1 41 128 A COMPARISON OF NEUROIMAGING ABNORMALITIES IN MULTIPLE SCLEROSIS, MAJOR DEPRESSION AND CHRONIC FATIGUE SYNDROME (MYALGIC ENCEPHALOMYELITIS): IS THERE A COMMON CAUSE? THERE IS COPIOUS EVIDENCE OF ABNORMALITIES IN RESTING-STATE FUNCTIONAL NETWORK CONNECTIVITY STATES, GREY AND WHITE MATTER PATHOLOGY AND IMPAIRED CEREBRAL PERFUSION IN PATIENTS AFFORDED A DIAGNOSIS OF MULTIPLE SCLEROSIS, MAJOR DEPRESSION OR CHRONIC FATIGUE SYNDROME (CFS) (MYALGIC ENCEPHALOMYELITIS). SYSTEMIC INFLAMMATION MAY WELL BE A MAJOR ELEMENT EXPLAINING SUCH FINDINGS. INTER-PATIENT AND INTER-ILLNESS VARIATIONS IN NEUROIMAGING FINDINGS MAY ARISE AT LEAST IN PART FROM REGIONAL GENETIC, EPIGENETIC AND ENVIRONMENTAL VARIATIONS IN THE FUNCTIONS OF MICROGLIA AND ASTROCYTES. REGIONAL DIFFERENCES IN NEURONAL RESISTANCE TO OXIDATIVE AND INFLAMMATORY INSULTS AND IN THE PERFORMANCE OF ANTIOXIDANT DEFENCES IN THE CENTRAL NERVOUS SYSTEM MAY ALSO PLAY A ROLE. IMPORTANTLY, REPLICATED EXPERIMENTAL FINDINGS SUGGEST THAT THE USE OF HIGH-RESOLUTION SPECT IMAGING MAY HAVE THE CAPACITY TO DIFFERENTIATE PATIENTS AFFORDED A DIAGNOSIS OF CFS FROM THOSE WITH A DIAGNOSIS OF DEPRESSION. FURTHER RESEARCH INVOLVING THIS FORM OF NEUROIMAGING APPEARS WARRANTED IN AN ATTEMPT TO OVERCOME THE PROBLEM OF AETIOLOGICALLY HETEROGENEOUS COHORTS WHICH PROBABLY EXPLAIN CONFLICTING FINDINGS PRODUCED BY INVESTIGATIVE TEAMS ACTIVE IN THIS FIELD. HOWEVER, THE IONISING RADIATION AND RELATIVE LACK OF SENSITIVITY INVOLVED PROBABLY PRECLUDE ITS USE AS A ROUTINE DIAGNOSTIC TOOL. 2018 2 6159 36 THE GENETICS AND EPIGENETICS OF FATIGUE. FATIGUE IS A COMMON SYMPTOM AND INCLUDES BOTH PHYSICAL AND MENTAL COMPONENTS. IT CAN BE ASSOCIATED WITH A VARIETY OF DIFFERENT SYNDROMES AND DISEASES, BUT IN MANY CASES IS NOT ASSOCIATED WITH OTHER COMORBID CONDITIONS. MOST HUMANS HAVE EXPERIENCED ACUTE FATIGUE IN RELATION TO DIFFERENT STRESSORS. ACUTE FATIGUE TYPICALLY DECREASES AS THE EFFECT OF THE TRIGGERING FACTOR IS REDUCED AND A NORMAL HOMEOSTATIC BALANCE IS RESTORED. FATIGUE THAT PERSISTS FOR 6 MONTHS OR MORE IS TERMED CHRONIC FATIGUE. CHRONIC FATIGUE (CF) IN COMBINATION WITH A MINIMUM OF 4 OF 8 SYMPTOMS AND THE ABSENCE OF DISEASES THAT COULD EXPLAIN THESE SYMPTOMS, CONSTITUTE THE CASE DEFINITION FOR CHRONIC FATIGUE SYNDROME. IN SPITE OF ITS PREVALENCE, THE BIOLOGY OF FATIGUE IS RELATIVELY POORLY UNDERSTOOD AND BIOLOGICAL MARKERS HAVE NOT YET BEEN IDENTIFIED. THIS LITERATURE SEARCH WAS PERFORMED IN PUBMED TO IDENTIFY RESEARCH ON THE GENETICS AND EPIGENETICS OF FATIGUE. PUBLICATIONS WERE INCLUDED IF FATIGUE WAS A MAJOR TOPIC AND THE TOPIC WAS COMBINED WITH GENETIC AND/OR EPIGENETIC MEASUREMENTS IN ADULT HUMANS. A TOTAL OF 40 PUBLICATIONS WERE IDENTIFIED. ALTHOUGH ALTERED FUNCTIONING IN THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS, THE SEROTONERGIC SYSTEM, AND ASSOCIATIONS WITH INFECTIOUS AGENTS HAVE BEEN IDENTIFIED, THE SEARCH FOR GENETIC OR EPIGENETIC MARKERS OF FATIGUE, EITHER IN THE CONTEXT OF CF OR CHRONIC FATIGUE SYNDROME (CFS) HAS BEEN RELATIVELY UNPRODUCTIVE OR, IN THE CASE OF EPIGENETICS, NONEXISTENT. ALTHOUGH SEVERAL STUDIES, BOTH HYPOTHESIS-TESTING AND HYPOTHESIS-GENERATING, HAVE BEEN PERFORMED TO SEARCH FOR BIOMARKERS, THEY HAVE MOSTLY BEEN UNDERPOWERED, RESTRICTED BY THE HETEROGENEITY OF THE PHENOTYPE, OR LIMITED BY AN UNSYSTEMATIC STUDY DESIGN. TO BE ABLE TO CONFIRM THE HYPOTHESIS THAT RISK FOR, OR LEVELS OF, FATIGUE ARE INFLUENCED BY THE GENETIC OR EPIGENETIC BACKGROUND OF AN INDIVIDUAL, STUDIES NEED TO BE BASED ON LARGER SAMPLE SIZES WITH A MORE CLEARLY DEFINED PHENOTYPE. STUDIES NEED TO FOCUS NOT ONLY ON THE INFLUENCE OF A SINGLE ASPECT SUCH AS SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) OR DIFFERENTIAL GENE EXPRESSION ON DISEASE RISK OR STATE, BUT ALSO ON THE SYSTEMS BIOLOGY BEHIND THE DISEASE IN COMBINATION WITH INFORMATION ON ENVIRONMENTAL INFLUENCES AND VALIDATION OF FINDINGS IN FUNCTIONAL STUDIES. 