Marijuana: Know the Facts

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Whatismarijuana?

Imageby©iStock.com/nicoolay

Marijuana—alsocalledweed,herb,pot,grass,bud,ganja,MaryJane,anda

vastnumberofotherslangterms—isagreenish-graymixtureofthe

driedflowersofCannabissativa.Somepeoplesmokemarijuanainhand-rolled

cigarettescalledjoints;inpipes,waterpipes(sometimescalledbongs),or

inblunts(marijuanarolledincigarwraps)Marijuanacanalsobeusedtobrewtea

and,particularlywhenitissoldorconsumedformedicinalpurposes,isfrequently

mixedintofoods(edibles)suchasbrownies,cookies,orcandies.Vaporizersare

alsoincreasinglyusedtoconsumemarijuana.Strongerformsofmarijuana

includesinsemilla(fromspeciallytendedfemaleplants)andconcentratedresins

containinghighdosesofmarijuana’sactiveingredients,includinghoneylikehash

oil,waxybudder,andhardamberlikeshatter.Theseresinsareincreasingly

popularamongthosewhousethembothrecreationallyandmedically.

Themainpsychoactive(mind-altering)chemicalinmarijuana,responsiblefor

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mostoftheintoxicatingeffectsthatpeopleseek,isdelta-9-tetrahydrocannabinol�(THC).Thechemicalisfoundinresinproducedbytheleavesandbuds

primarilyofthefemalecannabisplant.Theplantalsocontainsmorethan500

otherchemicals,includingmorethan100compoundsthatarechemicallyrelated

toTHC,calledcannabinoids

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Whatisthescopeofmarijuanausein

theUnitedStates?

Marijuanaisthemostcommonlyusedillicitdrug(22.2millionpeoplehaveused

itinthepastmonth)accordingtothe2015NationalSurveyonDrugUseand

Health.� Itsuseismoreprevalentamongmenthanwomen—agendergapthat

17.

Itisunknownwhetherthisincreaseisduetoincreaseduse,

increasedpotencyofmarijuana(amountofTHCitcontains),orotherfactors.It

shouldbenoted,however,thatmentionsofmarijuanainmedicalrecordsdonot

necessarilyindicatethattheseemergenciesweredirectlyrelatedtomarijuana

intoxication.

widenedintheyears2007to2014.

Marijuanauseiswidespreadamongadolescentsandyoungadults.Accordingto

theMonitoringtheFuturesurvey—anannualsurveyofdruguseandattitudes

amongtheNation’smiddleandhighschoolstudents—mostmeasuresof

marijuanauseby8th,10th,and12thgraderspeakedinthemid-to-late1990sand

thenbeganaperiodofgradualdeclinethroughthemid-2000sbeforelevellingoff.

Mostmeasuresshowedsomedeclineagaininthepast5years.Teens’

perceptionsoftherisksofmarijuanausehavesteadilydeclinedoverthepast

decade,possiblyrelatedtoincreasingpublicdebateaboutlegalizingorloosening

restrictionsonmarijuanaformedicinalandrecreationaluse.In2016,9.4percent

of8thgradersreportedmarijuanauseinthepastyearand5.4percentinthepast

month(currentuse).Among10thgraders,23.9percenthadusedmarijuanainthe

pastyearand14.0percentinthepastmonth.Ratesofuseamong12thgraders

werehigherstill:35.6percenthadusedmarijuanaduringtheyearpriortothe

surveyand22.5percentusedinthepastmonth;6.0percentsaidtheyused

marijuanadailyornear-daily.

Medicalemergenciespossiblyrelatedtomarijuanausehavealsoincreased.The

DrugAbuseWarningNetwork(DAWN),asystemformonitoringthehealthimpact

ofdrugs,estimatedthatin2011,therewerenearly456,000drug-related

emergencydepartmentvisitsintheUnitedStatesinwhichmarijuanausewas

mentionedinthemedicalrecord(a21percentincreaseover2009).Abouttwo-

thirdsofpatientsweremaleand13percentwerebetweentheagesof12and

8

Whataremarijuanaeffects?

Whenmarijuanaissmoked,THCandotherchemicalsintheplantpassfromthe

lungsintothebloodstream,whichrapidlycarriesthemthroughoutthebodyto

thebrain.Thepersonbeginstoexperienceeffectsalmostimmediately(see

"Howdoesmarijuanaproduceitseffects?").Manypeopleexperiencea

pleasanteuphoriaandsenseofrelaxation.Othercommoneffects,whichmay

varydramaticallyamongdifferentpeople,includeheightenedsensory

perception(e.g.,brightercolors),laughter,alteredperceptionoftime,and

increasedappetite.

Ifmarijuanaisconsumedinfoodsorbeverages,theseeffectsaresomewhat

delayed—usuallyappearingafter30minutesto1hour—becausethedrugmust

firstpassthroughthedigestivesystem.Eatingordrinkingmarijuanadelivers

significantlylessTHCintothebloodstreamthansmokinganequivalentamount

oftheplant.Becauseofthedelayedeffects,peoplemayinadvertentlyconsume

moreTHCthantheyintendto.

Pleasantexperienceswithmarijuanaarebynomeansuniversal.Insteadof

relaxationandeuphoria,somepeopleexperienceanxiety,fear,distrust,or

panic.Theseeffectsaremorecommonwhenapersontakestoomuch,the

marijuanahasanunexpectedlyhighpotency,orthepersonisinexperienced.

Peoplewhohavetakenlargedosesofmarijuanamayexperienceanacute

psychosis,whichincludeshallucinations,delusions,andalossofthesenseof

personalidentity.Theseunpleasantbuttemporaryreactionsaredistinctfrom

longer-lastingpsychoticdisorders,suchasschizophrenia,thatmaybe

associatedwiththeuseofmarijuanainvulnerableindividuals.(See"Istherea

linkbetweenmarijuanauseandpsychiatricdisorders?")

AlthoughdetectableamountsofTHCmayremaininthebodyfordaysoreven

weeksafteruse,thenoticeableeffectsofsmokedmarijuanagenerallylastfrom

1to3hours,andthoseofmarijuanaconsumedinfoodordrinkmaylastfor

manyhours.

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Howdoesmarijuanaproduceits

effects?

THC’schemicalstructureissimilartothebrainchemicalanandamide.Similarity

instructureallowsthebodytorecognizeTHCandtoalternormalbrain

communication.

