrate similar trends of increasing prevalenceof use of methylphenidate and other stimulants, althoughthe rate of increase is generally lower than for the poisoncenter abuse data reported here. Using several popula-tion-based databases, Safer et al. (1996) reported an aver-age 2.5-fold increase in prevalence of methylphenidateuse between 1990 and 1995. A comparison of nationalmedication use data in 1996 and 1987 found that ratesof stimulant use increased 3.5-fold in 6- through 14-year-olds and 10.4-fold in 15- through 18-year-olds (Olfsonet al., 2002). Rushton and Whitmire (2001) reported a2.2-fold increase in stimulant prescription prevalence in

6- through 14-year-olds in 1998 compared with 1992.Inasmuch as methylphenidate accounts for more than90% of stimulant use for ADHD in the United States,it is reasonable to assume that these figures reflect anincrease in methylphenidate use (Goldman et al., 1998).The difference in magnitude of trends in therapeutic usedata and poison center abuse data is in part related to thefact that most therapeutic use data include younger school-age children (under 10 years of age), a group less likelyto be involved in substance abuse.

This study found that most pre-teens and adolescentsabusing methylphenidate were not prescribed the drug.Approximately 85% of cases were coded as acute, indi-cating that methylphenidate was usually not the child’smedication. This finding varies somewhat from case reportsin adolescents and may reflect an undercount of chronic-ities other than acute as a result of the limited informa-tion available by telephone to specialists in poisoninformation. However, these findings are consistent withreports that students on methylphenidate are asked fortheir medication by other students (Musser et al., 1998).

TABLE 2Methylphenidate-Only Exposures: Routes

10–14 15–19Routes Years Old Years Old Total

Ingestion only 214 (85.6%) 208 (74.3%) 422 (79.6%)Nasal only 31 (12.4%) 61 (21.8%) 92 (17.4%)Parenteral only 0 1 (0.4%) 1 (0.2%)Ingestion

& nasal 5 (2.0%) 7 (2.5%) 12 (2.3%)Ingestion

& parenteral 0 1 (0.4%) 1 (0.2%)Nasal & parenteral 0 1 (0.4%) 1 (0.2%)Nasal & unknown 0 1 (0.4%) 1 (0.2%)

Total 250 (100%) 280 (100%) 530 (100%)

Note: % is column percent.

TABLE 3Medical Outcome by Age Group

No Effect Minor Moderate Major Total

10–14 yearsMethylphenidate only 85 (34.0%) 98 (39.2%) 67 (26.8%) 0 250Methylphenidate + other substances 13 (17.6%) 41 (55.4%) 20 (27.0%) 0 74

15–19 yearsMethylphenidate only 68 (24.9%) 111 (39.6%) 100 (35.7%) 1 (0.4%) 280Methylphenidate + other substances 23 (14.8%) 68 (43.9%) 58 (37.4%) 6 (3.9%) 155

Total 189 318 245 7 759

Note: % is row percent.

Further investigation into the source of drug is importantfor understanding patterns of prescription drug abuse byadolescents as well as for devising intervention strategies.

Outcome measures included clinical effects, manage-ment site, and coded medical outcome. Despite the factthat clinical toxicity was experienced by the majority ofsubjects and most cases were managed in a health carefacility, medical outcomes were good. Major toxic effectsoccurred in seven adolescents, of which six exposuresinvolved substances in addition to methylphenidate.Although 75% of patients were managed in the emer-gency department, only 30% were admitted. In 71% ofcases involving methylphenidate only, clinical effects includ-ing cardiovascular (tachycardia, hypertension) and CNS(agitation/irritability) toxicity developed. However, amongthe symptomatic patients with methylphenidate-onlyexposures, 55% experienced minor toxicity and 44% mod-erate toxicity. Only one adolescent with methylphenidatealone developed major effects, and there were no deaths.Fatalities have been reported in adults but are uncommon.There is one death reported in a 19-year-old who suffereda cardiopulmonary arrest and died after intranasal abusewith friends at a party (Massello and Carpenter, 1999).

Differences were observed between the younger (10-through 14-year-olds) and older (15- through 19-year-olds) methylphenidate abusers. For older adolescents,concomitant use of other substances occurred more often,the proportion admitted to the health care facility washigher, and medical outcomes were more serious. Olderadolescents exhibited a higher frequency of acute-on-chronic and chronic methylphenidate use than 10- through14-year-olds. Although ingestion was the most frequentlyreported route in both age groups, the older adolescentswere more likely to report other routes, especially nasal.

Limitations

Several limitations should be considered in interpret-ing the results of this study. The study is retrospective.Given the large increase in prevalence of methylpheni-date use, one might have expected an even larger numberof abuse cases reported to poison centers over the 7-yearstudy period. Reporting bias may be a factor because report-ing to poison centers is voluntary and it is not possible toassess how cases not reported are different from those thatare reported. It is possible that cases involving abuse areless likely to be reported to poison centers than other typesof exposures (e.g., suicide attempts). How individual spe-cialists in poison information interpret the definition of

intentional abuse may impact coding of the reason field.The AAPCC TESS definition of intentional abuse differsfrom the DSM-IV definition in that a pattern of repeatedsubstance abuse is not required. There are no dose data.