2010 3 4277 32 MICROGLIA SEQUELAE: BRAIN SIGNATURE OF INNATE IMMUNITY IN SCHIZOPHRENIA. SCHIZOPHRENIA IS A PSYCHIATRIC DISORDER WITH SIGNIFICANT IMPACT ON INDIVIDUALS AND SOCIETY. THE CURRENT PHARMACOLOGIC TREATMENT, WHICH PRINCIPALLY ALLEVIATES PSYCHOSIS, IS FOCUSED ON NEUROTRANSMITTERS MODULATION, RELYING ON DRUGS WITH SEVERE SIDE EFFECTS AND INEFFECTIVENESS IN A SIGNIFICANT PERCENTAGE OF CASES. THEREFORE, AND DUE TO DIFFICULTIES INHERENT TO DIAGNOSIS AND TREATMENT, IT IS VITAL TO REASSESS ALTERNATIVE CELLULAR AND MOLECULAR DRUG TARGETS. DISTINCT RISK FACTORS - GENETIC, DEVELOPMENTAL, EPIGENETIC, AND ENVIRONMENTAL - HAVE BEEN ASSOCIATED WITH DISEASE ONSET AND PROGRESSION, GIVING RISE TO THE PROPOSAL OF DIFFERENT PATHOPHYSIOLOGICAL MECHANISMS AND PUTATIVE PHARMACOLOGICAL TARGETS. IMMUNITY IS INVOLVED AND, PARTICULARLY MICROGLIA - INNATE IMMUNE CELLS OF THE CENTRAL NERVOUS SYSTEM, CRITICALLY INVOLVED IN BRAIN DEVELOPMENT - HAVE CAPTURED ATTENTION AS CELLULAR PLAYERS. MICROGLIA UNDERGO MARKED MORPHOLOGIC AND FUNCTIONAL ALTERATIONS IN THE HUMAN DISEASE, AS WELL AS IN ANIMAL MODELS OF SCHIZOPHRENIA, AS REPORTED IN SEVERAL ORIGINAL PAPERS. WE CLUSTER THE MAIN FINDINGS OF CLINICAL STUDIES BY GROUPS OF PATIENTS: (1) AT ULTRA-HIGH RISK OF PSYCHOSIS, (2) WITH A FIRST EPISODE OF PSYCHOSIS OR RECENT-ONSET SCHIZOPHRENIA, AND (3) WITH CHRONIC SCHIZOPHRENIA; IN TRANSLATIONAL STUDIES, WE HIGHLIGHT THE TIME WINDOW OF APPEARANCE OF PARTICULAR MICROGLIA ALTERATIONS IN THE MOST WELL STUDIED ANIMAL MODEL IN THE FIELD (MATERNAL IMMUNE ACTIVATION). THE ORGANIZATION OF CLINICAL AND TRANSLATIONAL FINDINGS BASED ON SCHIZOPHRENIA-ASSOCIATED MICROGLIA CHANGES IN DIFFERENT PHASES OF THE DISEASE COURSE MAY HELP DEFINING A TEMPORAL PATTERN OF MICROGLIA CHANGES AND MAY DRIVE THE DESIGN OF NOVEL THERAPEUTIC STRATEGIES. 2022 4 6375 36 THE ROLE OF NEURO-IMMUNE INTERACTION IN CHRONIC PAIN CONDITIONS; FUNCTIONAL SOMATIC SYNDROME, NEUROGENIC INFLAMMATION, AND PERIPHERAL NEUROPATHY. FUNCTIONAL SOMATIC SYNDROMES ARE INCREASINGLY DIAGNOSED IN CHRONICALLY ILL PATIENTS PRESENTING WITH AN ARRAY OF SYMPTOMS NOT ATTRIBUTED TO PHYSICAL AILMENTS. CONDITIONS SUCH AS CHRONIC FATIGUE SYNDROME, FIBROMYALGIA SYNDROME, OR IRRITABLE BOWEL SYNDROME ARE COMMON DISORDERS THAT BELONG IN THIS BROAD CATEGORY. SUCH SYNDROMES ARE CHARACTERISED BY THE PRESENCE OF ONE OR MULTIPLE CHRONIC SYMPTOMS INCLUDING WIDESPREAD MUSCULOSKELETAL PAIN, FATIGUE, SLEEP DISORDERS, AND ABDOMINAL PAIN, AMONGST OTHER ISSUES. SYMPTOMS ARE BELIEVED TO RELATE TO A COMPLEX INTERACTION OF BIOLOGICAL AND PSYCHOSOCIAL FACTORS, WHERE A DEFINITE AETIOLOGY HAS NOT BEEN ESTABLISHED. THEORIES SUGGEST CAUSATIVE PATHWAYS BETWEEN THE IMMUNE AND NERVOUS SYSTEMS OF AFFECTED INDIVIDUALS WITH SEVERAL RISK FACTORS IDENTIFIED IN PATIENTS PRESENTING WITH ONE OR MORE FUNCTIONAL SYNDROMES. RISK FACTORS INCLUDING STRESS AND CHILDHOOD TRAUMA ARE NOW RECOGNISED AS IMPORTANT CONTRIBUTORS TO CHRONIC PAIN CONDITIONS. EMOTIONAL, PHYSICAL, AND SEXUAL ABUSE DURING CHILDHOOD IS CONSIDERED A SEVERE STRESSOR HAVING A HIGH PREVALENCE IN FUNCTIONAL SOMATIC SYNDROME SUFFERS. SUCH TRAUMA PERMANENTLY ALTERS THE BIOLOGICAL STRESS RESPONSE OF THE SUFFERS LEADING TO NEUROEXCITATORY AND OTHER NERVE ISSUES ASSOCIATED WITH CHRONIC PAIN IN ADULTS. TRAUMATIC AND CHRONIC STRESS RESULTS IN EPIGENETIC CHANGES IN STRESS RESPONSE GENES, WHICH ULTIMATELY LEADS TO DYSREGULATION OF THE HYPOTHALAMIC-PITUITARY AXIS, THE AUTONOMIC NERVOUS SYSTEM, AND THE IMMUNE SYSTEM MANIFESTING IN A BROAD ARRAY OF SYMPTOMS. IMPORTANTLY, THESE SYSTEMS ARE KNOWN TO BE DYSREGULATED IN PATIENTS SUFFERING FROM FUNCTIONAL SOMATIC SYNDROME. FUNCTIONAL SOMATIC SYNDROMES ARE ALSO HIGHLY PREVALENT CO-MORBIDITIES OF PSYCHIATRIC CONDITIONS, MOOD DISORDERS, AND ANXIETY. CONSEQUENTLY, THIS REVIEW AIMS TO PROVIDE INSIGHT INTO THE ROLE OF THE NERVOUS SYSTEM AND IMMUNE SYSTEM IN CHRONIC PAIN DISORDERS ASSOCIATED WITH THE MUSCULOSKELETAL SYSTEM, AND CENTRAL AND PERIPHERAL NERVOUS SYSTEMS. 