Endogenouscannabinoidssuchasanandamide(seefigure)functionas

neurotransmittersbecausetheysendchemicalmessagesbetweennervecells

(neurons)throughoutthenervoussystem.Theyaffectbrainareasthatinfluence

pleasure,memory,thinking,concentration,movement,coordination,and

sensoryandtimeperception.Becauseofthissimilarity,THCisabletoattachto

moleculescalledcannabinoidreceptorsonneuronsinthesebrainareasand

activatethem,disruptingvariousmentalandphysicalfunctionsandcausingthe

effectsdescribedearlier.Theneuralcommunicationnetworkthatusesthese

cannabinoidneurotransmitters,knownastheendocannabinoidsystem,playsa

ImagebytheNIDA

THC’schemicalstructureissimilartothebrainchemicalanandamide.Similarityin

structureallowsdrugstoberecognizedbythebodyandtoalternormalbrain

communication.

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criticalroleinthenervoussystem’snormalfunctioning,sointerferingwithitcan

haveprofoundeffects.

Forexample,THCisabletoalterthefunctioningofthehippocampus(see

"Marijuana,Memory,andtheHippocampus")andorbitofrontalcortex,brain

areasthatenableapersontoformnewmemoriesandshifthisorherattentional

focus.Asaresult,usingmarijuanacausesimpairedthinkingandinterfereswith

aperson’sabilitytolearnandperformcomplicatedtasks.THCalsodisrupts

functioningofthecerebellumandbasalganglia,brainareasthatregulate

balance,posture,coordination,andreactiontime.Thisisthereasonpeople

whohaveusedmarijuanamaynotbeabletodrivesafely(see"Doesmarijuana

useaffectdriving?")andmayhaveproblemsplayingsportsorengagingin

otherphysicalactivities.

Peoplewhohavetakenlargedosesofthedrugmayexperienceanacute

psychosis,whichincludeshallucinations,delusions,andalossofthesense

ofpersonalidentity.

THC,actingthroughcannabinoidreceptors,alsoactivatesthebrain’sreward

system,whichincludesregionsthatgoverntheresponsetohealthypleasurable

behaviorssuchassexandeating.Likemostotherdrugsthatpeoplemisuse,

THCstimulatesneuronsintherewardsystemtoreleasethesignalingchemical

dopamineatlevelshigherthantypicallyobservedinresponsetonaturalstimuli.

Thisfloodofdopaminecontributestothepleasurable"high"thatthoseusewho

recreationalmarijuanaseek.

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Diagramshowingdifferentpartsofthebrainanddescribingmarijuana'seffectsonthe

brain

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Doesmarijuanauseaffectdriving?

Photoby©iStock.com/MadCircles

Marijuanasignificantlyimpairsjudgment,motorcoordination,andreactiontime,

andstudieshavefoundadirectrelationshipbetweenbloodTHCconcentration

andimpaireddrivingability.

Marijuanaistheillicitdrugmostfrequentlyfoundinthebloodofdriverswhohave

beeninvolvedinvehiclecrashes,includingfatalones.TwolargeEuropean

studiesfoundthatdriverswithTHCintheirbloodwereroughlytwiceaslikelyto

beculpableforafatalcrashthandriverswhohadnotuseddrugsoralcohol�

However,theroleplayedbymarijuanaincrashesisoftenunclearbecauseitcan

bedetectedinbodyfluidsfordaysorevenweeksafterintoxicationandbecause

peoplefrequentlycombineitwithalcohol.Thoseinvolvedinvehiclecrasheswith

THCintheirblood,particularlyhigherlevels,arethreetoseventimesmorelikely

toberesponsiblefortheincidentthandriverswhohadnotuseddrugsoralcohol.

Theriskassociatedwithmarijuanaincombinationwithalcoholappearstobe

greaterthanthatforeitherdrugbyitself.

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Severalmeta-analysesofmultiplestudiesfoundthattheriskofbeinginvolved

inacrashsignificantlyincreasedaftermarijuanause—inafewcases,therisk

However,alargecase-controlstudydoubledormorethandoubled.

conductedbytheNationalHighwayTrafficSafetyAdministrationfoundno

significantincreasedcrashriskattributabletocannabisaftercontrollingfor

drivers’age,gender,race,andpresenceofalcohol.

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Ismarijuanaaddictive?

Marijuanausecanleadtothedevelopmentofproblemuse,knownasa

marijuanausedisorder,whichtakestheformofaddictioninseverecases.

Recentdatasuggestthat30percentofthosewhousemarijuanamayhavesome

degreeofmarijuanausedisorder.Peoplewhobeginusingmarijuanabeforethe

ageof18arefourtoseventimesmorelikelytodevelopamarijuanausedisorder

thanadults.

Marijuanausedisordersareoftenassociatedwithdependence—inwhicha

personfeelswithdrawalsymptomswhennottakingthedrug.Peoplewhouse

marijuanafrequentlyoftenreportirritability,moodandsleepdifficulties,

decreasedappetite,cravings,restlessness,and/orvariousformsofphysical

discomfortthatpeakwithinthefirstweekafterquittingandlastupto2

weeks.Marijuanadependenceoccurswhenthebrainadaptstolargeamountsof

thedrugbyreducingproductionofandsensitivitytoitsownendocannabinoid

neurotransmitters.

Marijuanausedisorderbecomesaddictionwhenthepersoncannotstopusing

thedrugeventhoughitinterfereswithmanyaspectsofhisorherlife.Estimates

ofthenumberofpeopleaddictedtomarijuanaarecontroversial,inpartbecause

epidemiologicalstudiesofsubstanceuseoftenusedependenceasaproxyfor

addictioneventhoughitispossibletobedependentwithoutbeingaddicted.

Thosestudiessuggestthat9percentofpeoplewhousemarijuanawillbecome

dependentonit,risingtoabout17percentinthosewhostartusingintheirteens.

In2015,about4.0millionpeopleintheUnitedStatesmetthediagnosticcriteria

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foramarijuanausedisorder; 138,000voluntarilysoughttreatmentfortheir

marijuanause.

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RisingPotency

Marijuanapotency,asdetectedinconfiscatedsamples,hassteadily

increasedoverthepastfewdecades.2Intheearly1990s,theaverageTHC

contentinconfiscatedmarijuanasampleswasroughly3.8percent.In2014,it

was12.2percent.Theaveragemarijuanaextractcontainsmorethan50

percentTHC,withsomesamplesexceeding80percent.Thesetrendsraise

concernsthattheconsequencesofmarijuanausecouldbeworsethaninthe

past,particularlyamongthosewhoarenewtomarijuanauseorinyoung

people,whosebrainsarestilldeveloping(see"Whataremarijuana’slong-

termeffectsonthebrain?").

