1 2934 123 GENETIC ADDICTION RISK SCORE (GARS) , A PREDICTOR OF VULNERABILITY TO OPIOID DEPENDENCE. THE INTERACTION OF NEUROTRANSMITTERS AND GENES THAT CONTROL THE RELEASE OF DOPAMINE IS THE BRAIN REWARD CASCADE (BRC). VARIATIONS WITHIN THE BRC, WHETHER GENETIC OR EPIGENETIC, MAY PREDISPOSE INDIVIDUALS TO ADDICTIVE BEHAVIORS AND ALTERED PAIN TOLERANCE. THIS DISCUSSION AUTHORED BY A GROUP OF CONCERNED SCIENTISTS AND CLINICIANS EXAMINES THE GENETIC ADDICTION RISK SCORE (GARS), THE FIRST TEST TO ACCURATELY PREDICT VULNERABILITY TO PAIN, ADDICTION, AND OTHER COMPULSIVE BEHAVIORS, DEFINED AS REWARD DEFICIENCY SYNDROME (RDS). INNOVATIVE STRATEGIES TO COMBAT EPIDEMIC OPIOID, IATROGENIC PRESCRIPTION DRUG ABUSE AND DEATH, BASED ON THE ROLE OF DOPAMINERGIC TONE IN PAIN PATHWAYS, ARE PROPOSED. SENSITIVITY TO PAIN MAY RESIDE IN THE MESOLIMBIC PROJECTION SYSTEM, WHERE GENETIC POLYMORPHISMS ASSOCIATE WITH A PREDISPOSITION TO PAIN VULNERABILITY OR TOLERANCE. THEY PROVIDE UNIQUE THERAPEUTIC TARGETS THAT COULD ASSIST IN THE TREATMENT OF PAIN, AND IDENTIFY RISK FOR SUBSEQUENT ADDICTION. PHARMACOGENOMIC TESTING OF CANDIDATE GENES LIKE CB1, MU RECEPTORS, AND PENK MIGHT RESULT IN PHARMACOGENOMIC, PERSONALIZED SOLUTIONS, AND IMPROVED CLINICAL OUTCOMES. GENETICALLY IDENTIFYING RISK FOR ALL RDS BEHAVIORS, ESPECIALLY IN COMPROMISED POPULATIONS, MAY BE A FRONTLINE TOOL TO ASSIST MUNICIPALITIES TO PROVIDE BETTER RESOURCE ALLOCATION. 2018 2 4440 50 MOLECULAR GENETIC TESTING IN PAIN AND ADDICTION: FACTS, FICTION AND CLINICAL UTILITY. THE BRAIN REWARD CASCADE (BRC) IS AN INTERACTION OF NEUROTRANSMITTERS AND THEIR RESPECTIVE GENES TO CONTROL THE AMOUNT OF DOPAMINE RELEASED WITHIN THE BRAIN. ANY VARIATIONS WITHIN THIS PATHWAY, WHETHER GENETIC OR ENVIRONMENTAL (EPIGENETIC), MAY RESULT IN ADDICTIVE BEHAVIORS AS WELL AS ALTERED PAIN TOLERANCE. WHILE THERE ARE MANY STUDIES CLAIMING A GENETIC ASSOCIATION WITH ADDICTION AND OTHER BEHAVIORAL INFRACTIONS, DEFINED AS REWARD DEFICIENCY SYNDROME (RDS), NOT ALL ARE SCIENTIFICALLY ACCURATE AND IN SOME CASE JUST WRONG. ALBEIT OUR BIAS, WE DISCUSS HEREIN THE FACTS AND FICTIONS BEHIND MOLECULAR GENETIC TESTING IN RDS (INCLUDING PAIN AND ADDICTION) AND THE SIGNIFICANCE BEHIND THE DEVELOPMENT OF THE GENETIC ADDICTION RISK SCORE (GARSPREDX), THE FIRST TEST TO ACCURATELY PREDICT ONE'S GENETIC RISK FOR RDS. 2015 3 1984 26 EPIGENETIC ALTERATIONS IN PRESCRIPTION OPIOID MISUSE: NEW STRATEGIES FOR PRECISION PAIN MANAGEMENT. PRESCRIPTION OPIOIDS ARE USED FOR SOME CHRONIC PAIN CONDITIONS. HOWEVER, GENERALLY, LONG-TERM THERAPY HAS UNWANTED SIDE EFFECTS WHICH MAY TRIGGER ADDICTION, OVERDOSE, AND EVENTUALLY CAUSE DEATHS. OPIOID ADDICTION AND CHRONIC PAIN CONDITIONS HAVE BOTH BEEN ASSOCIATED WITH EVIDENCE OF GENETIC AND EPIGENETIC ALTERATIONS. DESPITE INTENSE RESEARCH INTEREST, MANY QUESTIONS ABOUT THE CONTRIBUTION OF EPIGENETIC CHANGES TO THIS TYPOLOGY OF ADDICTION VULNERABILITY AND DEVELOPMENT REMAIN UNANSWERED. THE AIM OF THIS REVIEW WAS TO SUMMARIZE THE EPIGENETIC MODIFICATIONS DETECTED IN SPECIFIC TISSUES OR BRAIN AREAS AND ASSOCIATED WITH OPIOID PRESCRIPTION AND MISUSE IN PATIENTS WHO HAVE INITIATED PRESCRIBED OPIOID MANAGEMENT FOR CHRONIC NON-CANCER PAIN. THE REVIEW CONSIDERS THE EFFECTS OF OPIOID EXPOSURE ON THE EPIGENOME IN CENTRAL AND PERIPHERAL TISSUES IN ANIMAL MODELS AND HUMAN SUBJECTS AND HIGHLIGHTS THE MECHANISMS IN WHICH OPIOID EPIGENETICS MAY BE INVOLVED. THIS WILL IMPROVE OUR CURRENT UNDERSTANDING, PROVIDE THE BASIS FOR TARGETED, PERSONALIZED PAIN MANAGEMENT, AND THUS BALANCE OPIOID RISKS AND BENEFITS IN MANAGING CHRONIC PAIN. 2021 4 4631 42 NEUROGENETICS OF ACUTE AND CHRONIC OPIATE/OPIOID ABSTINENCE: TREATING SYMPTOMS AND THE CAUSE. THIS REVIEW BEGINS WITH A