2022 5 1736 27 EARLY DETECTION AND PREVENTION OF SCHIZOPHRENIC PSYCHOSIS-A REVIEW. PSYCHOTIC DISORDERS OFTEN RUN A CHRONIC COURSE AND ARE ASSOCIATED WITH A CONSIDERABLE EMOTIONAL AND SOCIAL IMPACT FOR PATIENTS AND THEIR RELATIVES. THEREFORE, EARLY RECOGNITION, COMBINED WITH THE POSSIBILITY OF PREVENTIVE INTERVENTION, IS URGENTLY WARRANTED SINCE THE DURATION OF UNTREATED PSYCHOSIS (DUP) SIGNIFICANTLY DETERMINES THE FURTHER COURSE OF THE DISEASE. IN ADDITION TO ESTABLISHED DIAGNOSTIC TOOLS, NEUROBIOLOGICAL FACTORS IN THE DEVELOPMENT OF SCHIZOPHRENIC PSYCHOSES ARE INCREASINGLY BEING INVESTIGATED. IT IS SHOWN THAT NUMEROUS MOLECULAR ALTERATIONS ALREADY EXIST BEFORE THE CLINICAL ONSET OF THE DISEASE. AS SCHIZOPHRENIC PSYCHOSES ARE NOT ELICITED BY A SINGLE MUTATION IN THE DEOXYRIBONUCLEIC ACID (DNA) SEQUENCE, EPIGENETICS LIKELY CONSTITUTE THE MISSING LINK BETWEEN ENVIRONMENTAL INFLUENCES AND DISEASE DEVELOPMENT AND COULD POTENTIALLY SERVE AS A BIOMARKER. THE RESULTS FROM TRANSCRIPTOMIC AND PROTEOMIC STUDIES POINT TO A DYSREGULATED IMMUNE SYSTEM, LIKELY EVOKED BY EPIGENETIC ALTERATIONS. DESPITE THE INCREASING KNOWLEDGE OF THE NEUROBIOLOGICAL MECHANISMS INVOLVED IN THE DEVELOPMENT OF PSYCHOTIC DISORDERS, FURTHER RESEARCH EFFORTS WITH LARGE POPULATION-BASED STUDY DESIGNS ARE NEEDED TO IDENTIFY SUITABLE BIOMARKERS. IN CONCLUSION, A COMBINATION OF BLOOD EXAMINATIONS, FUNCTIONAL IMAGING TECHNIQUES, ELECTROENCEPHALOGRAPHY (EEG) INVESTIGATIONS AND POLYGENIC RISK SCORES SHOULD BE CONSIDERED AS THE BASIS FOR PREDICTING HOW SUBJECTS WILL TRANSITION INTO MANIFEST PSYCHOSIS. 2021 6 2139 36 EPIGENETIC INSIGHTS INTO MULTIPLE SCLEROSIS DISEASE PROGRESSION. MULTIPLE SCLEROSIS (MS), A CHRONIC INFLAMMATORY DEMYELINATING AND NEURODEGENERATIVE DISEASE OF THE CENTRAL NERVOUS SYSTEM, IS TODAY A LEADING CAUSE OF UNPREDICTABLE LIFELONG DISABILITY IN YOUNG ADULTS. THE TREATMENT OF PATIENTS IN PROGRESSIVE STAGES REMAINS HIGHLY CHALLENGING, ALLUDING TO OUR LIMITED UNDERSTANDING OF THE UNDERLYING PATHOLOGICAL PROCESSES. IN THIS REVIEW, WE PROVIDE INSIGHTS INTO THE MECHANISMS UNDERPINNING MS PROGRESSION FROM A PERSPECTIVE OF EPIGENETICS, THAT REFERS TO STABLE AND MITOTICALLY HERITABLE, YET REVERSIBLE, CHANGES IN THE GENOME ACTIVITY AND GENE EXPRESSION. WE FIRST RECAPITULATE FINDINGS FROM EPIGENETIC STUDIES EXAMINING THE BRAIN TISSUE OF PROGRESSIVE MS PATIENTS, WHICH SUPPORT A CONTRIBUTION OF DNA AND HISTONE MODIFICATIONS IN IMPAIRED OLIGODENDROCYTE DIFFERENTIATION, DEFECTIVE MYELINATION/REMYELINATION AND SUSTAINED NEURO-AXONAL VULNERABILITY. WE NEXT EXPLORE POSSIBILITIES FOR IDENTIFYING FACTORS AFFECTING PROGRESSION USING EASILY ACCESSIBLE TISSUES SUCH AS BLOOD BY COMPARING EPIGENETIC SIGNATURES IN PERIPHERAL IMMUNE CELLS AND BRAIN TISSUE. DESPITE MINOR OVERLAP AT INDIVIDUAL METHYLATION SITES, NEARLY 30% OF ALTERED GENES REPORTED IN PERIPHERAL IMMUNE CELLS OF PROGRESSIVE MS PATIENTS WERE FOUND IN BRAIN TISSUE, JOINTLY CONVERGING ON ALTERATIONS OF NEURONAL FUNCTIONS. WE FURTHER SPECULATE ABOUT THE MECHANISMS UNDERLYING SHARED EPIGENETIC PATTERNS BETWEEN BLOOD AND BRAIN, WHICH LIKELY IMPLY THE INFLUENCE OF INTERNAL (GENETIC CONTROL) AND/OR EXTERNAL (E.G. SMOKING AND AGEING) FACTORS IMPRINTING A COMMON SIGNATURE IN BOTH COMPARTMENTS. OVERALL, WE PROPOSE THAT EPIGENETICS MIGHT SHED LIGHT ON CLINICALLY RELEVANT MECHANISMS INVOLVED IN DISEASE PROGRESSION AND OPEN NEW AVENUES FOR THE TREATMENT OF PROGRESSIVE MS PATIENTS IN THE FUTURE. 2020 7 1314 35 DELINEATING CONDITIONS AND SUBTYPES IN CHRONIC PAIN USING NEUROIMAGING. DIFFERENTIATING SUBTYPES OF CHRONIC PAIN STILL REMAINS A CHALLENGE-BOTH FROM A SUBJECTIVE AND OBJECTIVE POINT OF VIEW. PERSONALIZED MEDICINE IS THE CURRENT GOAL OF MODERN MEDICAL CARE AND IS LIMITED BY THE SUBJECTIVE NATURE OF PATIENT SELF-REPORTING OF SYMPTOMS AND BEHAVIORAL EVALUATION. PHYSIOLOGY-FOCUSED TECHNIQUES SUCH AS GENOME AND EPIGENETIC ANALYSES INFORM THE DELINEATION OF PAIN GROUPS; HOWEVER, EXCEPT UNDER RARE CIRCUMSTANCES, THEY HAVE DILUTED EFFECTS THAT AGAIN, SHARE A COMMON RELIANCE ON BEHAVIORAL EVALUATION. THE APPLICATION OF STRUCTURAL NEUROIMAGING TOWARDS DISTINGUISHING PAIN SUBTYPES IS A GROWING FIELD AND MAY INFORM PAIN-GROUP CLASSIFICATION THROUGH THE ANALYSIS OF BRAIN REGIONS SHOWING HYPERTROPHIC AND ATROPHIC CHANGES IN THE PRESENCE OF PAIN. ANALYTICAL TECHNIQUES SUCH AS MACHINE-LEARNING CLASSIFIERS HAVE THE CAPACITY TO PROCESS LARGE VOLUMES OF DATA AND DELINEATE DIAGNOSTICALLY RELEVANT INFORMATION FROM NEUROIMAGING ANALYSIS. THE ISSUE OF DEFINING A "BRAIN TYPE" IS AN EMERGING FIELD AIMED AT INTERPRETING OBSERVED BRAIN CHANGES AND DELINEATING THEIR CLINICAL IDENTITY/SIGNIFICANCE. IN THIS REVIEW, 2 CHRONIC PAIN CONDITIONS (MIGRAINE AND IRRITABLE BOWEL SYNDROME) WITH SIMILAR CLINICAL PHENOTYPES ARE COMPARED IN TERMS OF THEIR STRUCTURAL NEUROIMAGING FINDINGS. INDEPENDENT INVESTIGATIONS ARE COMPARED WITH FINDINGS FROM APPLICATION OF MACHINE-LEARNING ALGORITHMS. FINDINGS ARE DISCUSSED IN TERMS OF DIFFERENTIATING PATIENT SUBGROUPS USING NEUROIMAGING DATA IN PATIENTS WITH CHRONIC PAIN AND HOW THEY MAY BE APPLIED TOWARDS DEFINING A PERSONALIZED PAIN SIGNATURE THAT HELPS SEGREGATE PATIENT SUBGROUPS (EG, MIGRAINE WITH AND WITHOUT AURA, WITH OR WITHOUT NAUSEA; IRRITABLE BOWEL SYNDROME VS OTHER FUNCTIONAL GASTROINTESTINAL DISORDERS). 