Researchersdonotyetknowthefullextentoftheconsequenceswhenthe

bodyandbrain(especiallythedevelopingbrain)areexposedtohigh

concentrationsofTHCorwhethertherecentincreasesinemergency

departmentvisitsbypeopletestingpositiveformarijuanaarerelatedtorising

potency.Theextenttowhichpeopleadjustforincreasedpotencybyusing

lessorbysmokingitdifferentlyisalsounknown.Recentstudiessuggestthat

experiencedpeoplemayadjusttheamounttheysmokeandhowmuchthey

inhalebasedonthebelievedstrengthofthemarijuanatheyareusing,but

theyarenotabletofullycompensateforvariationsinpotency.

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Whataremarijuana'slong-term

effectsonthebrain?

Substantialevidencefromanimalresearchandagrowingnumberofstudiesin

humansindicatethatmarijuanaexposureduringdevelopmentcancauselong-

termorpossiblypermanentadversechangesinthebrain.RatsexposedtoTHC

beforebirth,soonafterbirth,orduringadolescenceshownotableproblemswith

specificlearningandmemorytaskslaterinlife.Cognitiveimpairmentsinadultrats

exposedtoTHCduringadolescenceareassociatedwithstructuralandfunctional

changesinthehippocampus.Studiesinratsalsoshowthatadolescentexposure

toTHCisassociatedwithanalteredrewardsystem,increasingthelikelihoodthat

ananimalwillself-administerotherdrugs(e.g.,heroin)whengivenanopportunity

(see"Ismarijuanaagatewaydrug?").

Imagingstudiesofmarijuana’simpactonbrainstructureinhumanshaveshown

conflictingresults.Somestudiessuggestregularmarijuanauseinadolescenceis

associatedwithalteredconnectivityandreducedvolumeofspecificbrainregions

involvedinabroadrangeofexecutivefunctionssuchasmemory,learning,and

impulsecontrolcomparedtopeoplewhodonotuse.Otherstudieshavenotfound

significantstructuraldifferencesbetweenthebrainsofpeoplewhodoanddonot

usethedrug.

Severalstudies,includingtwolargelongitudinalstudies,suggestthatmarijuana

usecancausefunctionalimpairmentincognitiveabilitiesbutthatthedegreeand/

ordurationoftheimpairmentdependsontheagewhenapersonbeganusing

andhowmuchandhowlongheorsheused.

Amongnearly4,000youngadultsintheCoronaryArteryRiskDevelopmentin

YoungAdultsstudytrackedovera25-yearperioduntilmid-adulthood,cumulative

lifetimeexposuretomarijuanawasassociatedwithlowerscoresonatestof

verbalmemorybutdidnotaffectothercognitiveabilitiessuchasprocessing

speedorexecutivefunction.Theeffectwassizeableandsignificantevenafter

eliminatingthoseinvolvedwithcurrentuseandafteradjustingforconfounding

factorssuchasdemographicfactors,otherdrugandalcoholuse,andother

psychiatricconditionssuchasdepression.

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AlargelongitudinalstudyinNewZealandfoundthatpersistentmarijuanause

disorderwithfrequentusestartinginadolescencewasassociatedwithalossof

anaverageof6orupto8IQpointsmeasuredinmid-adulthood.Significantly,in

thatstudy,thosewhousedmarijuanaheavilyasteenagersandquitusingas

adultsdidnotrecoverthelostIQpoints.Peoplewhoonlybeganusing

marijuanaheavilyinadulthooddidnotloseIQpoints.Theseresultssuggest

thatmarijuanahasitsstrongestlong-termimpactonyoungpeoplewhose

brainsarestillbusybuildingnewconnectionsandmaturinginotherways.The

endocannabinoidsystemisknowntoplayanimportantroleintheproper

formationofsynapses(theconnectionsbetweenneuronsduringearlybrain

development,andasimilarrolehasbeenproposedfortherefinementofneural

connectionsduringadolescence.Ifthelong-termeffectsofmarijuanauseon

cognitivefunctioningorIQareupheldbyfutureresearch,thismaybeone

avenuebywhichmarijuanauseduringadolescenceproducesitslong-term

effects.44

However,recentresultsfromtwoprospectivelongitudinaltwinstudiesdidnot

supportacausalrelationshipbetweenmarijuanauseandIQloss.Thosewho

usedmarijuanadidshowasignificantdeclineinverbalability(equivalentto4

IQpointsandingeneralknowledgebetweenthepreteenyears(ages9to12,

beforeuseandlateadolescence/earlyadulthood(ages17to20.However,at

thestartofthestudy,thosewhowoulduseinthefuturealreadyhadlower

scoresonthesemeasuresthanthosewhowouldnotuseinthefuture,andno

predictabledifferencewasfoundbetweentwinswhenoneusedmarijuanaand

onedidnot.ThissuggeststhatobservedIQdeclines,atleastacross

adolescence,maybecausedbysharedfamilialfactors(e.g.,genetics,family

environment,notbymarijuanauseitself.45Itshouldbenoted,though,that

thesestudieswereshorterindurationthantheNewZealandstudyanddidnot

exploretheimpactofthedoseofmarijuana(i.e.,heavyuseorthedevelopment

ofacannabisusedisorder;thismayhavemaskedadose-ordiagnosis-

dependenteffect.

Theabilitytodrawdefinitiveconclusionsaboutmarijuana’slong-termimpacton

thehumanbrainfrompaststudiesisoftenlimitedbythefactthatstudy

participantsusemultiplesubstances,andthereisoftenlimiteddataaboutthe

participants’healthormentalfunctioningpriortothestudy.Overthenext

decade,theNationalInstitutesofHealthisfundingtheAdolescentBrain

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CognitiveDevelopment(ABCDstudy—amajorlongitudinalstudythatwilltrack

alargesampleofyoungAmericansfromlatechildhood(beforefirstuseof

drugstoearlyadulthood.Thestudywilluseneuroimagingandotheradvanced

toolstoclarifypreciselyhowandtowhatextentmarijuanaandother

substances,aloneandincombination,affectadolescentbraindevelopment.

Marijuana,Memory,andtheHippocampus

Distributionofcannabinoidreceptorsintheratbrain.Brainimagerevealshigh

levels(showninorangeandyellow)ofcannabinoidreceptorsinmanyareas,

includingthecortex,hippocampus,cerebellum,andnucleusaccumbens

(ventralstriatum).

MemoryimpairmentfrommarijuanauseoccursbecauseTHCaltershowthe

hippocampus,abrainarearesponsibleformemoryformation,processes

information.Mostoftheevidencesupportingthisassertioncomesfromanimal

studies.Forexample,ratsexposedtoTHCinutero,soonafterbirth,orduring

adolescence,shownotableproblemswithspecificlearning/memorytaskslater

inlife.Moreover,cognitiveimpairmentinadultratsisassociatedwithstructural

andfunctionalchangesinthehippocampusfromTHCexposureduring

adolescence.