Clinical Implications

This study provides further documentation of thepotential for methylphenidate abuse and its clinical man-ifestations. Poison center data demonstrate a trend ofincreasing abuse of methylphenidate by pre-teens andadolescents. With increasing therapeutic use of methyl-phenidate, there is cause for concern that the prevalenceof abuse will continue to rise. Rational prescribing caninclude consideration of the appropriateness of the drugfor a given teenager as well as prescribing newer, sus-tained-release methylphenidate products, which may haveless abuse potential, for those teenagers for whom abuseis a concern. Clinicians should help establish clear pro-cedures for administration and supervision of the ado-lescent’s access to the medication. Physicians and pharmacistsshould be alert for frequent requests for new prescrip-tions for pre-teens and adolescents, in order to limit non-therapeutic drug access. Parents and school nurses shouldalso be aware of the potential for abuse or misuse and beeducated regarding appropriate dosing and storage. Allchildren taking methylphenidate therapeutically shouldbe cautioned against sharing medication with friends.

REFERENCES

Challman TD, Lipsky JJ (2000), Methylphenidate: its pharmacology and uses.Mayo Clin Proc 75:711–721

Corrigall R, Ford T (1996), Methylphenidate euphoria. J Am Acad ChildAdolesc Psychiatry 35:1421

Foley R, Mrvos R, Krenzelok EP (2000), A profile of methylphenidate expo-sures. J Toxicol Clin Toxicol 38:625–630

Garland EJ (1998), Intranasal abuse of prescribed methylphenidate. J AmAcad Child Adolesc Psychiatry 37:573–574

Goldman LS, Genel M, Bezman RJ, Slanetz PJ (1998), Diagnosis and treat-ment of attention-deficit/hyperactivity disorder in children and adoles-cents. JAMA 279:1100–1107

Goyer PF, Davis GC, Rapoport JL (1979), Abuse of prescribed stimulant med-ication by a 13-year-old hyperactive boy. J Am Acad Child Psychiatry 18:170–175

Jaffe SL (1991), Intranasal abuse of prescribed methylphenidate by an alco-hol and drug abusing adolescent with ADHD. J Am Acad Child AdolescPsychiatry 30:773–775

Jaffe SL (2002), Failed attempts at intranasal abuse of Concerta (letter). J AmAcad Child Adolesc Psychiatry 41:5

Johnston LD, O’Malley PM, Bachman JG (2001), Monitoring the FutureNational Survey Results on Drug Abuse, 1975–2000, Vol 1: Secondary SchoolStudents (NIH Publication 01-4924). Bethesda, MD: National Instituteon Drug Abuse, pp 1–519

Kollins SH, MacDonald EK, Rush CR (2001), Assessing the abuse potentialof methylphenidate in nonhuman and human subjects: a review. PharmacolBiochem Behav 68:611–627





Kollins SH, Rush CR, Pazzaglia PJ, Ali JA (1998), Comparison of acute behav-ioral effects of sustained-release and immediate-release methylphenidate.Exp Clin Psychopharmacol 6:367–374

Litovitz TL, Klein-Schwartz W, White S et al. (2001), 2000 Annual Reportof the American Association of Poison Control Centers Toxic ExposureSurveillance System. Am J Emerg Med 19:337–395

Martin WR, Sloan JW, Sapira BD, Jasinski DR (1971), Physiologic, subjec-tive, and behavioral effects of amphetamine, methamphetamine, ephedrine,phenmetrazine and methylphenidate in man. Clin Pharmacol Ther 12:245–258

Massello W, Carpenter DA (1999), A fatality due to the intranasal abuse ofmethylphenidate (Ritalin). J Forensic Sci 44:220–221

Musser CJ, Ahmann PA, Theye FW, Mundt P, Broste SK, Mueller-Rizner N(1998), Stimulant use and the potential abuse in Wisconsin as reportedby school administrators and longitudinally followed children. J Dev BehavPediatr 19:187–192

Olfson M, Marcus SC, Weissman MM, Jensen PS (2002), National trends inthe use of psychotropic medications in children. J Am Acad Child AdolescPsychiatry 41:514–521

Roux B (1960), Is Ritalin an addiction-producing drug? Dis Nerv Syst 21:346–349Rush CR, Essman WD, Simpson CA, Baker RW (2001), Reinforcing and

subject-related effects of methylphenidate and d-amphetamine in non–drug-abusing humans. J Clin Pyschopharmacol 21:273–286

Rushton JL, Whitmire JT (2001), Pediatric stimulant and selective serotoninreuptake inhibitor prescription trends 1992 to 1998. Arch Pediatr AdolescMed 155:560–565

Safer DJ, Zito JM, Fine EM (1996), Increased methylphenidate usage forattention deficit disorder in the 1990s. Pediatrics 98:1084–1088

Volkow ND, Ding YS, Fowler JS et al. (1995), Is methylphenidate like cocaine?Studies on their pharmacokinetics and distribution in the human brain.Arch Gen Psychiatry 52:456–463

Weiner AL (2000), Emerging drugs of abuse in Connecticut. Conn Med64:19–23

Zito JM, Safer DJ, dosReis S, Gardner JF, Boles M, Lynch F (2000), Trendsin the prescribing of psychotropic medications to preschoolers. JAMA238:1025–1030

poison centers’ experience with methylphenidate abuse in pre-teens and adolescents

Documents