2019 8 2963 22 GENETIC AND EPIGENETIC MECHANISMS LINKING PAIN AND PSYCHIATRIC DISORDERS. THE NEUROPHYSIOLOGICAL LINK BETWEEN NEUROPATHIC PAIN AND DEPRESSION REMAINS UNKNOWN DESPITE EVIDENT HIGH COMORBIDITY OF THESE TWO DISORDERS. HOWEVER, THERE IS CONVINCING EVIDENCE THAT GENOTYPE PLAYS A ROLE IN BOTH PAIN AND DEPRESSION. USING VARIOUS TYPES OF GENETIC ANALYSIS - POPULATION GENETICS, CYTOGENETICS AND MOLECULAR TECHNOLOGIES - SPECIFIC GENES HAVE BEEN IMPLICATED IN MEDIATING ALMOST ALL ASPECTS OF NOCICEPTION AND MOOD DISORDERS. THE CURRENT REVIEW ATTEMPTS TO IDENTIFY SPECIFIC GENES AND EPIGENETIC MECHANISMS COMMON TO BOTH DISORDERS. IT IS CONCLUDED THAT EXTERNAL AND INTERNAL FACTORS (INFLAMMATION, STRESS, GENDER, ETC.) THAT CONTRIBUTE TO THE PATHOLOGIES MAY DO SO THROUGH EPIGENETIC MECHANISMS THAT MAY AFFECT EXPRESSION OF THESE PARTICULAR GENES. THE POSSIBLE INVOLVEMENT OF EPIGENETIC REGULATION IN PAIN AND PSYCHIATRIC DISORDERS SUGGESTS THAT TREATMENTS TARGETING EPIGENETIC MECHANISMS THAT MEDIATE ADVERSE LIFE EVENTS SHOULD BE CONSIDERED. 2015 9 641 38 BIOMARKERS OF MAJOR DEPRESSIVE DISORDER: KNOWING IS HALF THE BATTLE. MAJOR DEPRESSIVE DISORDER (MDD) IS A HETEROGENEOUS DISEASE WHICH IS WHY THERE ARE CURRENTLY NO SPECIFIC METHODS TO ACCURATELY TEST THE SEVERITY, ENDOPHENOTYPE OR THERAPY RESPONSE. THIS LACK OF PROGRESS IS PARTLY ATTRIBUTED TO THE COM-PLEXITY AND VARIABILITY OF DEPRESSION, IN ASSOCIATION WITH ANALYTICAL VARIABILITY OF CLINICAL LITERATURE AND THE WIDE NUMBER OF THEORETICALLY COMPLEX BIOMARKERS. THE LITERATURE ACCESSIBLE, INDICATES THAT MARKERS INVOLVED IN INFLAMMATORY, NEURO-TROPHIC AND METABOLIC PROCESSES AND COMPONENTS OF NEUROTRANSMITTERS AND NEUROENDOCRINE SYSTEMS ARE RATHER STRONG INDICATORS TO BE CONSIDERED CLINICALLY AND CAN BE MEASURED THROUGH GENETIC AND EPIGENETIC, TRANSCRIPTOMIC AND PROTEOMIC, METABOLOMICS AND NEUROIMAGING ASSESSMENTS. PROMISING BIOLOGIC SYSTEMS/MARKERS FOUND WERE I.E., GROWTH BIOMARKERS, ENDOCRINE MARKERS, OXIDANT STRESS MARKERS, PROTEOMIC AND CHRONIC INFLAMMATORY MARKERS, ARE DISCUSSED IN THIS REVIEW. SEVERAL LINES OF EVIDENCE SUGGEST THAT A PORTION OF MDD IS A DOPAMINE AGONIST-RESPONSIVE SUBTYPE. THIS REVIEW ANALYZES CONCISE REPORTS ON THE PATHOPHYSIOLOGICAL BIOMARKERS OF MDD AND THERAPEUTIC REACTIONS VIA PERIPHERAL DEVELOPMENTAL FACTORS, INFLAMMATIVE CYTOKINES, ENDOCRINE FACTORS AND METABOLIC MARKERS. VARIOUS LITERATURES ALSO SUPPORT THAT ENDOCRINE AND METABOLISM CHANGES ARE ASSOCIATED WITH MDD. ACCUMULATING EVIDENCE SUGGESTS THAT AT LEAST A PORTION OF MDD PATIENTS SHOW CHARACTERISTICS PATHOLOGICAL CHANGES REGARDING DIFFERENT CLINICAL PATHOLOGICAL BIOMARKERS. BY THIS REVIEW WE SUM UP ALL THE DIFFERENT BIOMARKERS PLAYING AN IMPORTANT ROLE IN THE DETECTION OR TREATMENT OF THE DIFFERENT PATIENTS SUFFERING FROM MDD. THE REVIEW ALSO GIVES AN OVERVIEW OF DIFFERENT BIOMARKER'S PLAYING A POTENTIAL ROLE IN MODULATING EFFECT OF MDD. 2021 10 5040 30 PHARMACOGENETICS OF PAIN AND ANALGESIA. PAIN SEVERITY RATINGS AND THE ANALGESIC DOSING REQUIREMENTS OF PATIENTS WITH APPARENTLY SIMILAR PAIN CONDITIONS MAY DIFFER CONSIDERABLY BETWEEN INDIVIDUALS. CONTRIBUTING FACTORS INCLUDE THOSE OF GENETIC AND ENVIRONMENTAL ORIGIN WITH EPIGENETIC MECHANISMS THAT ENABLE DYNAMIC GENE-ENVIRONMENT INTERACTION, MORE RECENTLY IMPLICATED IN PAIN MODULATION. INSIGHT INTO GENETIC FACTORS UNDERPINNING INTER-PATIENT VARIABILITY IN PAIN SENSITIVITY HAS COME FROM RODENT HERITABILITY STUDIES AS WELL AS FAMILIAL AGGREGATION AND TWIN STUDIES IN HUMANS. INDEED, MORE THAN 350 CANDIDATE PAIN GENES HAVE BEEN IDENTIFIED AS POTENTIALLY CONTRIBUTING TO HERITABLE DIFFERENCES IN PAIN SENSITIVITY. A LARGE NUMBER OF GENETIC ASSOCIATION STUDIES CONDUCTED IN PATIENTS WITH A VARIETY OF CLINICAL PAIN TYPES OR IN HUMANS EXPOSED TO EXPERIMENTALLY INDUCED PAIN STIMULI IN THE LABORATORY SETTING, HAVE EXAMINED THE IMPACT OF SINGLE-NUCLEOTIDE POLYMORPHISMS IN VARIOUS TARGET GENES ON PAIN SENSITIVITY AND/OR ANALGESIC DOSING REQUIREMENTS. HOWEVER, THE FINDINGS OF SUCH STUDIES HAVE GENERALLY FAILED TO REPLICATE OR HAVE BEEN ONLY PARTIALLY REPLICATED BY INDEPENDENT INVESTIGATORS. DEFICIENCIES IN STUDY CONDUCT INCLUDING USE OF SMALL SAMPLE SIZE, INAPPROPRIATE STATISTICAL METHODS AND INADEQUATE ATTENTION TO THE POSSIBILITY THAT BETWEEN-STUDY DIFFERENCES IN ENVIRONMENTAL FACTORS MAY ALTER PAIN PHENOTYPES THROUGH EPIGENETIC MECHANISMS, HAVE BEEN IDENTIFIED AS BEING SIGNIFICANT. 