ImagebytheNIDA

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Aspeopleage,theyloseneuronsinthehippocampus,whichdecreasestheir

abilitytolearnnewinformation.ChronicTHCexposuremayhastenage-related

lossofhippocampalneurons.Inonestudy,ratsexposedtoTHCeverydayfor8

months(approximately30percentoftheirlifespan)showedalevelofnervecell

lossat11to12monthsofagethatequaledthatofunexposedanimalstwice

theirage.

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Ismarijuanaagatewaydrug?

Someresearchsuggeststhatmarijuanauseislikelytoprecedeuseofotherlicit

earlyinlife.�ItisalsoconsistentwithanimalexperimentsshowingTHC’s

drugs�andare,likemarijuana,alsotypicallyusedbeforeapersonprogressesto

other,moreharmfulsubstances.

Itisimportanttonotethatotherfactorsbesidesbiologicalmechanisms,suchasa

person’ssocialenvironment,arealsocriticalinaperson’sriskfordruguse.An

alternativetothegateway-drughypothesisisthatpeoplewhoaremore

vulnerabletodrug-takingaresimplymorelikelytostartwithreadilyavailable

substancessuchasmarijuana,tobacco,oralcohol,andtheirsubsequentsocial

andillicitsubstance�andthedevelopmentofaddictiontoothersubstances.For

instance,astudyusinglongitudinaldatafromtheNationalEpidemiologicalStudy

ofAlcoholUseandRelatedDisordersfoundthatadultswhoreportedmarijuana

useduringthefirstwaveofthesurveyweremorelikelythanadultswhodidnot

usemarijuanatodevelopanalcoholusedisorderwithin3years;peoplewho

usedmarijuanaandalreadyhadanalcoholusedisorderattheoutsetwereat

greaterriskoftheiralcoholusedisorderworsening.Marijuanauseisalsolinked

toothersubstanceusedisordersincludingnicotineaddiction.

Earlyexposuretocannabinoidsinadolescentrodentsdecreasesthereactivityof

braindopaminerewardcenterslaterinadulthood.Totheextentthatthese

findingsgeneralizetohumans,thiscouldhelpexplaintheincreased

vulnerabilityforaddictiontoothersubstancesofmisuselaterinlifethatmost

epidemiologicalstudieshavereportedforpeoplewhobeginmarijuanause

abilityto"prime"thebrainforenhancedresponsestootherdrugs.�Forexample,

ratspreviouslyadministeredTHCshowheightenedbehavioralresponsenotonly

whenfurtherexposedtoTHCbutalsowhenexposedtootherdrugssuchas

morphine—aphenomenoncalledcross-sensitization.

Thesefindingsareconsistentwiththeideaofmarijuanaasa"gatewaydrug."

However,themajorityofpeoplewhousemarijuanadonotgoontouseother,

"harder"substances.Also,cross-sensitizationisnotuniquetomarijuana.Alcohol

andnicotinealsoprimethebrainforaheightenedresponsetoother

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interactionswithotherswhousedrugsincreasestheirchancesoftryingother

drugs.Furtherresearchisneededtoexplorethisquestion.

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Howdoesmarijuanauseaffect

school,work,andsociallife?

Imageby©iStock.com/AntonioGuillem

Researchhasshownthatmarijuana’snegativeeffectsonattention,memory,

andlearningcanlastfordaysorweeksaftertheacuteeffectsofthedrugwear

off,dependingontheperson’shistorywiththedrug.Consequently,someone

whosmokesmarijuanadailymaybefunctioningatareducedintellectuallevel

mostorallofthetime.Considerableevidencesuggeststhatstudentswho

smokemarijuanahavepoorereducationaloutcomesthantheirnonsmoking

peers.Forexample,areviewof48relevantstudiesfoundmarijuanausetobe

associatedwithreducededucationalattainment(i.e.,reducedchancesof

graduating).�ArecentanalysisusingdatafromthreelargestudiesinAustraliaand

NewZealandfoundthatadolescentswhousedmarijuanaregularlywere

significantlylesslikelythantheirnon-usingpeerstofinishhighschoolorobtaina

degree.Theyalsohadamuchhigherchanceofdevelopingdependence,using

otherdrugs,andattemptingsuicide.Severalstudieshavealsolinkedheavy

marijuanausetolowerincome,greaterwelfaredependence,unemployment,

criminalbehavior,andlowerlifesatisfaction.

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notmorethan50times.�Allparticipantshadsimilareducationandincome

backgrounds,butsignificantdifferenceswerefoundintheireducational

attainment:Fewerofthosewhoengagedinheavycannabisusecompleted

college,andmorehadyearlyhouseholdincomesoflessthan$30,000.When

askedhowmarijuanaaffectedtheircognitiveabilities,careerachievements,

sociallives,andphysicalandmentalhealth,themajorityofthosewhoused

heavilyreportedthatmarijuanahadnegativeeffectsinalltheseareasoftheir

lives.

Studieshavealsosuggestedspecificlinksbetweenmarijuanauseandadverse

consequencesintheworkplace,suchasincreasedriskforinjuryor

accidents.�Onestudyamongpostalworkersfoundthatemployeeswhotested

positiveformarijuanaonapre-employmenturinedrugtesthad55percentmore

industrialaccidents,85percentmoreinjuries,and75percentgreater

absenteeismcomparedwiththosewhotestednegativeformarijuanause.

Towhatdegreemarijuanauseisdirectlycausalintheseassociationsremains

anopenquestionrequiringfurtherresearch.Itispossiblethatotherfactors

independentlypredisposepeopletobothmarijuanauseandvariousnegativelife

outcomessuchasschooldropout.Thatsaid,peoplereportaperceivedinfluence

oftheirmarijuanauseonpooroutcomesonavarietyoflifesatisfactionand

achievementmeasures.Onestudy,forexample,comparedpeopleinvolvedwith

currentandformerlong-term,heavyuseofmarijuanawithacontrolgroupwho

reportedsmokingmarijuanaatleastonceintheirlivesbut

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Istherealinkbetweenmarijuanause

andpsychiatricdisorders?

Severalstudieshavelinkedmarijuanausetoincreasedriskforpsychiatric

disorders,includingpsychosis(schizophrenia),depression,anxiety,and

substanceusedisorders,butwhetherandtowhatextentitactuallycauses

theseconditionsisnotalwayseasytodetermine.Theamountofdrugused,the

ageatfirstuse,andgeneticvulnerabilityhaveallbeenshowntoinfluencethis

relationship.Thestrongestevidencetodateconcernslinksbetweenmarijuana

useandsubstanceusedisordersandbetweenmarijuanauseandpsychiatric

disordersinthosewithapreexistinggeneticorothervulnerability.

