1 4525 95 MULTIFACTORIAL CAUSES OF PARANOID SCHIZOPHRENIA WITH AUDITORY-VISUAL HALLUCINATIONS IN A 31-YEAR-OLD MALE WITH HISTORY OF TRAUMATIC BRAIN INJURY AND SUBSTANCE ABUSE. SCHIZOPHRENIA IS A CHRONIC PSYCHIATRIC DISORDER THAT CLASSICALLY PRESENTS WITH DISTORTIONS OF THOUGHT, BEHAVIOR, AND PERCEPTIONS THAT ARE OFTEN MISDIAGNOSED. ONE DIFFICULTY IN DIAGNOSING SCHIZOPHRENIA IS DUE TO ITS PHENOTYPICALLY HETEROGENEOUS CONDITION THAT CAN BE PRECIPITATED BY A COMBINATION OF GENETIC, EPIGENETIC, AND ENVIRONMENTAL FACTORS. THE PREVALENCE OF SCHIZOPHRENIA IS ROUGHLY 1%, BUT IT IS OFTEN MISDIAGNOSED. POSSIBLE DIFFERENTIAL DIAGNOSES INCLUDE DEPRESSION OR BIPOLAR DISORDER WITH PSYCHOSIS, PSYCHOSIS DUE TO A MEDICAL CONDITION, SCHIZOTYPAL AND SCHIZOID PERSONALITY DISORDERS, AND NEUROCOGNITIVE DISORDERS. IN THIS CASE REPORT, A 31-YEAR-OLD MALE PRESENTS WITH THOUGHTS OF SUICIDE FOLLOWING A RECENT EXACERBATION OF HIS HALLUCINATIONS. ON PRESENTATION, THE PATIENT PRESENTED WITH A HISTORICAL DIAGNOSIS OF "PARANOID SCHIZOPHRENIA" AS WELL AS A HISTORY OF TRAUMATIC BRAIN INJURY (TBI), POLY-SUBSTANCE USE DISORDER, AND A FAMILY HISTORY OF SCHIZOPHRENIA. THIS CASE SERVES TO HIGHLIGHT THE DIFFICULTIES OF MAKING AN ACCURATE DIAGNOSIS AND PROVIDING EVIDENCED-BASED TREATMENT. 2022 2 4390 28 MODELING THE MOLECULAR EPIGENETIC PROFILE OF PSYCHOSIS IN PRENATALLY STRESSED MICE. BASED ON POSTMORTEM BRAIN STUDIES, OUR OVERARCHING EPIGENETIC HYPOTHESIS IS THAT CHRONIC SCHIZOPHRENIA (SZ) IS A PSYCHOPATHOLOGICAL CONDITION INVOLVING DYSREGULATION OF THE DYNAMIC EQUILIBRIUM AMONG DNA METHYLATION/DEMETHYLATION NETWORK COMPONENTS AND THE EXPRESSION OF SZ TARGET GENES, INCLUDING GABAERGIC AND GLUTAMATERGIC GENES. SZ HAS A NATURAL COURSE, STARTING WITH A PRODROMAL PHASE, A FIRST EPISODE THAT OCCURS IN ADOLESCENTS OR IN YOUNG ADULTS, AND LATER DETERIORATION OVER THE ADULT YEARS. HENCE, THE EPIGENETIC STATUS AT EACH NEURODEVELOPMENTAL STAGE OF THE DISEASE CANNOT BE STUDIED JUST IN POSTMORTEM BRAIN OF CHRONIC SZ PATIENTS, BUT REQUIRES THE USE OF NEURODEVELOPMENTAL ANIMAL MODELS. WE HAVE DIRECTED THE FOCUS OF OUR RESEARCH TOWARD STUDYING THE EPIGENETIC SIGNATURE OF THE SZ BRAIN IN THE OFFSPRING OF DAMS STRESSED DURING PREGNANCY (PRS MICE). ADULT PRS MICE HAVE BEHAVIORAL DEFICITS REMINISCENT OF BEHAVIORS OBSERVED IN PSYCHOTIC PATIENTS. THE ADULT PRS BRAIN, LIKE THAT OF POSTMORTEM