COMPREHENSIVE HISTORY OF OPIOID DEPENDENCE AND TREATMENT IN THE UNITED STATES. THE FOCUS IS AN EVIDENCE-BASED TREATMENT MODEL FOR OPIOID/OPIATE DEPENDENT INDIVIDUALS. THE ROLE OF REWARD GENETIC POLYMORPHISMS AND THE EPIGENETIC MODIFICATIONS THAT LEAD TO VULNERABILITY TO USE AND MISUSE OF OPIATES/OPIOID TO TREAT PAIN ARE REVIEWED. THE NEUROCHEMICAL MECHANISMS OF ACUTE OPIATE WITHDRAWAL AND OPIATE/OPIOID REWARD MECHANISMS ARE EXPLORED WITH A GOAL OF IDENTIFYING SPECIFIC TREATMENT TARGETS. ALTERATIONS IN FUNCTIONAL BRAIN CONNECTIVITY BASED ON NEUROBIOLOGICAL MECHANISMS IN HEROIN DEPENDENCE AND ABSTINENCE ARE ALSO REVIEWED. A NEW CLINICAL MODEL AN ALTERNATIVE TO MERELY BLOCKING ACUTE WITHDRAWAL SYMPTOMS AS IDENTIFIED IN THE DSM -5 IS PROPOSED. GENETIC DIAGNOSIS AT THE ONSET OF DETOXIFICATION, TO DETERMINE RISK STRATIFICATION, AND IDENTIFY POLYMORPHIC GENE TARGETS FOR PHARMACEUTICAL AND NUTRACEUTICAL INTERVENTIONS, FOLLOWED BY THE SIMULTANEOUS INITIATION OF MEDICATION ASSISTED THERAPY (MAT), TO ENABLE PSYCHOLOGICAL EXTINCTION, AND STEADY PRO-DOPAMINERGIC THERAPY WITH THE GOAL OF DEVELOPING "DOPAMINE HOMEOSTASIS" IS RECOMMENDED. THE OBJECTIVE OF THESE INTERVENTIONS IS TO PREVENT FUTURE RELAPSE BY TREATING ALL "REWARD DEFICIENCY SYNDROME" (RDS) BEHAVIORS AND EVENTUALLY MAKE AN ADDICTION-FREE LIFE POSSIBLE. 2017 5 1091 29 COGNITIVE ENHANCERS AS A TREATMENT FOR HEROIN RELAPSE AND ADDICTION. HEROIN ADDICTION IS A DISORDER THAT STEMS FROM MALADAPTIVE PLASTICITY WITHIN NEURAL CIRCUITS AND PRODUCES BROAD COGNITIVE DEFICITS. DESPITE CONSIDERABLE ADVANCES IN PSYCHOTHERAPY AND PHARMACOTHERAPY FOR HEROIN RELAPSE AND ADDICTION, EFFECTIVE TREATMENTS FOR HEROIN USE DISORDER ARE STILL LACKING. INCREASING PRECLINICAL EVIDENCE INDICATES THAT HEROIN SEEKING BEHAVIOR IS PERSISTENT AFTER WITHDRAWAL, WHILE COGNITIVE DYSFUNCTIONS ASSOCIATED WITH CHRONIC HEROIN USE ARE AN IMPORTANT CONTRIBUTING FACTOR TO RISK OF HEROIN RELAPSE AND ADDICTION. COGNITIVE ENHANCERS MAY BE USED TO STIMULATE TREATMENT SUCCESS AND ENHANCE TREATMENT EFFICACY. THE PURPOSE OF THIS REVIEW IS TO OUTLINE THE LITERATURE THAT DEMONSTRATES THE COGNITIVE DEFICITS DURING THE DEVELOPMENT OF HEROIN ADDICTION AND WITHDRAWAL PROCESS, AND SEVERAL FACTORS THAT UNDERLINE THE EFFICACY OF COGNITIVE ENHANCERS FOR HEROIN USE DISORDERS. THE REVIEW, THEN, EXAMINES THE POTENTIAL USE AND PHARMACOLOGICAL MECHANISMS OF COGNITIVE ENHANCERS THAT ACT ON CHOLINERGIC, GLUTAMATERGIC, DOPAMINERGIC OR ADRENERGIC PATHWAYS. IT ALSO EXAMINES THE EFFECTS OF COMPOUNDS THAT ALTER CREB SIGNALING AND EPIGENETIC MECHANISMS IN ANIMAL MODEL OF HEROIN RELAPSE. THE CURRENT BODY OF RESEARCH REVEALS THE NEW INSIGHTS INTO THE PHARMACOLOGICAL MECHANISMS UNDERLYING HEROIN ADDICTION AND HOLDS A SIGNIFICANT PROMISE FOR COGNITIVE ENHANCERS AS AN IMPROVED APPROACH TO TREAT HEROIN USE DISORDER IN A MORE EFFICIENT AND PERSISTENT WAY. 2019 6 1252 27 CURRENT PERSPECTIVES ON THE NEUROBIOLOGY OF DRUG ADDICTION: A FOCUS ON GENETICS AND FACTORS REGULATING GENE EXPRESSION. DRUG ADDICTION IS A CHRONIC, RELAPSING DISORDER DEFINED BY CYCLIC PATTERNS OF COMPULSIVE DRUG SEEKING AND TAKING INTERSPERSED WITH EPISODES OF ABSTINENCE. WHILE GENETIC VARIABILITY MAY INCREASE THE RISK OF ADDICTIVE BEHAVIOURS IN AN INDIVIDUAL, EXPOSURE TO A DRUG RESULTS IN NEUROADAPTATIONS IN INTERCONNECTED BRAIN CIRCUITS WHICH, IN SUSCEPTIBLE INDIVIDUALS, ARE BELIEVED TO UNDERLIE THE TRANSITION TO, AND MAINTENANCE OF, AN ADDICTED STATE. THESE ADAPTATIONS CAN OCCUR AT THE CELLULAR, MOLECULAR, OR (EPI)GENETIC LEVEL AND ARE ASSOCIATED WITH SYNAPTIC PLASTICITY AND ALTERED GENE EXPRESSION, THE LATTER BEING MEDIATED VIA BOTH FACTORS AFFECTING TRANSLATION (EPIGENETICS) AND TRANSCRIPTION (NON CODING MICRORNAS) OF THE DNA OR RNA ITSELF. NEW ADVANCES USING TECHNIQUES SUCH AS OPTOGENETICS HAVE THE POTENTIAL TO INCREASE OUR UNDERSTANDING OF THE MICROCIRCUITRY MEDIATING ADDICTIVE BEHAVIOURS. HOWEVER, THE PROCESSES LEADING TO ADDICTION ARE COMPLEX AND MULTIFACTORIAL AND THUS WE FACE A MAJOR CONTEMPORARY CHALLENGE TO ELUCIDATE THE FACTORS IMPLICATED IN THE DEVELOPMENT AND MAINTENANCE OF AN ADDICTED STATE. 