ResearchusinglongitudinaldatafromtheNationalEpidemiologicalSurveyon

AlcoholandRelatedConditionsexaminedassociationsbetweenmarijuana

use,moodandanxietydisorders,andsubstanceusedisorders.Afteradjusting

forvariousconfoundingfactors,noassociationbetweenmarijuanauseand

moodandanxietydisorderswasfound.Theonlysignificantassociationswere

increasedriskofalcoholusedisorders,nicotinedependence,marijuanause

disorder,andotherdrugusedisorders.

Recentresearch(see"AKT1GeneVariationsandPsychosis")hasfoundthat

peoplewhousemarijuanaandcarryaspecificvariantoftheAKT1gene,which

codesforanenzymethataffectsdopaminesignalinginthestriatum,areat

increasedriskofdevelopingpsychosis.Thestriatumisanareaofthebrainthat

becomesactivatedandfloodedwithdopaminewhencertainstimuliarepresent.

Onestudyfoundthattheriskofpsychosisamongthosewiththisvariantwas

seventimeshigherforthosewhousedmarijuanadailycomparedwiththosewho

useditinfrequentlyorusednoneatall.

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Whetheradolescentmarijuanausecancontributetodevelopingpsychosislaterin

adulthoodappearstodependonwhetherapersonalreadyhasageneticallybased

vulnerabilitytothedisorder.TheAKT1genegovernsanenzymethataffectsbrain

signalinginvolvingtheneurotransmitterdopamine.Altereddopaminesignalingis

knowntobeinvolvedinschizophrenia.AKT1cantakeoneofthreeformsinaspecific

regionofthegeneimplicatedinsusceptibilitytoschizophrenia:T/T,C/T,andC/C.

Thosewhousemarijuanadaily(greenbars)withtheC/Cvarianthaveaseventimes

higherriskofdevelopingpsychosisthanthosewhouseitinfrequentlyorusenoneat

all.TheriskforpsychosisamongthosewiththeT/Tvariantwasunaffectedby

whethertheyusedmarijuana.

Source:DiFortietal.BiolPsychiatry.2012.

Anotherstudyfoundanincreasedriskofpsychosisamongadultswhohadused

marijuanainadolescenceandalsocarriedaspecificvariantofthegenefor

catechol-O-methyltransferase (COMT),anenzymethatdegrades

neurotransmitterssuchasdopamineandnorepinephrine(see"GeneticVariations

inCOMTInfluencestheHarmfulEffectsofAbusedDrugs").Marijuanausehas

alsobeenshowntoworsenthecourseofillnessinpatientswhoalreadyhave

schizophrenia.Asmentionedpreviously,marijuanacanproduceanacute

psychoticreactioninnon-schizophrenicpeoplewhousemarijuana,especiallyat

highdoses,althoughthisfadesasthedrugwearsoff.

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Theinfluenceofadolescentmarijuanauseonadultpsychosisisaffectedbygenetic

variables.Thisfigureshowsthatvariationsinagenecanaffectthelikelihoodof

developingpsychosisinadulthoodfollowingexposuretocannabisinadolescence.

TheCOMTgenegovernsanenzymethatbreaksdowndopamine,abrainchemical

involvedinschizophrenia.Itcomesintwoforms:"Met"and"Val."Individualswithone

ortwocopiesoftheValvarianthaveahigherriskofdevelopingschizophrenic-type

disordersiftheyusedcannabisduringadolescence(darkbars).Thosewithonlythe

Metvariantwereunaffectedbycannabisuse.

Source:Caspietal.BiolPsychiatry.2005.

Inconsistentandmodestassociationshavebeenreportedbetweenmarijuanause

andsuicidalthoughtsandattemptedsuicideamongteens.Marijuanahasalso

beenassociatedwithanamotivationalsyndrome,definedasadiminishedor

absentdrivetoengageintypicallyrewardingactivities.Becauseoftheroleofthe

endocannabinoidsysteminregulatingmoodandreward,ithasbeen

hypothesizedthatbrainchangesresultingfromearlyuseofmarijuanamay

underlietheseassociations,butmoreresearchisneededtoverifythatsuchlinks

existandbetterunderstandthem.

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AdverseConsequencesofMarijuanaUse

Acute(presentduringintoxication)

Impairedshort-termmemory

Impairedattention,judgment,andothercognitivefunctions

Impairedcoordinationandbalance

Increasedheartrate

Anxiety,paranoia

Psychosis(uncommon)

Persistent(lastinglongerthanintoxication,butmaynotbe

permanent)

Impairedlearningandcoordination

Photoby©getttyimages.com/Fuse

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Sleepproblems

Long-term(cumulativeeffectsofrepeateduse)

Potentialformarijuanaaddiction

ImpairmentsinlearningandmemorywithpotentiallossofIQ*

Increasedriskofchroniccough,bronchitis

Increasedriskofotherdrugandalcoholusedisorders

Increasedriskofschizophreniainpeoplewithgeneticvulnerability**

*LossofIQamongindividualswithpersistentmarijuanausedisorderwho

beganusingheavilyduringadolescence

**Theseareoftenreportedco-occurringsymptoms/disorderswithchronic

marijuanause.However,researchhasnotyetdeterminedwhether

marijuanaiscausalorjustassociatedwiththesementalproblems.

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Whataremarijuana'seffectsonlung

health?

Onestudyfoundthatpeoplewhofrequentlysmokemarijuanahad

moreoutpatientmedicalvisitsforrespiratoryproblemsthanthosewhodonot

includingpneumonia. Animalandhumanstudieshavenotfoundthat

Liketobaccosmoke,marijuanasmokeisanirritanttothethroatandlungsand

cancauseaheavycoughduringuse.Italsocontainslevelsofvolatile

chemicalsandtarthataresimilartotobaccosmoke,raisingconcernsaboutrisk

forcancerandlungdisease.

Marijuanasmokingisassociatedwithlargeairwayinflammation,increased

airwayresistance,andlunghyperinflation,andthosewhosmokemarijuana

regularlyreportmoresymptomsofchronicbronchitisthanthosewhodonot

smoke.

smoke.�Somecasestudieshavesuggestedthat,becauseofTHC’simmune-

suppressingeffects,smokingmarijuanamightincreasesusceptibilitytolung

infections,suchaspneumonia,inpeoplewithimmunedeficiencies;however,a

largeAIDScohortstudydidnotconfirmsuchanassociation.�Smokingmarijuana

mayalsoreducetherespiratorysystem’simmuneresponse,increasingthe

likelihoodofthepersonacquiringrespiratoryinfections,

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marijuanaincreasesriskforemphysema.