2012 11 2404 34 EPIGENETIC RESEARCH IN MULTIPLE SCLEROSIS: PROGRESS, CHALLENGES, AND OPPORTUNITIES. MULTIPLE SCLEROSIS (MS) IS A CHRONIC INFLAMMATORY AND DEMYELINATING DISEASE OF THE CENTRAL NERVOUS SYSTEM. MS LIKELY RESULTS FROM A COMPLEX INTERPLAY BETWEEN PREDISPOSING CAUSAL GENE VARIANTS (THE STRONGEST INFLUENCE COMING FROM HLA CLASS II LOCUS) AND ENVIRONMENTAL RISK FACTORS SUCH AS SMOKING, INFECTIOUS MONONUCLEOSIS, AND LACK OF SUN EXPOSURE/VITAMIN D. HOWEVER, LITTLE IS KNOWN ABOUT THE MECHANISMS UNDERLYING MS DEVELOPMENT AND PROGRESSION. MOREOVER, THE CLINICAL HETEROGENEITY AND VARIABLE RESPONSE TO TREATMENT REPRESENT ADDITIONAL CHALLENGES TO A COMPREHENSIVE UNDERSTANDING AND EFFICIENT TREATMENT OF DISEASE. EPIGENETIC PROCESSES, SUCH AS DNA METHYLATION AND HISTONE POSTTRANSLATIONAL MODIFICATIONS, INTEGRATE INFLUENCES FROM THE GENES AND THE ENVIRONMENT TO REGULATE GENE EXPRESSION ACCORDINGLY. STUDYING EPIGENETIC MODIFICATIONS, WHICH ARE STABLE AND REVERSIBLE, MAY PROVIDE AN ALTERNATIVE APPROACH TO BETTER UNDERSTAND AND MANAGE DISEASE. WE HERE AIM TO REVIEW FINDINGS FROM EPIGENETIC STUDIES IN MS AND FURTHER DISCUSS THE CHALLENGES AND CLINICAL OPPORTUNITIES ARISING FROM EPIGENETIC RESEARCH, MANY OF WHICH APPLY TO OTHER DISEASES WITH SIMILAR COMPLEX ETIOLOGY. A GROWING BODY OF EVIDENCE SUPPORTS A ROLE OF EPIGENETIC PROCESSES IN THE MECHANISMS UNDERLYING IMMUNE PATHOGENESIS AND NERVOUS SYSTEM DYSFUNCTION IN MS. HOWEVER, DISPARITIES BETWEEN STUDIES SHED LIGHT ON THE NEED TO CONSIDER POSSIBLE CONFOUNDERS AND METHODOLOGICAL LIMITATIONS FOR A BETTER INTERPRETATION OF THE DATA. NEVERTHELESS, TRANSLATIONAL USE OF EPIGENETICS MIGHT OFFER NEW OPPORTUNITIES IN EPIGENETIC-BASED DIAGNOSTICS AND THERAPEUTIC TOOLS FOR A PERSONALIZED CARE OF MS PATIENTS. 2017 12 5133 29 POTENTIAL EPIGENETIC MECHANISM(S) ASSOCIATED WITH THE PERSISTENCE OF PSYCHONEUROLOGICAL SYMPTOMS IN WOMEN RECEIVING CHEMOTHERAPY FOR BREAST CANCER: A HYPOTHESIS. DUE TO RECENT TREATMENT ADVANCES, THERE HAVE BEEN IMPROVEMENTS IN THE PROPORTION OF WOMEN SURVIVING A DIAGNOSIS OF BREAST CANCER (BC). HOWEVER, MANY OF THESE SURVIVORS REPORT PERSISTENT ADVERSE SIDE EFFECTS FOLLOWING TREATMENT, SUCH AS COGNITIVE DYSFUNCTION, DEPRESSIVE SYMPTOMS, ANXIETY, FATIGUE, SLEEP DISTURBANCES, AND PAIN. INVESTIGATORS HAVE EXAMINED CIRCULATING LEVELS OF INFLAMMATORY MARKERS, PARTICULARLY SERUM CYTOKINES, FOR A POTENTIAL CAUSAL RELATIONSHIP TO THE DEVELOPMENT/PERSISTENCE OF THESE PSYCHONEUROLOGICAL SYMPTOMS (PNS). WHILE INFLAMMATORY ACTIVATION, RESULTING FROM PERCEIVED STRESS OR OTHER FACTORS, MAY DIRECTLY CONTRIBUTE TO THE DEVELOPMENT OF PNS, WE OFFER AN ALTERNATIVE HYPOTHESIS, SUGGESTING THAT THESE SYMPTOMS ARE AN EARLY STEP IN A CASCADE OF BIOLOGICAL CHANGES LEADING TO EPIGENETIC ALTERATIONS AT THE LEVEL OF DEOXYRIBONUCLEIC ACID (DNA) METHYLATION, HISTONE MODIFICATIONS, AND/OR CHROMATIN STRUCTURE/CHROMOSOMAL INSTABILITY. GIVEN THAT EPIGENETIC PATTERNS HAVE PLASTICITY, IF THIS CONJECTURED RELATIONSHIP BETWEEN EPIGENOMIC/ACQUIRED GENOMIC ALTERATIONS AND THE DEVELOPMENT/PERSISTENCE OF PNS IS CONFIRMED, IT COULD PROVIDE FOUNDATIONAL KNOWLEDGE FOR FUTURE RESEARCH LEADING TO THE RECOGNITION OF PREDICTIVE MARKERS AND/OR TREATMENTS TO ALLEVIATE PNS IN WOMEN WITH BC. IN THIS ARTICLE, WE DISCUSS AN EVOLVING THEORY OF THE BIOLOGICAL BASIS OF PNS, INTEGRATING KNOWLEDGE RELATED TO INFLAMMATION AND DNA REPAIR IN THE CONTEXT OF GENETIC AND EPIGENETIC SCIENCE TO EXPAND THE PARADIGM FOR UNDERSTANDING SYMPTOM ACQUISITION/PERSISTENCE FOLLOWING CHEMOTHERAPY. 