CHRONIC SZ PATIENTS, IS CHARACTERIZED BY A SIGNIFICANT INCREASE IN DNA METHYLTRANSFERASE 1, TET METHYLCYTOSINE DIOXYGENASE 1 (TET1), 5-METHYLCYTOSINE, AND 5-HYDROXYMETHYLCYTOSINE AT SZ CANDIDATE GENE PROMOTERS AND A REDUCTION IN THE EXPRESSION OF GLUTAMATERGIC AND GABAERGIC GENES. IN PRS MICE, MEASUREMENTS OF EPIGENETIC BIOMARKERS FOR SZ CAN BE ASSESSED AT DIFFERENT STAGES OF DEVELOPMENT WITH THE GOAL OF FURTHER ELUCIDATING THE PATHOPHYSIOLOGY OF THIS DISEASE AND PREDICTING TREATMENT RESPONSES AT SPECIFIC STAGES OF THE ILLNESS, WITH PARTICULAR ATTENTION TO EARLY DETECTION AND POSSIBLY EARLY INTERVENTION. 2014 3 6266 20 THE NEUROBIOLOGY OF SUICIDE. THE STRESS-DIATHESIS MODEL POSITS THAT SUICIDE IS THE RESULT OF AN INTERACTION BETWEEN STATE-DEPENDENT (ENVIRONMENTAL) STRESSORS AND A TRAIT-LIKE DIATHESIS OR SUSCEPTIBILITY TO SUICIDAL BEHAVIOUR, INDEPENDENT OF PSYCHIATRIC DISORDERS. FINDINGS FROM POST-MORTEM STUDIES OF THE BRAIN AND FROM GENOMIC AND IN-VIVO NEUROIMAGING STUDIES INDICATE A BIOLOGICAL BASIS FOR THIS DIATHESIS, INDICATING THE IMPORTANCE OF NEUROBIOLOGICAL SCREENING AND INTERVENTIONS, IN ADDITION TO COGNITIVE AND MOOD INTERVENTIONS, IN THE PREVENTION OF SUICIDE. EARLY-LIFE ADVERSITY AND EPIGENETIC MECHANISMS MIGHT EXPLAIN SOME OF THE LINK BETWEEN SUICIDE RISK AND BRAIN CIRCUITRY AND NEUROCHEMISTRY ABNORMALITIES. RESULTS FROM A RANGE OF STUDIES USING DIVERSE DESIGNS AND POST-MORTEM AND IN-VIVO TECHNIQUES SHOW IMPAIRMENTS OF THE SEROTONIN NEUROTRANSMITTER SYSTEM AND THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS STRESS-RESPONSE SYSTEM IN THE DIATHESIS FOR SUICIDAL BEHAVIOUR. THESE IMPAIRMENTS MANIFEST AS IMPAIRED COGNITIVE CONTROL OF MOOD, PESSIMISM, REACTIVE AGGRESSIVE TRAITS, IMPAIRED PROBLEM SOLVING, OVER-REACTIVITY TO NEGATIVE SOCIAL SIGNS, EXCESSIVE EMOTIONAL PAIN, AND SUICIDAL IDEATION, LEADING TO SUICIDAL BEHAVIOUR. BIOMARKERS RELATED TO THE DIATHESIS MIGHT HELP TO INFORM RISK-ASSESSMENT PROCEDURES AND TREATMENT CHOICE IN THE PREVENTION OF SUICIDE. 2014 4 4623 29 NEUROBIOLOGY OF BIPOLAR DISORDERS: A REVIEW OF GENETIC COMPONENTS, SIGNALING PATHWAYS, BIOCHEMICAL CHANGES, AND NEUROIMAGING FINDINGS. BIPOLAR DISORDER (BD) IS A CHRONIC MENTAL ILLNESS CHARACTERIZED BY CHANGES IN MOOD THAT ALTERNATE BETWEEN MANIA AND HYPOMANIA OR BETWEEN DEPRESSION AND MIXED STATES, OFTEN ASSOCIATED WITH FUNCTIONAL IMPAIRMENT. ALTHOUGH