Whethersmokingmarijuanacauseslungcancer,ascigarettesmokingdoes,

remainsanopenquestion.Marijuanasmokecontainscarcinogeniccombustion

products,includingabout50percentmorebenzopreneand75percentmore

benzanthracene(andmorephenols,vinylchlorides,nitrosamines,reactive

oxygenspecies)thancigarettesmoke.Becauseofhowitistypicallysmoked

(deeperinhale,heldforlonger),marijuanasmokingleadstofourtimesthe

depositionoftarcomparedtocigarettesmoking.�However,whileafewsmall,

uncontrolledstudieshavesuggestedthatheavy,regularmarijuanasmokingcould

increaseriskforrespiratorycancers,well-designedpopulationstudieshavefailed

tofindanincreasedriskoflungcancerassociatedwithmarijuanause.

Onecomplexityincomparingthelung-healthrisksofmarijuanaandtobacco

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concernstheverydifferentwaysthetwosubstancesareused.Whilepeople

whosmokemarijuanaofteninhalemoredeeplyandholdthesmokeintheir

lungsforalongerdurationthanistypicalwithcigarettes,marijuana’seffectslast

longer,sopeoplewhousemarijuanamaysmokelessfrequentlythanthose

whosmokecigarettes.

Additionally,thefactthatmanypeopleusebothmarijuanaandtobaccomakes

determiningmarijuana’sprecisecontributiontolungcancerrisk,ifany,difficult

toestablish.CellcultureandanimalstudieshavealsosuggestedTHCand

CBDmayhaveantitumoreffects,andthishasbeenproposedasonereason

whystrongerexpectedassociationsarenotseenbetweenmarijuanauseand

lungcancer,butmoreresearchisneededonthisquestion.

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Whataremarijuana’seffectsonother

aspectsofphysicalhealth?

oxygen.�Marijuanamayalsocauseorthostatichypotension(headrushor

dizzinessonstandingup),possiblyraisingdangerfromfaintingandfalls.

Tolerancetosomecardiovasculareffectsoftendevelopswithrepeated

Withinafewminutesafterinhalingmarijuanasmoke,aperson’sheartrate

speedsup,thebreathingpassagesrelaxandbecomeenlarged,andblood

vesselsintheeyesexpand,makingtheeyeslookbloodshot.Theheartrate—

normally70to80beatsperminute—mayincreaseby20to50beatsperminute

ormayevendoubleinsomecases.Takingotherdrugswithmarijuanacan

amplifythiseffect.

Limitedevidencesuggeststhataperson’sriskofheartattackduringthefirsthour

aftersmokingmarijuanaisnearlyfivetimeshisorherusualrisk.Thisobservation

couldbepartlyexplainedbymarijuanaraisingbloodpressure(insomecases)

andheartrateandreducingtheblood’scapacitytocarry

exposure.�Thesehealtheffectsneedtobeexaminedmoreclosely,particularly

giventheincreasinguseof"medicalmarijuana"bypeoplewithhealthissuesand

olderadultswhomayhaveincreasedbaselinevulnerabilityduetoage-related

cardiovascularriskfactors(see"Ismarijuanasafeandeffectiveasmedicine?").

Afewstudieshaveshownaclearlinkbetweenmarijuanauseinadolescenceand

increasedriskforanaggressiveformoftesticularcancer

(nonseminomatoustesticulargermcelltumor)thatpredominantlystrikesyoung

adultmales.�Theearlyonsetoftesticularcancerscomparedtolungandmost

othercancersindicatesthat,whateverthenatureofmarijuana’scontribution,it

mayaccumulateoverjustafewyearsofuse.

Studieshaveshownthatinrarecases,chronicuseofmarijuanacanleadto

CannabinoidHyperemesisSyndrome—aconditionmarkedbyrecurrentboutsof

severenausea,vomiting,anddehydration.Thissyndromehasbeenfoundto

occurinpersonsunder50yearsofageandwithalonghistoryofmarijuanause.

CannabinoidHyperemesisSyndromecanleadsuffererstomakefrequent

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tripstotheemergencyroom,butmayberesolvedwhenapersonstopsusing

marijuana.

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Ismarijuanasafeandeffectiveas

medicine?

Thepotentialmedicinalpropertiesofmarijuanaanditscomponentshavebeen

thesubjectofresearchandheateddebatefordecades.THCitselfhasproven

medicalbenefitsinparticularformulations.TheU.S.FoodandDrug

AdministrationhasapprovedTHC-basedmedications,dronabinol(Marinol )

andnabilone(Cesamet ),prescribedinpillformforthetreatmentofnauseain

patientsundergoingcancerchemotherapyandtostimulateappetiteinpatients

withwastingsyndromeduetoAIDS.

Inaddition,severalothermarijuana-basedmedicationshavebeenapprovedor

areundergoingclinicaltrials.Nabiximols(Sativex ),amouthspraythatis

currentlyavailableintheUnitedKingdom,Canada,andseveralEuropean

countriesfortreatingthespasticityandneuropathicpainthatmayaccompany

multiplesclerosis,combinesTHCwithanotherchemicalfoundinmarijuana

calledcannabidiol(CBD).CBDdoesnothavetherewardingpropertiesofTHC,

andanecdotalreportsindicateitmayhavepromiseforthetreatmentofseizure

disorders,amongotherconditions.ACBD-basedliquidmedicationcalled

EpidiolexiscurrentlybeingtestedintheUnitedStatesforthetreatmentoftwo

formsofseverechildhoodepilepsy,DravetsyndromeandLennox-Gastaut

syndrome.

Researchersgenerallyconsidermedicationslikethese,whichusepurified

chemicalsderivedfromorbasedonthoseinthemarijuanaplant,tobemore

promisingtherapeuticallythanuseofthewholemarijuanaplantoritscrude

extracts.Developmentofdrugsfrombotanicalssuchasthemarijuanaplant

posesnumerouschallenges.Botanicalsmaycontainhundredsofunknown,

activechemicals,anditcanbedifficulttodevelopaproductwithaccurateand

consistentdosesofthesechemicals.Useofmarijuanaasmedicinealsoposes

otherproblemssuchastheadversehealtheffectsofsmokingandTHC-induced

cognitiveimpairment.Nevertheless,agrowingnumberofstateshavelegalized

dispensingofmarijuanaoritsextractstopeoplewitharangeofmedical

conditions.