2014 13 2816 36 FIBROMYALGIA: PATHOGENESIS, MECHANISMS, DIAGNOSIS AND TREATMENT OPTIONS UPDATE. FIBROMYALGIA IS A SYNDROME CHARACTERIZED BY CHRONIC AND WIDESPREAD MUSCULOSKELETAL PAIN, OFTEN ACCOMPANIED BY OTHER SYMPTOMS, SUCH AS FATIGUE, INTESTINAL DISORDERS AND ALTERATIONS IN SLEEP AND MOOD. IT IS ESTIMATED THAT TWO TO EIGHT PERCENT OF THE WORLD POPULATION IS AFFECTED BY FIBROMYALGIA. FROM A MEDICAL POINT OF VIEW, THIS PATHOLOGY STILL PRESENTS INEXPLICABLE ASPECTS. IT IS KNOWN THAT FIBROMYALGIA IS CAUSED BY A CENTRAL SENSITIZATION PHENOMENON CHARACTERIZED BY THE DYSFUNCTION OF NEURO-CIRCUITS, WHICH INVOLVES THE PERCEPTION, TRANSMISSION AND PROCESSING OF AFFERENT NOCICEPTIVE STIMULI, WITH THE PREVALENT MANIFESTATION OF PAIN AT THE LEVEL OF THE LOCOMOTOR SYSTEM. IN RECENT YEARS, THE PATHOGENESIS OF FIBROMYALGIA HAS ALSO BEEN LINKED TO OTHER FACTORS, SUCH AS INFLAMMATORY, IMMUNE, ENDOCRINE, GENETIC AND PSYCHOSOCIAL FACTORS. A RHEUMATOLOGIST TYPICALLY MAKES A DIAGNOSIS OF FIBROMYALGIA WHEN THE PATIENT DESCRIBES A HISTORY OF PAIN SPREADING IN ALL QUADRANTS OF THE BODY FOR AT LEAST THREE MONTHS AND WHEN PAIN IS CAUSED BY DIGITAL PRESSURE IN AT LEAST 11 OUT OF 18 ALLOGENIC POINTS, CALLED TENDER POINTS. FIBROMYALGIA DOES NOT INVOLVE ORGANIC DAMAGE, AND SEVERAL DIAGNOSTIC APPROACHES HAVE BEEN DEVELOPED IN RECENT YEARS, INCLUDING THE ANALYSIS OF GENETIC, EPIGENETIC AND SEROLOGICAL BIOMARKERS. SYMPTOMS OFTEN BEGIN AFTER PHYSICAL OR EMOTIONAL TRAUMA, BUT IN MANY CASES, THERE APPEARS TO BE NO OBVIOUS TRIGGER. WOMEN ARE MORE PRONE TO DEVELOPING THE DISEASE THAN MEN. UNFORTUNATELY, THE CONVENTIONAL MEDICAL THERAPIES THAT TARGET THIS PATHOLOGY PRODUCE LIMITED BENEFITS. THEY REMAIN LARGELY PHARMACOLOGICAL IN NATURE AND TEND TO TREAT THE SYMPTOMATIC ASPECTS OF VARIOUS DISORDERS REPORTED BY THE PATIENT. THE STATISTICS, HOWEVER, HIGHLIGHT THE FACT THAT 90% OF PEOPLE WITH FIBROMYALGIA ALSO TURN TO COMPLEMENTARY MEDICINE TO MANAGE THEIR SYMPTOMS. 2021 14 2011 34 EPIGENETIC BASIS OF MENTAL ILLNESS. PSYCHIATRIC DISORDERS ARE COMPLEX MULTIFACTORIAL ILLNESSES INVOLVING CHRONIC ALTERATIONS IN NEURAL CIRCUIT STRUCTURE AND FUNCTION AS WELL AS LIKELY ABNORMALITIES IN GLIAL CELLS. WHILE GENETIC FACTORS ARE IMPORTANT IN THE ETIOLOGY OF MOST MENTAL DISORDERS, THE RELATIVELY HIGH RATES OF DISCORDANCE AMONG IDENTICAL TWINS, PARTICULARLY FOR DEPRESSION AND OTHER STRESS-RELATED SYNDROMES, CLEARLY INDICATE THE IMPORTANCE OF ADDITIONAL MECHANISMS. ENVIRONMENTAL FACTORS SUCH AS STRESS ARE KNOWN TO PLAY A ROLE IN THE ONSET OF THESE ILLNESSES. EXPOSURE TO SUCH ENVIRONMENTAL INSULTS INDUCES STABLE CHANGES IN GENE EXPRESSION, NEURAL CIRCUIT FUNCTION, AND ULTIMATELY BEHAVIOR, AND THESE MALADAPTATIONS APPEAR DISTINCT BETWEEN DEVELOPMENTAL VERSUS ADULT EXPOSURES. INCREASING EVIDENCE INDICATES THAT THESE SUSTAINED ABNORMALITIES ARE MAINTAINED BY EPIGENETIC MODIFICATIONS IN SPECIFIC BRAIN REGIONS. INDEED, TRANSCRIPTIONAL DYSREGULATION AND THE ABERRANT EPIGENETIC REGULATION THAT UNDERLIES THIS DYSREGULATION IS A UNIFYING THEME IN PSYCHIATRIC DISORDERS. HERE, WE PROVIDE A PROGRESS REPORT OF EPIGENETIC STUDIES OF THE THREE MAJOR PSYCHIATRIC SYNDROMES, DEPRESSION, SCHIZOPHRENIA, AND BIPOLAR DISORDER. WE REVIEW THE LITERATURE DERIVED FROM ANIMAL MODELS OF THESE DISORDERS AS WELL AS FROM STUDIES OF POSTMORTEM BRAIN TISSUE FROM HUMAN PATIENTS. WHILE EPIGENETIC STUDIES OF MENTAL ILLNESS REMAIN AT EARLY STAGES, UNDERSTANDING HOW ENVIRONMENTAL FACTORS RECRUIT THE EPIGENETIC MACHINERY WITHIN SPECIFIC BRAIN REGIONS TO CAUSE LASTING CHANGES IN DISEASE SUSCEPTIBILITY AND PATHOPHYSIOLOGY IS REVEALING NEW INSIGHT INTO THE ETIOLOGY AND TREATMENT OF THESE CONDITIONS. 2016 15 1329 31 DEPRESSION ASSOCIATED WITH DIABETES: FROM PATHOPHYSIOLOGY TO TREATMENT. DIABETES IS A CHRONIC AND PROGRESSIVE SYNDROME COMMONLY ASSOCIATED WITH SEVERAL NEUROPSYCHIATRIC COMORBITIES, OF WHICH DEPRESSION IS THE MOST STUDIED. THE PREVALENCE OF DEPRESSION IS ABOUT TWO OR THREE TIMES HIGHER IN DIABETIC PATIENTS COMPARED TO THE GENERAL POPULATION. IT IS BELIEVED THAT THE DIABETES - DEPRESSION RELATION MAY BE BIDIRECTIONAL, I.E., THE DEPRESSION CAN LEAD TO DIABETES AND CONVERSELY DIABETES COULD FACILITATE THE EMERGENCE OF DEPRESSION. DEPRESSION IS ONE OF THE MOST NEGLECTED SYMPTOMS IN DIABETIC PATIENTS AND IS DIRECTLY LINKED WITH LOWERING OF QUALITY OF LIFE. THE TREATMENT OF DEPRESSION IN THESE PATIENTS IS STILL QUITE INEFFECTIVE AND IN MANY CASES TREATMENTREFRACTORY. FURTHERMORE, SOME