2012 7 3094 41 GENOMIC AND PERSONALIZED MEDICINE APPROACHES FOR SUBSTANCE USE DISORDERS (SUDS) LOOKING AT GENOME-WIDE ASSOCIATION STUDIES. DRUG ADDICTION, OR SUBSTANCE USE DISORDER (SUD), IS A CHRONIC, RELAPSING DISORDER IN WHICH COMPULSIVE DRUG-SEEKING AND DRUG-TAKING BEHAVIOUR PERSIST DESPITE SERIOUS NEGATIVE CONSEQUENCES. DRUG ABUSE REPRESENTS A PROBLEM THAT DESERVES GREAT ATTENTION FROM A SOCIAL POINT OF VIEW, AND FOCUSES ON THE IMPORTANCE OF GENETIC STUDIES TO HELP IN UNDERSTANDING THE GENETIC BASIS OF ADDICTION AND ITS MEDICAL TREATMENT. DESPITE THE COMPLEXITY OF DRUG ADDICTION DISORDERS, AND THE HIGH NUMBER OF ENVIRONMENTAL VARIABLES PLAYING A ROLE IN THE ONSET, RECURRENCE, AND DURATION OF THE SYMPTOMS, SEVERAL STUDIES HAVE HIGHLIGHTED THE NON-NEGLIGIBLE ROLE OF GENETICS, AS DEMONSTRATED BY HERITABILITY AND GENOME-WIDE ASSOCIATION STUDIES. A CORRELATION BETWEEN THE RELATIVE RISK OF ADDICTION TO SPECIFIC SUBSTANCES AND HERITABILITY HAS BEEN RECENTLY OBSERVED, SUGGESTING THAT NEUROBIOLOGICAL MECHANISMS MAY BE, AT LEAST IN PART, INHERITED. ALL THESE OBSERVATIONS POINT TOWARDS A SCENARIO WHERE THE CORE NEUROBIOLOGICAL FACTORS OF ADDICTION, INVOLVING THE REWARD SYSTEM, IMPULSIVITY, COMPULSIVITY, STRESS, AND ANXIETY RESPONSE, ARE TRANSMITTED, AND THEREFORE, GENES AND MUTATIONS UNDERLYING THEIR VARIATION MIGHT BE DETECTED. IN THE LAST FEW YEARS, THE DEVELOPMENT OF NEW AND MORE EFFICIENT SEQUENCING TECHNOLOGIES HAS PAVED THE WAY FOR LARGE-SCALE STUDIES IN SEARCHING FOR GENETIC AND EPIGENETIC FACTORS AFFECTING DRUG ADDICTION DISORDERS AND THEIR TREATMENTS. THESE STUDIES HAVE BEEN CRUCIAL TO PINPOINT SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) IN GENES THAT AFFECT THE REACTION TO MEDICAL TREATMENTS. THIS IS CRITICALLY IMPORTANT TO IDENTIFY PHARMACOGENOMIC APPROACHES FOR SUBSTANCE USE DISORDER, SUCH AS OPRM1 SNPS AND METHADONE REQUIRED DOSES FOR MAINTENANCE TREATMENT (MMT). NEVERTHELESS, DESPITE THE PROMISING RESULTS OBTAINED BY GENOME-WIDE ASSOCIATION AND PHARMACOGENOMIC STUDIES, SPECIFIC STUDIES RELATED TO POPULATION GENETICS DIVERSITY ARE LACKING, UNDERMINING THE OVERALL APPLICABILITY OF THE PRELIMINARY FINDINGS, AND THUS POTENTIALLY AFFECTING THE PORTABILITY AND THE ACCURACY OF THE GENETIC STUDIES. IN THIS REVIEW, FOCUSING ON CANNABIS, COCAINE AND HEROIN USE, WE REPORT THE STATE-OF-THE-ART GENOMICS AND PHARMACOGENOMICS OF SUDS, AND THE POSSIBLE FUTURE PERSPECTIVES RELATED TO MEDICAL TREATMENT RESPONSE IN PEOPLE THAT ASK FOR ASSISTANCE IN SOLVING DRUG-RELATED PROBLEMS. 2021 8 4911 19 PAIN IMAGING: FUTURE APPLICATIONS TO INTEGRATIVE CLINICAL AND BASIC NEUROBIOLOGY. WE HAVE ENTERED A NEW ERA IN UNDERSTANDING CNS CIRCUITRY INVOLVED IN ACUTE AND CHRONIC PAIN. THE ABILITY TO OBJECTIVELY MEASURE A PAIN OR ANALGESIC STATE OF THE BRAIN USING NON-INVASIVE METHODS THAT DEFINE NEURAL ACTIVATION PROVIDES THE POSSIBILITY FOR TOP-DOWN APPROACHES TO DRUG DISCOVERY. THESE BRAIN MAPS REPRESENT THE SPECIFIC BRAIN STATE. IN THE FUTURE, CORRELATIONS WITH SUCH STATES AND BEHAVIORAL, GENETIC, EPIGENETIC OR OTHER CHEMICAL MARKERS MAY HELP DEFINE SPECIFIC DIAGNOSTIC TOOLS AND NOVEL APPROACHES TO DRUG DISCOVERY. 