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Anadditionalconcernwith"medicalmarijuana"isthatlittleisknownaboutthe

long-termimpactofitsusebypeoplewithhealth-and/orage-related

vulnerabilities—suchasolderadultsorpeoplewithcancer,AIDS,

cardiovasculardisease,multiplesclerosis,orotherneurodegenerative

diseases.Furtherresearchwillbeneededtodeterminewhetherpeoplewhose

healthhasbeencompromisedbydiseaseoritstreatment(e.g.,chemotherapy)

areatgreaterriskforadversehealthoutcomesfrommarijuanause.

MedicalMarijuanaLegalizationandPrescriptionOpioid

UseOutcomes

NIDAfundedtworecentstudiesthatexploredtherelationshipbetween

marijuanalegalizationandadverseoutcomesassociatedwithprescription

opioids.Thefirstfoundanassociationbetweenmedicalmarijuana

legalizationandareductioninoverdosedeathsfromopioidpainrelievers,

aneffectthatstrengthenedineachyearfollowingtheimplementationof

legislation.�Thepopulation-basednatureofthisstudydoesnotestablisha

causalrelationshiporgiveevidenceforchangesinpainpatientbehavior.

ThesecondNIDA-fundedstudy,amoredetailedanalysisbytheRAND

Corporation,showedthatlegallyprotectedaccesstomedicalmarijuana

dispensariesisassociatedwithlowerlevelsofopioidprescribing,lowerself-

reportofnonmedicalprescriptionopioiduse,lowertreatmentadmissionsfor

prescriptionopioidusedisorders,andreductioninprescriptionopioid

overdosedeaths.Notably,thereductionindeathswaspresentonlyin

stateswithdispensaries(notjustmedicalmarijuanalaws)andwasgreater

instateswithactivedispensaries.

Researchintotheeffectsofcannabisonopioiduseinpainpatientsis

limited,butdatasuggestthatmedicalcannabistreatmentmayreducethe

doseofopioidsrequiredforpainrelief.�*nadditiontoitsresearchportfolio

ontherolesofthecannabinoidandopioidsystemsinpain,NIDAisfunding

additionalstudiesthatwillprovidedatarelatingtomedicalmarijuanaand

opioids:

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effectsofaccesstomedicalmarijuanaonsubstanceuse,including

nonmedicaluseofprescriptionopioids(projectnumbers

DA031816-05,DA039293-01A1,DA037341-02,DA032693-04)

mentalandphysicalfunctioningofacohortofpainpatientsseeking

medicalmarijuanatreatment(DA033397-03)

theimpactofmedicalmarijuanapoliciesonhealthoutcomes

(DA034067-03)

AnotherrecentstudyanalyzedMedicareprescriptiondrugcoveragedata

andfoundthatavailabilityofmedicalmarijuanasignificantlyreduced

prescribingofmedicationsusedforconditionsthatmedicalmarijuanacan

treat,includingopioidsforpain.�Overallsavingsforallprescriptiondrugs

wereestimatedtobe$165.2millionin2013.

Thoughnoneofthesestudiesaredefinitive,theycumulativelysuggestthat

medicalmarijuanaproductsmayhavearoleinreducingtheuseofopioids

neededtocontrolpain.Moreresearchisneededtoinvestigatethis

possibility.

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Whataretheeffectsofsecondhand

exposuretomarijuanasmoke?

longer.�Oneminuteofexposuretosecondhandmarijuanasmokeimpairedflow-

mediateddilation(theextenttowhicharteriesenlargeinresponsetoincreased

bloodflow)ofthefemoralarterythatlastedforatleast90minutes;impairment

from1minuteofsecondhandtobaccoexposurewasrecoveredwithin30

minutes.TheeffectsofmarijuanasmokewereindependentofTHC

concentration;i.e.,whenTHCwasremoved,theimpairmentwasstillpresent.

Thisresearchhasnotyetbeenconductedwithhumansubjects,butthetoxins

andtarlevelsknowntobepresentinmarijuanasmoke(see“Whatare

marijuana’seffectsonlunghealth?”)raiseconcernsaboutexposureamong

vulnerablepopulations,suchaschildrenandpeoplewithasthma.

Peopleoftenaskaboutthepossiblepsychoactiveeffectofexposureto

secondhandmarijuanasmokeandwhetherapersonwhohasinhaled

secondhandmarijuanasmokecouldfailadrugtest.Researchersmeasuredthe

amountofTHCinthebloodofpeoplewhodonotsmokemarijuanaandhad

spent3hoursinawell-ventilatedspacewithpeoplecasuallysmoking

marijuana;THCwaspresentinthebloodofthenonsmokingparticipants,but

theamountwaswellbelowthelevelneededtofailadrugtest.Anotherstudy

thatvariedthelevelsofventilationandthepotencyofthemarijuanafoundthat

somenonsmokingparticipantsexposedforanhourtohigh-THCmarijuana

(11.3percentTHCconcentration)inanunventilatedroomshowedpositiveurine

assaysinthehoursdirectlyfollowingexposure;afollow-upstudyshowedthat

nonsmokingpeopleinaconfinedspacewithpeoplesmokinghigh-THC

marijuanareportedmildsubjectiveeffectsofthedrug—a"contacthigh"—and

displayedmildimpairmentsonperformanceinmotortasks.

Theknownhealthrisksofsecondhandexposuretocigarettesmoke—tothe

heartorlungs,forinstance—raisequestionsaboutwhethersecondhand

exposuretomarijuanasmokeposessimilarhealthrisks.Atthispoint,verylittle

researchonthisquestionhasbeenconducted.A2016studyinratsfoundthat

secondhandexposuretomarijuanasmokeaffectedameasureofbloodvessel

functionasmuchassecondhandtobaccosmoke,andtheeffectslasted

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Canmarijuanauseduringandafter

pregnancyharmthebaby?

Moreresearchisneededonhowmarijuanauseduringpregnancycouldimpact

thehealthanddevelopmentofinfants,givenchangingpoliciesaboutaccessto

marijuana,aswellassignificantincreasesoverthelastdecadeinthenumber

ofpregnantwomenseekingsubstanceusedisordertreatmentformarijuana

althoughanimalstudiesindicatethattheriskformiscarriage

Photoby©Thinkstock.com/CreatasImages

use.�Onestudyfoundthatabout20%ofpregnantwomen24-years-oldand

youngerscreenedpositiveformarijuana.However,thisstudyalsofoundthat

womenwereabouttwiceaslikelytoscreenpositiveformarijuanauseviaa

drugtestthantheystateinself-reportedmeasures.Thissuggeststhatself-

reportedratesofmarijuanauseinpregnantfemalesmaynotbeanaccurate

measureofmarijuanause.