OF THE FIRST CHOICE DRUGS USED TO TREAT THE DEPRESSION AFFECT THE BLOOD GLUCOSE CONTROL, AGGRAVATING THE HYPERGLYCEMIC STATE. THESE ISSUES UNDERSCORE THE URGENCY IN STUDIES SEARCHING FOR NEW PHARMACOLOGICAL TARGETS FOR THE TREATMENT OF DEPRESSION ASSOCIATED WITH DIABETES. FOR THIS, A BETTER UNDERSTANDING OF THE PATHOPHYSIOLOGY THAT RELATES THIS COMORBIDITY BECOMES CRITICAL. IN THIS RESPECT, THIS REVIEW WILL FOCUS ON SOME HYPOTHESES THAT HAVE BEEN PROPOSED TO EXPLAIN THE MECHANISMS UNDERLYING DEPRESSION ASSOCIATED WITH DIABETES, HIGHLIGHTING THE TREATMENT OPTIONS CURRENTLY AVAILABLE AND THEIR LIMITATIONS. AMONG THESE HYPOTHESES, WE WILL POINT OUT THE HYPERGLYCEMIA AS A PRIMARY METABOLIC CAUSE OF THE DEPRESSION DEVELOPMENT, THE INVOLVEMENT OF THE DYSREGULATION OF HYPOTHALAMIC PITUITARY-ADRENAL (HPA) AXIS AND OF NEUROTRANSMITTER SYSTEMS, SPECIALLY MONOAMINERGIC SYSTEM. BESIDES, THE ROLE OF OXIDATIVE STRESS, NEUROINFLAMMATION AND CELL DEATH, ESPECIALLY IN HIPPOCAMPUS AND PREFRONTAL CORTEX, BRAIN AREAS IMPORTANT FOR THE MEDIATION AND MODULATION OF EMOTIONAL BEHAVIOR WILL ALSO BE DISCUSSED. FINALLY, WE WILL BRING UP THE INFLUENCE OF THE EPIGENETIC REGULATION WITH RESPECT TO NEUROPSYCHIATRIC DISORDERS. 2016 16 6791 26 [DOES THE NUMBER OF PATIENTS WITH AUTOIMMUNE DISORDERS AND THE FREQUENCY OF AUTOIMMUNE DISEASES INCREASE?]. AUTOIMMUNE DISEASES GENERALLY BELONG TO THE RARE DISEASES, HOWEVER, SOME OF THEM ARE FREQUENT IN THE POPULATION. IN THE PRESENT WORK THE AUTHORS ANALYSE WHETHER CAN ANY INCREASE BE OBSERVED IN THE NUMBER OF PATIENTS SUFFERING FROM AUTOIMMUNE DISEASES AND WHETHER DO THE FREQUENCY OF CERTAIN AUTOIMMUNE DISORDERS INCREASE. DUE MAINLY TO EPIGENETIC FACTORS THE INCIDENCE OF AUTOIMMUNE DISEASES ARE INCREASING, THEREFORE THERE ARE MORE PATIENTS RECOGNISED WITH PARTICULAR DISORDERS. ON THE OTHER HAND THE INCIDENCE IS INCREASED BY IMPROVING DIAGNOSTIC POSSIBILITIES, BY THE USE OF MORE SPECIFIC AND SENSITIVE CLASSIFICATION CRITERIA AND MORE SOPHISTICATED LABORATORY TESTS, RESULTED IN THE RECOGNITION OF MILDER AND ATYPICAL DISEASE VARIANTS AS WELL. THE PREVALENCE IS ALSO INCREASING IN CONSEQUENCE OF NOVEL IMMUNE SUPPRESSIVE THERAPEUTIC POSSIBILITIES AND THE CONSEQUENT IMPROVEMENT OF SURVIVAL IN THE MOST OF THESE DISEASES. BESIDES, MORE AND MORE DISEASES HAVE BEEN REVEALED TO HAVE AUTOIMMUNE BACKGROUND, AND LOT OF NEW AUTOIMMUNE SYNDROMES, DISEASES HAVE BEEN CHARACTERISED RECENTLY. THIS INCREASES THE NUMBER OF THE KNOWN AUTOIMMUNE RHEUMATIC DISORDERS WITH A CONSEQUENT INCREASE IN THE NUMBER OF AUTOIMMUNE PATIENTS. ASSIGNED TO THE INCREASING NUMBER OF VARIABLE CHRONIC AUTOIMMUNE DISORDERS, AND THE INCREASING NUMBER OF DISABLED PATIENTS WITH SUCH DISEASES INCREASING MEDICAL AND SOCIAL ATTENTION HAS TO BE FOCUSED ON. 2007 17 38 24 A COMMON ROLE FOR PSYCHOTROPIC MEDICATIONS: MEMORY IMPAIRMENT. THE PSYCHOPATHOLOGIC PROFILE OF MENTAL DISORDERS IS VERY DIVERSE AND PSYCHOTROPIC MEDICATIONS USED TO TREAT THEM DIFFER IN THEIR CHEMICAL STRUCTURE. NEVERTHELESS, THESE DRUGS SHARE THESE FOUR CHARACTERISTICS: DELAYED ONSET OF CLINICAL RESPONSE, NOT ONE OF THEM CAN BE SAID TO CURE, THERE IS A HIGH NUMBER OF NON-RESPONDERS, AND THE MECHANISM RESPONSIBLE FOR THEIR THERAPEUTIC ACTION IS NOT KNOWN. IT IS HYPOTHESIZED THAT THE ACTION OF PSYCHOTROPIC MEDICATIONS IS MEMORY IMPAIRMENT, UNDERSTANDING MEMORY AS THE TRACE LEFT IN THE NERVOUS SYSTEM NOT ONLY BY INDIVIDUAL EXPERIENCES BUT ALSO BY GENETIC AND EPIGENETIC PHENOMENA. IT IS SUGGESTED THAT IT WOULD BE BENEFICIAL TO TRANSLATE SOME RESEARCH STRATEGIES FROM THE NEUROBIOLOGY OF LEARNING AND MEMORY TO THE STUDY OF THE EFFECTS OF PSYCHOTROPIC MEDICATIONS. THE HYPOTHESIS IS BRIEFLY ASSESSED ACCORDING TO THE FOLLOWING THREE CRITERIA: (A). THE COMPARISON BETWEEN THE MOLECULAR EFFECTS OF PSYCHOTROPIC MEDICATIONS AND THE SO-CALLED MOLECULAR BIOLOGY OF LEARNING AND MEMORY, (B). THE EFFECTS OF THESE DRUGS, PREFERENTIALLY AFTER CHRONIC USE, ON MEMORY TESTS, AND (C). THE EFFECTS OF DRUGS THAT IMPAIR MEMORY ON TESTS USED FOR SCREENING PSYCHOTROPIC MEDICATIONS. FINALLY, SOME GENERAL SUGGESTIONS FOR FUTURE RESEARCH ARE POINTED OUT. 2003 18 3602 30 IMPRINTED GENES AND MULTIPLE SCLEROSIS: WHAT DO WE KNOW? MULTIPLE SCLEROSIS (MS) IS A CHRONIC AUTOIMMUNE NEURODEGENERATIVE DISEASE OF THE