2003 9 1651 50 DOPAMINE AND GLUCOSE, OBESITY, AND REWARD DEFICIENCY SYNDROME. OBESITY AS A RESULT OF OVEREATING AS WELL AS A NUMBER OF WELL DESCRIBED EATING DISORDERS HAS BEEN ACCURATELY CONSIDERED TO BE A WORLD-WIDE EPIDEMIC. RECENTLY A NUMBER OF THEORIES BACKED BY A PLETHORA OF SCIENTIFICALLY SOUND NEUROCHEMICAL AND GENETIC STUDIES PROVIDE STRONG EVIDENCE THAT FOOD ADDICTION IS SIMILAR TO PSYCHOACTIVE DRUG ADDICTION. OUR LABORATORY HAS PUBLISHED ON THE CONCEPT KNOWN AS REWARD DEFICIENCY SYNDROME (RDS) WHICH IS A GENETIC AND EPIGENETIC PHENOMENA LEADING TO IMPAIRMENT OF THE BRAIN REWARD CIRCUITRY RESULTING IN A HYPO-DOPAMINERGIC FUNCTION. RDS INVOLVES THE INTERACTIONS OF POWERFUL NEUROTRANSMITTERS AND RESULTS IN ABNORMAL CRAVING BEHAVIOR. A NUMBER OF IMPORTANT FACTS WHICH COULD HELP TRANSLATE TO POTENTIAL THERAPEUTIC TARGETS ESPOUSED IN THIS FOCUSED REVIEW INCLUDE: (1) CONSUMPTION OF ALCOHOL IN LARGE QUANTITIES OR CARBOHYDRATES BINGING STIMULATES THE BRAIN'S PRODUCTION OF AND UTILIZATION OF DOPAMINE; (2) IN THE MESO-LIMBIC SYSTEM THE ENKEPHALINERGIC NEURONS ARE IN CLOSE PROXIMITY, TO GLUCOSE RECEPTORS; (3) HIGHLY CONCENTRATED GLUCOSE ACTIVATES THE CALCIUM CHANNEL TO STIMULATE DOPAMINE RELEASE FROM P12 CELLS; (4) A SIGNIFICANT CORRELATION BETWEEN BLOOD GLUCOSE AND CEREBROSPINAL FLUID CONCENTRATIONS OF HOMOVANILLIC ACID THE DOPAMINE METABOLITE; (5) 2-DEOXYGLUCOSE (2DG), THE GLUCOSE ANALOG, IN PHARMACOLOGICAL DOSES IS ASSOCIATED WITH ENHANCED DOPAMINE TURNOVER AND CAUSES ACUTE GLUCOPRIVATION. EVIDENCE FROM ANIMAL STUDIES AND FMRI IN HUMANS SUPPORT THE HYPOTHESIS THAT MULTIPLE, BUT SIMILAR BRAIN CIRCUITS ARE DISRUPTED IN OBESITY AND DRUG DEPENDENCE AND FOR THE MOST PART, IMPLICATE THE INVOLVEMENT OF DA-MODULATED REWARD CIRCUITS IN PATHOLOGIC EATING BEHAVIORS. BASED ON A CONSENSUS OF NEUROSCIENCE RESEARCH TREATMENT OF BOTH GLUCOSE AND DRUG LIKE COCAINE, OPIATES SHOULD INCORPORATE DOPAMINE AGONIST THERAPY IN CONTRAST TO CURRENT THEORIES AND PRACTICES THAT UTILIZES DOPAMINE ANTAGONISTIC THERAPY. CONSIDERING THAT UP UNTIL NOW CLINICAL UTILIZATION OF POWERFUL DOPAMINE D2 AGONISTS HAVE FAILED DUE TO CHRONIC DOWN REGULATION OF D2 RECEPTORS NEWER TARGETS BASED ON NOVEL LESS POWERFUL D2 AGONISTS THAT UP-REGULATE D2 RECEPTORS SEEMS PRUDENT. WE ENCOURAGE NEW STRATEGIES TARGETED AT IMPROVING DA FUNCTION IN THE TREATMENT AND PREVENTION OF OBESITY A SUBTYPE OF REWARD DEFICIENCY. 2014 10 4846 21 OPIATE ADDICTION AND COCAINE ADDICTION: UNDERLYING MOLECULAR NEUROBIOLOGY AND GENETICS. ADDICTIVE DISEASES, INCLUDING ADDICTION TO HEROIN, PRESCRIPTION OPIOIDS, OR COCAINE, POSE MASSIVE PERSONAL AND PUBLIC HEALTH COSTS. ADDICTIONS ARE CHRONIC RELAPSING DISEASES OF THE BRAIN CAUSED BY DRUG-INDUCED DIRECT EFFECTS AND PERSISTING NEUROADAPTATIONS AT THE EPIGENETIC, MRNA, NEUROPEPTIDE, NEUROTRANSMITTER, OR PROTEIN LEVELS. THESE NEUROADAPTATIONS, WHICH CAN BE SPECIFIC TO DRUG TYPE, AND THEIR RESULTANT BEHAVIORS ARE MODIFIED BY VARIOUS INTERNAL AND EXTERNAL ENVIRONMENTAL FACTORS, INCLUDING STRESS RESPONSIVITY, ADDICT MINDSET, AND SOCIAL SETTING. SPECIFIC GENE VARIANTS, INCLUDING VARIANTS ENCODING PHARMACOLOGICAL TARGET PROTEINS OR GENES MEDIATING NEUROADAPTATIONS, ALSO MODIFY VULNERABILITY AT PARTICULAR STAGES OF ADDICTION. GREATER UNDERSTANDING OF THESE INTERACTING FACTORS THROUGH LABORATORY-BASED AND TRANSLATIONAL STUDIES HAVE THE POTENTIAL TO OPTIMIZE EARLY INTERVENTIONS FOR THE THERAPY OF CHRONIC ADDICTIVE DISEASES AND TO REDUCE THE BURDEN OF RELAPSE. HERE, WE REVIEW THE MOLECULAR NEUROBIOLOGY AND GENETICS OF OPIATE ADDICTION, INCLUDING HEROIN AND PRESCRIPTION OPIOIDS, AND COCAINE ADDICTION. 