Thereisnohumanresearchconnectingmarijuanausetothechanceof

miscarriage,

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risks.�Researchhasshownthatpregnantwomenwhousemarijuanahavea

increasesifmarijuanaisusedearlyinpregnancy.�Someassociationshave

beenfoundbetweenmarijuanauseduringpregnancyandfuturedevelopmental

andhyperactivitydisordersinchildren.Evidenceismixedastowhether

marijuanausebypregnantwomenisassociatedwithlowbirth

rate�orprematurebirth,althoughlong-termusemayelevatethese

2.3timesgreaterriskofstillbirth.�Giventhepotentialofmarijuanatonegatively

impactthedevelopingbrain,theAmericanCollegeofObstetriciansand

Gynecologistsrecommendsthatobstetrician-gynecologistscounselwomen

againstusingmarijuanawhiletryingtogetpregnant,duringpregnancy,andwhile

theyarebreastfeeding.

RecentTrendsinTreatmentAdmissionsforMarijuanaUseDuringPregnancy

Source:Martinetal.,2015

Somewomenreportusingmarijuanatotreatseverenauseaassociatedwiththeir

pregnancy;�however,thereisnoresearchconfirmingthatthisisasafepractice,

anditisgenerallynotrecommended.Womenconsideringusingmedical

marijuanawhilepregnantshouldnotdosowithoutcheckingwiththeirhealthcare

providers.Animalstudieshaveshownthatmoderateconcentrations

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ofTHC,whenadministeredtomotherswhilepregnantornursing,couldhave

long-lastingeffectsonthechild,includingincreasingstressresponsivityand

abnormalpatternsofsocialinteractions.�Animalstudiesalsoshowlearning

deficitsinprenatallyexposedindividuals.

Humanresearchhasshownthatsomebabiesborntowomenwhoused

marijuanaduringtheirpregnanciesdisplayalteredresponsestovisualstimuli,

increasedtrembling,andahigh-pitchedcry,�whichcouldindicateproblems

withneurologicaldevelopment.�Inschool,marijuana-exposedchildrenare

morelikelytoshowgapsinproblem-solvingskills,memory,andtheabilityto

MoreinformationonmarijuanauseduringpregnancycanbefoundintheNIDA's

SubstanceUseinWomenResearchReport.

Verylittleisknownaboutmarijuanauseandbreastfeeding.Onestudysuggests

thatmoderateamountsofTHCfindtheirwayintobreastmilkwhenanursing

mother uses marijuana�� Some evidence shows that exposure to THC through

breastmilkinthefirstmonthoflifecouldresultindecreasedmotordevelopment

remainattentive.�Moreresearchisneeded,however,todisentanglemarijuana-

specificeffectsfromthoseofotherenvironmentalfactorsthatcouldbeassociated

withamother'smarijuanause,suchasanimpoverishedhomeenvironmentorthe

mother'suseofotherdrugs.�Prenatalmarijuanaexposureisalsoassociatedwith

anincreasedlikelihoodofapersonusingmarijuanaasayoungadult,evenwhen

otherfactorsthatinfluencedruguseare�DPOTJEFSFE�

at1yearofage.�TherehavebeennostudiestodetermineifexposuretoTHC

duringnursingislinkedtoeffectslaterinthechild'slife.Withregularuse,THC

canaccumulateinhumanbreastmilktohighconcentrations.Becauseababy's

brainisstillforming,THCconsumedinbreastmilkcouldaffectbraindevelopment.

Givenalltheseuncertainties,nursingmothersarediscouragedfromusing

marijuana.�Newmothersusingmedicalmarijuanashouldbevigilantabout

coordinatingcarebetweenthedoctorrecommendingtheirmarijuanauseandthe

pediatriciancaringfortheirbaby.

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AvailableTreatmentsforMarijuana

UseDisorders

Marijuanausedisordersappeartobeverysimilartoothersubstanceuse

disorders,althoughthelong-termclinicaloutcomesmaybelesssevere.On

average,adultsseekingtreatmentformarijuanausedisordershaveused

marijuananearlyeverydayformorethan10yearsandhaveattemptedtoquit

morethansixtimes.�Peoplewithmarijuanausedisorders,especially

adolescents,oftenalsosufferfromotherpsychiatricdisorders

(comorbidity).�Theymayalsouseorbeaddictedtoothersubstances,suchas

cocaineoralcohol.Availablestudiesindicatethateffectivelytreatingthemental

healthdisorderwithstandardtreatmentsinvolvingmedicationsandbehavioral

therapiesmayhelpreducemarijuanause,particularlyamongthoseinvolvedwith

heavyuseandthosewithmorechronicmentaldisorders.Thefollowing

behavioraltreatmentshaveshownpromise:

Cognitive-behavioraltherapy:Aformofpsychotherapythatteachespeople

strategiestoidentifyandcorrectproblematicbehaviorsinordertoenhance

self-control,stopdruguse,andaddressarangeofotherproblemsthatoften

co-occurwiththem.

Contingencymanagement:Atherapeuticmanagementapproachbasedon

frequentmonitoringofthetargetbehaviorandtheprovision(orremoval)of

tangible,positiverewardswhenthetargetbehavioroccurs(ordoesnot).

Motivationalenhancementtherapy:Asystematicformofintervention

designedtoproducerapid,internallymotivatedchange;thetherapydoes

notattempttotreattheperson,butrathermobilizehisorherowninternal

resourcesforchangeandengagementintreatment.

Currently,theFDAhasnotapprovedanymedicationsforthetreatmentof

marijuanausedisorder,butresearchisactiveinthisarea.Becausesleep

problemsfeatureprominentlyinmarijuanawithdrawal,somestudiesare

examiningtheeffectivenessofmedicationsthataidinsleep.Medicationsthat

haveshownpromiseinearlystudiesorsmallclinicaltrialsincludethesleepaid

zolpidem(Ambien ),ananti-anxiety/anti-stressmedicationcalledbuspirone®

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(BuSpar ),andananti-epilepticdrugcalledgabapentin

(Horizant ,Neurontin )thatmayimprovesleepand,possibly,executive

function.OtheragentsbeingstudiedincludethenutritionalsupplementN-

acetylcysteineandchemicalscalledFAAHinhibitors,whichmayreduce

withdrawalbyinhibitingthebreakdownofthebody’sowncannabinoids.Future

directionsincludethestudyofsubstancescalledallostericmodulatorsthat

interactwithcannabinoidreceptorstoinhibitTHC’srewardingeffects.

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“This course was developed from the public domain document: Marijuana – National Institute on Drug

Abuse; National Institutes of Health; U.S. Department of Health and Human Services (2018)”