People with a substance use disorder may have distorted thinking and behaviors. Changes in the brain's structure and function are what cause people to have ...AsdescribedinthePrivacyPolicyoftheAmericanPsychiatricAssociation(APA),thiswebsite&applicationutilizecookies.Byclosingthismessage,continuingthenavigationorotherwisecontinuingtoviewtheAPA'swebsites&applications,youconfirmthatyouunderstandandacceptthetermsoftheAPA'sPrivacyPolicy,includingtheuseofcookies.ReadOurPrivacyPolicyIagreePatients&FamiliesAddictionandSubstanceUseDisordersPatients&FamiliesWhatIsPsychiatry?FindaPsychiatristAddictionandSubstanceUseDisordersOpioidUseDisorderAnxietyDisordersDepressionDissociativeDisordersEatingDisordersGenderDysphoriaObsessive-CompulsiveDisorder(OCD)PersonalityDisordersPosttraumaticStressDisorder(PTSD)SchizophreniaViewMoreTopics»BacktoAddictionandSubstanceUseDisordersAddictionandSubstanceUseDisordersWhatIsaSubstanceUseDisorder?Substanceusedisorder(SUD)iscomplexaconditioninwhichthereisuncontrolleduseofasubstancedespiteharmfulconsequence.PeoplewithSUDhaveanintensefocusonusingacertainsubstance(s)suchasalcohol,tobacco,orillicitdrugs,tothepointwheretheperson’sabilitytofunctionindaytodaylifebecomesimpaired.Peoplekeepusingthesubstanceevenwhentheyknowitiscausingorwillcauseproblems.ThemostsevereSUDsaresometimescalledaddictions.Peoplecandevelopanaddictionto:AlcoholMarijuanaPCP,LSDandotherhallucinogensInhalants,suchas,paintthinnersandglueOpioidpainkillers,suchascodeineandoxycodone,heroinSedatives,hypnoticsandanxiolytics(medicinesforanxietysuchastranquilizers)Cocaine,methamphetamineandotherstimulantsTobaccoPeoplewithasubstanceusedisordermayhavedistortedthinkingandbehaviors.Changesinthebrain’sstructureandfunctionarewhatcausepeopletohaveintensecravings,changesinpersonality,abnormalmovements,andotherbehaviors.Brainimagingstudiesshowchangesintheareasofthebrainthatrelatetojudgment,decisionmaking,learning,memory,andbehavioralcontrol.Repeatedsubstanceusecancausechangesinhowthebrainfunctions.These