2012 11 3472 29 IDENTIFICATION AND MANAGEMENT OF PAIN MEDICATION ABUSE AND MISUSE: CURRENT STATE AND FUTURE DIRECTIONS. LONG-TERM OPIOID THERAPY POSES A RISK FOR ABUSE AND MISUSE IN SOME PATIENTS. IDENTIFYING WHICH PATIENTS MAY POTENTIALLY BE AT RISK PRIOR TO INITIATION OF THERAPY, AND IDENTIFYING PATIENTS IN WHOM THESE PROBLEMS DEVELOP DURING THERAPY, ARE SIGNIFICANT CHALLENGES. OUTCOME PREDICTION IS IMPEDED BY THE COMPLEXITY OF THE PROBLEM, WHERE CONSIDERABLE HETEROGENEITY RESULTS FROM PSYCHOLOGICAL AND SOCIOECONOMIC FACTORS, AS WELL AS INTERINDIVIDUAL VARIATION IN BIOLOGICAL PATHWAYS DUE TO GENETIC AND EPIGENETIC FACTORS. SCREENING TOOLS DESIGNED TO DETECT OPIOID MISUSE AND URINE DRUG TESTING ARE BOTH USED CLINICALLY; SCANT EVIDENCE CURRENTLY EXISTS TO ALLOW THE FORMULATION OF AN ALGORITHM FOR JUDICIOUS USE OF THESE TOOLS. MOREOVER, THESE TOOLS MAY NOT BE ADDRESSING THE UNDERLYING ALTERATIONS IN BIOLOGICAL PATHWAYS THAT OCCUR OWING TO THE DEVELOPMENT OF CHRONIC PAIN OR IN RESPONSE TO CHRONIC OPIOID ADMINISTRATION. AN EVIDENCE-BASED ALGORITHMIC APPROACH TO RISK MITIGATION THAT CAN BE APPLIED IN A COST-EFFECTIVE MANNER TO GUIDE THERAPY IS URGENTLY NEEDED. 2012 12 265 40 ADVERSE EFFECTS OF RECREATIONAL AND MEDICAL CANNABIS. PURPOSE OF REVIEW: THIS COMPREHENSIVE REVIEW DISCUSSES THE ADVERSE EFFECTS KNOWN TODAY ABOUT MARIJUANA, FOR EITHER MEDICAL OR RECREATIONAL USE. IT REVIEWS THE ROLE OF CANNABIS IN THE TREATMENT OF CHRONIC PAIN, COGNITIVE AND NEUROLOGICAL ADVERSE EFFECTS, SPECIAL CASES AND ADDICTION. RECENT FINDINGS: CANNABINOIDS WORK THROUGH THE ENDOCANNABINOIDS SYSTEM AND INHIBIT THE RELEASE OF GABA AND GLUTAMATE IN THE BRAIN, IMPACT NEUROMODULATION, AS WELL AS DOPAMINE, ACETYLCHOLINE AND NOREPINEPHRINE RELEASE. THEY AFFECT REWARD, LEARNING AND PAIN. THE USE OF CANNABIS IS INCREASING NATIONALLY AND WORLD-WIDE FOR BOTH RECREATIONAL AND MEDICINAL PURPOSES, HOWEVER, THERE IS RELATIVELY ONLY LOW QUALITY EVIDENCE TO THE EFFICACY AND ADVERSE EFFECTS OF THIS. CANNABIS AND ITS DERIVATIVES MAY BE USED FOR TREATMENT OF CHRONIC PAIN. THEY ARE VIA CB1 RECEPTORS THAT ARE THOUGHT TO MODULATE NOCICEPTIVE SIGNALS IN THE BRAIN. CB2 RECEPTORS IN THE DRG LIKELY AFFECT PAIN INTEGRATION IN THE AFFERENT PATHWAYS, AND PERIPHERALLY CB2 ALSO AFFECTS NORADRENERGIC PATHWAYS INFLUENCING PAIN. A LARGE PROPORTION OF USERS MAY SEE MORE THAN 50% OF CHRONIC PAIN ALLEVIATION COMPARED WITH PLACEBO. CANNABIS AFFECTS COGNITION, MOST NOTABLY EXECUTIVE FUNCTION, MEMORY AND ATTENTION, AND MAY DETERIORATE THE BOUNDARY BETWEEN EMOTIONAL AND EXECUTIVE PROCESSING. CANNABIS IMPAIRS MEMORY IN THE SHORT RUN, WHICH BECOME MORE SIGNIFICANT WITH CHRONIC USE, AND MAY ALSO BE ACCOMPANIED BY POORER EFFORT, SLOWER PROCESSING AND IMPACTED ATTENTION. IT IS GENERALLY BELIEVED THAT LONG-TERM USE AND EARLIER AGE ARE RISK FACTOR FOR NEUROCOGNITIVE DEFICITS; NEUROIMAGING STUDIES HAVE SHOWN REDUCED HIPPOCAMPAL VOLUME AND DENSITY. EXECUTIVE FUNCTIONS AND MEMORY ARE WORSE IN ADOLESCENT USERS VERSUS ADULTS. CANNABIS ADDICTION IS DIFFERENT AND LIKELY LESS COMMON THAN OTHER ADDICTIVE SUBSTANCES, BUT UP TO 10% OF USERS MEET CRITERIA FOR LIFETIME CANNABIS DEPENDENCE. ADDICTION PATTERNS MAY BE LINKED TO GENETIC AND EPIGENETIC DIFFERENCES. IT IS STILL UNCLEAR WHETHER ABSTINENCE REVERSES PATTERNS OF ADDICTION, AND MORE RESEARCH IS REQUIRED INTO THIS TOPIC. SUMMARY: CANNABIS USE HAS BECOME MORE ABUNDANT FOR BOTH MEDICAL AND RECREATIONAL USE. IT CARRIES LIKELY BENEFITS IN THE FORM OF ANALGESIA, ANTI-EMESIS AND IMPROVED APPETITE IN CHRONIC PATIENTS. THE EVIDENCE REVIEWING ADVERSE EFFECTS OF THIS USE ARE STILL LIMITED, HOWEVER, EXITING DATA POINTS TO A CLEAR LINK WITH NEUROCOGNITIVE DETERIORATION, BACKED BY LOSS OF BRAIN VOLUME AND DENSITY. ADDICTION IS LIKELY COMPLEX AND VARIABLE, AND NO GOOD DATA EXISTS TO SUPPORT TREATMENT AT THIS POINT. IT IS BECOMING CLEAR THAT USE IN EARLIER AGES CARRIES A HIGHER RISK FOR LONG-TERM DEFICITS. AS WITH ANY OTHER DRUG, THESE RISKS SHOULD BE CONSIDERED ALONGSIDE BENEFITS PRIOR TO A DECISION ON CANNABIS USE. 2021 13 5649 