CENTRAL NERVOUS SYSTEM THAT ARISES FROM INTERPLAY BETWEEN NON-GENETIC AND GENETIC RISK FACTORS. THE EPIGENETICS FUNCTIONS AS A LINK BETWEEN THESE FACTORS, AFFECTING GENE EXPRESSION IN RESPONSE TO EXTERNAL INFLUENCE, AND THEREFORE SHOULD BE EXTENSIVELY STUDIED TO IMPROVE THE KNOWLEDGE OF MS MOLECULAR MECHANISMS. AMONG OTHERS, THE EPIGENETIC MECHANISMS UNDERLIE THE ESTABLISHMENT OF PARENT-OF-ORIGIN EFFECTS THAT APPEAR AS PHENOTYPIC DIFFERENCES DEPENDING ON WHETHER THE ALLELE WAS INHERITED FROM THE MOTHER OR FATHER. THE MOST WELL DESCRIBED MANIFESTATION OF PARENT-OF-ORIGIN EFFECTS IS GENOMIC IMPRINTING THAT CAUSES MONOALLELIC GENE EXPRESSION. IT BECOMES MORE OBVIOUS THAT DISTURBANCES IN IMPRINTED GENES AT THE LEAST AFFECTING THEIR EXPRESSION DO OCCUR IN MS AND MAY BE INVOLVED IN ITS PATHOGENESIS. IN THIS REVIEW WE WILL FOCUS ON THE POTENTIAL ROLE OF IMPRINTED GENES IN MS PATHOGENESIS. 2021 19 6866 28 [PAIN AND EMOTIONAL DYSREGULATION: CELLULAR MEMORY DUE TO PAIN]. GENETIC FACTORS ARE INVOLVED IN DETERMINANTS FOR THE RISK OF PSYCHIATRIC DISORDERS, AND NEUROLOGICAL AND NEURODEGENERATIVE DISEASES. CHRONIC PAIN STIMULI AND INTENSE PAIN HAVE EFFECTS AT A CELLULAR AND/OR GENE EXPRESSION LEVEL, AND WILL EVENTUALLY INDUCE "CELLULAR MEMORY DUE TO PAIN", WHICH MEANS THAT TISSUE DAMAGE, EVEN IF ONLY TRANSIENT, CAN ELICIT EPIGENETICALLY ABNORMAL TRANSCRIPTION/TRANSLATION AND POST-TRANSLATIONAL MODIFICATION IN RELATED CELLS DEPENDING ON THE DEGREE OR KIND OF INJURY OR ASSOCIATED CONDITIONS. SUCH CELL MEMORY/TRANSFORMATION DUE TO PAIN CAN CAUSE AN ABNORMALITY IN A FUNDAMENTAL INTRACELLULAR RESPONSE, SUCH AS A CHANGE IN THE THREE-DIMENSIONAL STRUCTURE OF DNA, TRANSCRIPTION, OR TRANSLATION. ON THE OTHER HAND, PAIN IS A MULTIDIMENSIONAL EXPERIENCE WITH SENSORY-DISCRIMINATIVE AND MOTIVATIONAL-AFFECTIVE COMPONENTS. RECENT HUMAN BRAIN IMAGING STUDIES HAVE EXAMINED DIFFERENCES IN ACTIVITY IN THE NUCLEUS ACCUMBENS BETWEEN CONTROLS AND PATIENTS WITH CHRONIC PAIN, AND HAVE REVEALED THAT THE NUCLEUS ACCUMBENS PLAYS A ROLE IN PREDICTING THE VALUE OF A NOXIOUS STIMULUS AND ITS OFFSET, AND IN THE CONSEQUENT CHANGES IN THE MOTIVATIONAL STATE. IN THIS REVIEW, WE PROVIDE A VERY BRIEF OVERVIEW OF A COMPREHENSIVE UNDERSTANDING OF CHRONIC PAIN ASSOCIATED WITH EMOTIONAL DYSREGULATION DUE TO TRANSCRIPTIONAL REGULATION, EPIGENETIC MODIFICATION AND MIRNA REGULATION. 2015 20 2526 30 EPIGENETICS APPLIED TO PSYCHIATRY: CLINICAL OPPORTUNITIES AND FUTURE CHALLENGES. PSYCHIATRIC DISORDERS ARE CLINICALLY HETEROGENEOUS AND DEBILITATING CHRONIC DISEASES RESULTING FROM A COMPLEX INTERPLAY BETWEEN GENE VARIANTS AND ENVIRONMENTAL FACTORS. EPIGENETIC PROCESSES, SUCH AS DNA METHYLATION AND HISTONE POSTTRANSLATIONAL MODIFICATIONS, INSTRUCT THE CELL/TISSUE TO CORRECTLY INTERPRET EXTERNAL SIGNALS AND ADJUST ITS FUNCTIONS ACCORDINGLY. GIVEN THAT EPIGENETIC MODIFICATIONS ARE SENSITIVE TO ENVIRONMENT, STABLE, AND REVERSIBLE, EPIGENETIC STUDIES IN PSYCHIATRY COULD REPRESENT A PROMISING APPROACH TO BETTER UNDERSTANDING AND TREATING DISEASE. IN THE PRESENT REVIEW, WE AIM TO DISCUSS THE CLINICAL OPPORTUNITIES AND CHALLENGES ARISING FROM THE EPIGENETIC RESEARCH IN PSYCHIATRY. USING SELECTED EXAMPLES, WE FIRST RECAPITULATE KEY FINDINGS SUPPORTING THE ROLE OF ADVERSE LIFE EVENTS, ALONE OR IN COMBINATION WITH GENETIC RISK, IN EPIGENETIC PROGRAMMING OF NEUROPSYCHIATRIC SYSTEMS. EPIGENETIC STUDIES FURTHER REPORT ENCOURAGING FINDINGS ABOUT THE USE OF METHYLATION CHANGES AS DIAGNOSTIC MARKERS OF DISEASE PHENOTYPE AND PREDICTIVE TOOLS OF PROGRESSION AND RESPONSE TO TREATMENT. THEN WE DISCUSS THE POTENTIAL OF USING TARGETED EPIGENETIC PHARMACOTHERAPY, COMBINED WITH PSYCHOSOCIAL INTERVENTIONS, FOR FUTURE PERSONALIZED MEDICINE FOR PATIENTS. FINALLY, WE REVIEW THE METHODOLOGICAL LIMITATIONS THAT COULD HINDER INTERPRETATION OF EPIGENETIC DATA IN PSYCHIATRY. THEY MAINLY ARISE FROM HETEROGENEITY AT THE INDIVIDUAL AND TISSUE LEVEL AND REQUIRE FUTURE STRATEGIES IN ORDER TO REINFORCE THE BIOLOGICAL RELEVANCE OF EPIGENETIC DATA AND ITS TRANSLATIONAL USE IN PSYCHIATRY. OVERALL, WE SUGGEST THAT EPIGENETICS COULD PROVIDE NEW INSIGHTS INTO A MORE COMPREHENSIVE INTERPRETATION OF MENTAL ILLNESS AND MIGHT EVENTUALLY IMPROVE THE NOSOLOGY, TREATMENT, AND PREVENTION OF PSYCHIATRIC DISORDERS. 2018