22 SEX DIFFERENCES IN PSYCHOSTIMULANT ABUSE: IMPLICATIONS FOR ESTROGEN RECEPTORS AND HISTONE DEACETYLASES. SUBSTANCE ABUSE IS A CHRONIC PATHOLOGICAL DISORDER THAT NEGATIVELY AFFECTS MANY HEALTH AND NEUROLOGICAL PROCESSES. A GROWING BODY OF LITERATURE HAS REVEALED GENDER DIFFERENCES IN SUBSTANCE USE. COMPARED TO MEN, WOMEN DISPLAY DISTINCT DRUG-USE PHENOTYPES ACCOMPANIED BY RECOVERY AND REHABILITATION DISPARITIES. THESE OBSERVATIONS HAVE LED TO THE NOTION THAT SEX-DEPENDENT SUSCEPTIBILITIES EXIST ALONG THE PROGRESSION TO ADDICTION. WITHIN THIS SCOPE, NEUROADAPTATIONS FOLLOWING PSYCHOSTIMULANT EXPOSURE ARE THOUGHT TO BE DISTINCT FOR EACH SEX. THIS REVIEW SUMMARIZES CLINICAL FINDINGS AND ANIMAL RESEARCH REPORTING SEX DIFFERENCES IN THE SUBJECTIVE AND BEHAVIORAL RESPONSES TO COCAINE, METHAMPHETAMINE, AND NICOTINE. THIS DISCUSSION IS FOLLOWED BY AN EXAMINATION OF EPIGENETIC AND MOLECULAR ALTERATIONS IMPLICATED IN THE ADDICTION PROCESS. SPECIAL CONSIDERATION IS GIVEN TO HISTONE DEACETYLASES AND ESTROGEN RECEPTOR-MEDIATED GENE EXPRESSION. 2022 14 2573 25 EPIGENETICS OF DRUG ABUSE: PREDISPOSITION OR RESPONSE. DRUG ADDICTION CONTINUES TO BE A SERIOUS MEDICAL AND SOCIAL PROBLEM. VULNERABILITY TO DEVELOP AN ADDICTION TO DRUGS IS DEPENDENT ON GENETIC, ENVIRONMENTAL, SOCIAL AND BIOLOGICAL FACTORS. IN PARTICULAR, THE INTERACTIONS OF ENVIRONMENTAL AND GENETIC FACTORS INDICATE THE SIGNIFICANCE OF EPIGENETIC MECHANISMS, WHICH HAVE BEEN FOUND TO OCCUR IN RESPONSE TO ILLICIT DRUG USE OR AS UNDERLYING FACTORS IN CHRONIC SUBSTANCE ABUSE AND RELAPSE. EPIGENETICS IS DEFINED AS THE HERITABLE AND POSSIBLY REVERSIBLE MODIFICATIONS IN GENE EXPRESSION THAT DO NOT INVOLVE ALTERATIONS IN THE DNA SEQUENCE. THIS REVIEW DISCUSSES THE VARIOUS TYPES OF EPIGENETIC MODIFICATIONS AND THEIR RELEVANCE TO DRUG ADDICTION TO ELUCIDATE WHETHER EPIGENETICS IS A PREDISPOSING FACTOR, OR A RESPONSE TO, DEVELOPING AN ADDICTION TO DRUGS OF ABUSE. 2012 15 4327 34 MICRORNAS MODULATE INTERACTIONS BETWEEN STRESS AND RISK FOR COCAINE ADDICTION. EXPOSURE TO STRESS INCREASES VULNERABILITY TO DRUG ABUSE, AS WELL AS RELAPSE LIABILITY IN ADDICTED INDIVIDUALS. CHRONIC DRUG USE ALTERS STRESS RESPONSE IN A MANNER THAT INCREASES DRUG SEEKING BEHAVIORS AND RELAPSE. DRUG EXPOSURE AND WITHDRAWAL HAVE BEEN SHOWN TO ALTER STRESS RESPONSES, AND CORTICOSTEROID MEDIATORS OF STRESS HAVE BEEN SHOWN TO IMPACT ADDICTION-RELATED BRAIN FUNCTION AND DRUG-SEEKING BEHAVIOR. DESPITE THE DOCUMENTED INTERPLAY BETWEEN STRESS AND SUBSTANCE ABUSE, THE MECHANISMS BY WHICH STRESS EXPOSURE AND DRUG SEEKING INTERACT REMAIN LARGELY UNKNOWN. RECENT STUDIES INDICATE THAT MICRORNAS (MIRNA) PLAY A SIGNIFICANT ROLE IN STRESS MODULATION AS WELL AS ADDICTION-RELATED PROCESSES INCLUDING NEUROGENESIS, SYNAPSE DEVELOPMENT, PLASTICITY, DRUG ACQUISITION, WITHDRAWAL AND RELAPSE. MIRNAS ARE SHORT NON-CODING RNAS THAT FUNCTION AS BIDIRECTIONAL EPIGENETIC MODULATORS OF GENE EXPRESSION THROUGH IMPERFECT SEQUENCE TARGETED DEGRADATION AND/OR TRANSLATIONAL REPRESSION OF MRNAS. THEY SERVE AS DYNAMIC REGULATORS OF CNS PHYSIOLOGY AND PATHOPHYSIOLOGY, AND FACILITATE RAPID AND LONG-LASTING CHANGES TO COMPLEX SYSTEMS AND BEHAVIORS. MIRNAS FUNCTION IN GLUCOCORTICOID SIGNALING AND THE MESOLIMBIC DOPAMINE REWARD SYSTEM, AS WELL AS MOOD DISORDERS RELATED TO DRUG WITHDRAWAL. THE LITERATURE SUGGESTS MIRNAS PLAY A PIVOTAL ROLE IN THE INTERACTION BETWEEN EXPOSURES TO STRESS, ADDICTION-RELATED PROCESSES, AND NEGATIVE AFFECTIVE STATES RESULTING FROM EXTENDED DRUG WITHDRAWAL. THIS MANUSCRIPT REVIEWS RECENT EVIDENCE FOR THE ROLE OF MIRNAS IN THE MODULATION OF STRESS AND COCAINE RESPONSES, AND DISCUSSES POTENTIAL MEDIATION OF THE INTERACTION OF THESE SYSTEMS BY MIRNAS. UNCOVERING THE MECHANISM BEHIND THE ASSOCIATION OF STRESS AND DRUG TAKING HAS THE POTENTIAL TO IMPACT THE TREATMENT OF DRUG ABUSE AND PREVENTION OF RELAPSE. FURTHER COMPREHENSION OF THESE COMPLEX INTERACTIONS MAY PROVIDE PROMISING NEW TARGETS FOR THE TREATMENT OF DRUG ADDICTION. 2016 16 1796 33 EFFECT OF GERM-FREE STATUS ON TRANSCRIPTIONAL PROFILES IN THE NUCLEUS ACCUMBENS AND TRANSCRIPTOMIC RESPONSE TO CHRONIC MORPHINE. OPIOID USE DISORDER IS A PUBLIC HEALTH CRISIS THAT CAUSES TREMENDOUS SUFFERING FOR PATIENTS AS WELL AS SUBSTANTIAL SOCIAL AND ECONOMIC COSTS FOR SOCIETY. THERE ARE CURRENTLY AVAILABLE TREATMENTS FOR PATIENTS WITH OPIOID USE DISORDER, BUT THEY REMAIN INTOLERABLE OR INEFFECTIVE FOR MANY. THUS THE NEED TO DEVELOP NEW AVENUES FOR THERAPEUTICS DEVELOPMENT IN THIS SPACE IS GREAT. SUBSTANTIAL WORK IN MODELS OF SUBSTANCE USE DISORDERS, INCLUDING OPIOID USE DISORDER, DEMONSTRATES THAT PROLONGED EXPOSURE TO DRUGS OF ABUSE LEADS TO MARKED TRANSCRIPTIONAL AND EPIGENETIC DYSREGULATION IN LIMBIC SUBSTRUCTURES. IT IS WIDELY BELIEVED THAT THESE CHANGES IN GENE REGULATION IN RESPONSE TO DRUGS ARE A KEY DRIVING FACTOR IN THE PERPETUATION OF DRUG TAKING AND SEEKING BEHAVIORS. THUS, DEVELOPMENT OF INTERVENTIONS THAT COULD SHAPE TRANSCRIPTIONAL REGULATION IN RESPONSE TO DRUGS OF ABUSE WOULD BE OF HIGH VALUE. OVER THE PAST DECADE THERE HAS BEEN A SURGE IN RESEARCH DEMONSTRATING THAT THE RESIDENT BACTERIA OF THE GASTROINTESTINAL TRACT, COLLECTIVELY THE GUT MICROBIOME, CAN HAVE TREMENDOUS INFLUENCE ON NEUROBIOLOGICAL AND BEHAVIORAL PLASTICITY. PREVIOUS WORK FROM OUR GROUP AND OTHERS HAS DEMONSTRATED THAT ALTERATIONS IN THE GUT MICROBIOME CAN ALTER BEHAVIORAL RESPONSES TO OPIOIDS IN MULTIPLE PARADIGMS. ADDITIONALLY, WE HAVE PREVIOUSLY REPORTED THAT DEPLETION OF THE GUT MICROBIOME WITH ANTIBIOTICS MARKEDLY SHIFTS THE TRANSCRIPTOME OF THE NUCLEUS ACCUMBENS FOLLOWING PROLONGED MORPHINE EXPOSURE. IN THIS MANUSCRIPT WE PRESENT A COMPREHENSIVE ANALYSIS OF THE EFFECTS OF THE GUT MICROBIOME ON TRANSCRIPTIONAL REGULATION OF THE NUCLEUS ACCUMBENS FOLLOWING MORPHINE BY UTILIZING GERM-FREE, ANTIBIOTIC TREATED, AND CONTROL MICE. THIS ALLOWS FOR DETAILED UNDERSTANDING OF THE ROLE OF THE MICROBIOME IN REGULATING BASELINE TRANSCRIPTOMIC CONTROL, AS WELL AS RESPONSE TO MORPHINE. WE FIND THAT GERM-FREE STATUS LEADS TO A MARKED GENE DYSREGULATION IN A MANNER DISTINCT TO ADULT MICE TREATED WITH ANTIBIOTICS, AND THAT ALTERED GENE PATHWAYS ARE HIGHLY RELATED TO CELLULAR METABOLIC PROCESSES. THESE DATA PROVIDE ADDITIONAL INSIGHT INTO THE ROLE OF THE GUT MICROBIOME IN MODULATING BRAIN FUNCTION AND LAY A FOUNDATION FOR FURTHER STUDY IN THIS AREA. 2023 17 6617 31 UNDERPINNING THE NEUROBIOLOGICAL INTRICACIES ASSOCIATED WITH OPIOID TOLERANCE. THE OPIOID CRISIS IS A MAJOR THREAT OF THE 21ST CENTURY, WITH A REMARKABLE JUXTAPOSITION OF USE AND ABUSE. OPIOIDS ARE THE MOST POTENT AND EFFICACIOUS CLASS OF ANALGESICS, BUT DESPITE THEIR PROVEN THERAPEUTIC EFFICACY, THEY HAVE RECENTLY BEEN DEGRADED TO THIRD-LINE THERAPY FOR THE MANAGEMENT OF CHRONIC PAIN IN CLINICS. THE REASON BEHIND THIS IS THE DEVELOPMENT OF POTENTIAL SIDE EFFECTS AND TOLERANCE AFTER REPEATED DOSING. OPIOID TOLERANCE IS THE MAJOR LIMITING FACTOR LEADING TO THE WITHDRAWAL OF TREATMENT, SEVERE SIDE EFFECTS DUE TO DOSE ESCALATION, AND SOMETIMES EVEN DEATH OF THE PATIENTS. EVERY DAY MORE THAN 90 PEOPLE DIE DUE TO OPIOIDS OVERDOSE IN AMERICA, AND A SIMILAR TREND HAS BEEN SEEN ACROSS THE GLOBE. OVER THE PAST TWO DECADES, RESEARCHERS HAVE BEEN TRYING TO DISSECT THE NEUROBIOLOGICAL MECHANISM OF OPIOID TOLERANCE. RESEARCH ON OPIOID TOLERANCE SHIFTED TOWARD CENTRAL NERVOUS SYSTEM-BASED ADAPTATIONS BECAUSE TOLERANCE IS MUCH MORE THAN JUST A CELLULAR PHENOMENON. THUS, NEUROBIOLOGICAL ADAPTATIONS ASSOCIATED WITH OPIOID TOLERANCE ARE IMPORTANT TO UNDERSTAND IN ORDER TO FIND NEWER PAIN THERAPEUTICS. THESE ADAPTATIONS ARE ASSOCIATED WITH ALTERATIONS IN ASCENDING AND DESCENDING PAIN PATHWAYS, REWARD CIRCUITRY MODULATIONS, RECEPTOR DESENSITIZATION AND DOWN-REGULATION, RECEPTOR INTERNALIZATION, HETERODIMERIZATION, AND ALTERED EPIGENETIC REGULATION. THE PRESENT REVIEW IS FOCUSED ON NOVEL CIRCUITRIES ASSOCIATED WITH OPIOID TOLERANCE IN DIFFERENT AREAS OF THE BRAIN, SUCH AS PERIAQUEDUCTAL GRAY, ROSTRAL VENTROMEDIAL MEDULLA, DORSAL RAPHE NUCLEUS, VENTRAL TEGMENTAL AREA, AND NUCLEUS ACCUMBENS. UNDERSTANDING THE NEUROBIOLOGICAL MODULATIONS ASSOCIATED WITH CHRONIC OPIOID EXPOSURE AND TOLERANCE WILL PAVE THE WAY FOR THE DEVELOPMENT OF NOVEL PHARMACOLOGICAL TOOLS FOR SAFER AND BETTER MANAGEMENT OF CHRONIC PAIN IN PATIENTS. 2020 18 1687 26 DRUGS OF ABUSE: EPIGENETIC MECHANISMS IN TOXICITY AND ADDICTION. THE ABUSE OF SUBSTANCES SUCH AS ETHANOL, COCAINE, AMPHETAMINES AND HEROIN IS ASSOCIATED WITH TOXIC EFFECTS ON ALMOST EVERY SYSTEM OF THE ORGANISM. FURTHERMORE, THE TRANSITION FROM OCCASIONAL-RECREATIONAL USE TO CHRONIC ABUSE AND ADDICTION IS A SERIOUS PSYCHIATRIC DISORDER WITH ONLY FEW CHANCES FOR EFFECTIVE AND DEFINITIVE TREATMENT SINCE MOST INDIVIDUALS RELAPSE, EVEN AFTER LONG PERIODS OF ABSTINENCE. IT IS THEREFORE OF UTMOST IMPORTANCE TO ELUCIDATE THE MECHANISMS BY WHICH THESE SUBSTANCES EXERT THEIR TOXICITY AND MEDIATE ADDICTION, IN ORDER TO DEVELOP NEW, EFFICIENT THERAPEUTIC STRATEGIES WITH A LONG-TERM OUTCOME, WHICH ARE CURRENTLY LACKING. WE ALREADY KNOW THAT IN A GREAT NUMBER OF THESE MECHANISMS, ALTERED GENE FUNCTION IS INVOLVED. BUT, WITH THE NEW FIELD OF EPIGENETICS, THERE IS INCREASING EVIDENCE THAT CHANGES IN THE EPIGENOME ARE RESPONSIBLE FOR THE ALTERED GENE FUNCTION. THE ADVANCES IN THE FIELD OF EPIGENETICS TOWARDS ELUCIDATION OF THE MECHANISMS UNDERLYING TOXICITY AND ADDICTION FOR ETHANOL, COCAINE, AMPHETAMINES AND HEROIN ARE CURRENTLY PRESENTED AND DISCUSSED IN THIS REVIEW. 2011 19 4914 29 PAIN VULNERABILITY: A NEUROBIOLOGICAL PERSPECTIVE. THERE ARE MANY KNOWN RISK FACTORS FOR CHRONIC PAIN CONDITIONS, YET THE BIOLOGICAL UNDERPINNINGS THAT LINK THESE FACTORS TO ABNORMAL PROCESSING OF PAINFUL SIGNALS ARE ONLY JUST BEGINNING TO BE EXPLORED. THIS REVIEW WILL DISCUSS THE POTENTIAL MECHANISMS THAT HAVE BEEN PROPOSED TO UNDERLIE VULNERABILITY AND RESILIENCE TOWARD DEVELOPING CHRONIC PAIN. PARTICULAR FOCUS WILL BE GIVEN TO GENETIC AND EPIGENETIC PROCESSES, PRIMING EFFECTS ON A CELLULAR LEVEL, AND ALTERATIONS IN BRAIN NETWORKS CONCERNED WITH REWARD, MOTIVATION/LEARNING AND DESCENDING MODULATORY CONTROL. ALTHOUGH RESEARCH IN THIS AREA IS STILL IN ITS INFANCY, A BETTER UNDERSTANDING OF HOW PAIN VULNERABILITY EMERGES HAS THE POTENTIAL TO HELP IDENTIFY INDIVIDUALS AT RISK AND MAY OPEN UP NEW THERAPEUTIC AVENUES. 2014 20 1747 17 EARLY LIFE ADVERSITY: EPIGENETIC REGULATION UNDERLYING DRUG ADDICTION SUSCEPTIBILITY. DRUG ADDICTION IS A LEADING CAUSE OF DISABILITY WORLDWIDE, WITH MORE THAN 70,000 AMERICANS DYING FROM DRUG OVERDOSE IN 2019 ALONE. WHILE ONLY A SMALL PERCENTAGE OF CHRONIC DRUG USERS ESCALATE TO DRUG ADDICTION, LITTLE IS UNDERSTOOD ON THE PRECISE MECHANISMS OF THIS SUSCEPTIBILITY. EARLY LIFE ADVERSITY IS CAUSALLY RELEVANT TO ADULT PSYCHIATRIC DISEASE AND MAY CONTRIBUTE TO THE RISK OF ADDICTION. HERE WE REVIEW RECENT PRE-CLINICAL EVIDENCE SHOWING THAT EARLY LIFE EXPOSURE TO STRESS AND/OR DRUGS REGULATES CHANGES IN BEHAVIOR, GENE EXPRESSION, AND THE EPIGENOME THAT PERSIST INTO ADULTHOOD. WE SUMMARIZE THE MAJOR FINDINGS AND GAPS IN THE PRECLINICAL LITERATURE, HIGHLIGHTING STUDIES THAT DEMONSTRATE THE OFTEN PROFOUND DIFFERENCES BETWEEN FEMALE AND MALE SUBJECTS. 2023