EFFECTIVE PHARMACOLOGICAL AND NON-PHARMACOLOGICAL TREATMENTS ARE AVAILABLE, SEVERAL PATIENTS WITH BD REMAIN SYMPTOMATIC. THE ADVANCE IN THE UNDERSTANDING OF THE NEUROBIOLOGY UNDERLYING BD COULD HELP IN THE IDENTIFICATION OF NEW THERAPEUTIC TARGETS AS WELL AS BIOMARKERS FOR EARLY DETECTION, PROGNOSIS, AND RESPONSE TO TREATMENT IN BD. IN THIS REVIEW, WE DISCUSS GENETIC, EPIGENETIC, MOLECULAR, PHYSIOLOGICAL AND NEUROIMAGING FINDINGS ASSOCIATED WITH THE NEUROBIOLOGY OF BD. DESPITE THE ADVANCES IN THE PATHOPHYSIOLOGICAL KNOWLEDGE OF BD, THE DIAGNOSIS AND MANAGEMENT OF THE DISEASE ARE STILL ESSENTIALLY CLINICAL. GIVEN THE COMPLEXITY OF THE BRAIN AND THE CLOSE RELATIONSHIP BETWEEN ENVIRONMENTAL EXPOSURE AND BRAIN FUNCTION, INITIATIVES THAT INCORPORATE GENETIC, EPIGENETIC, MOLECULAR, PHYSIOLOGICAL, CLINICAL, ENVIRONMENTAL DATA, AND BRAIN IMAGING ARE NECESSARY TO PRODUCE INFORMATION THAT CAN BE TRANSLATED INTO PREVENTION AND BETTER OUTCOMES FOR PATIENTS WITH BD. 2020 5 4328 28 MICRORNAS, STEM CELLS IN BIPOLAR DISORDER, AND LITHIUM THERAPEUTIC APPROACH. BIPOLAR DISORDER (BD) IS A SEVERE, CHRONIC, AND DISABLING NEUROPSYCHIATRIC DISORDER CHARACTERIZED BY RECURRENT MOOD DISTURBANCES (MANIA/HYPOMANIA AND DEPRESSION, WITH OR WITHOUT MIXED FEATURES) AND A CONSTELLATION OF COGNITIVE, PSYCHOMOTOR, AUTONOMIC, AND ENDOCRINE ABNORMALITIES. THE ETIOLOGY OF BD IS MULTIFACTORIAL, INCLUDING BOTH BIOLOGICAL AND EPIGENETIC FACTORS. RECENTLY, MICRORNAS (MIRNAS), A CLASS OF EPIGENETIC REGULATORS OF GENE EXPRESSION PLAYING A CENTRAL ROLE IN BRAIN DEVELOPMENT AND PLASTICITY, HAVE BEEN RELATED TO SEVERAL NEUROPSYCHIATRIC DISORDERS, INCLUDING BD. MOREOVER, AN ALTERATION IN THE NUMBER/DISTRIBUTION AND DIFFERENTIATION POTENTIAL OF NEURAL STEM CELLS HAS ALSO BEEN DESCRIBED, SIGNIFICANTLY AFFECTING BRAIN HOMEOSTASIS AND NEUROPLASTICITY. THIS REVIEW AIMED TO EVALUATE THE MOST RELIABLE SCIENTIFIC EVIDENCE ON MIRNAS AS BIOMARKERS FOR THE DIAGNOSIS OF BD AND ASSESS THEIR IMPLICATIONS IN RESPONSE TO MOOD STABILIZERS, SUCH AS LITHIUM. NEURAL STEM CELL DISTRIBUTION, REGULATION, AND DYSFUNCTION IN THE ETIOLOGY OF BD ARE ALSO DISSECTED. 2022 6 1734 25 EAAT2 AS A RESEARCH TARGET IN BIPOLAR DISORDER AND UNIPOLAR DEPRESSION: A SYSTEMATIC REVIEW. GLUTAMATE IS IMPLICATED IN THE NEUROPATHOLOGY OF BOTH MAJOR DEPRESSIVE DISORDER AND BIPOLAR DISORDER. EXCITATORY AMINO ACID TRANSPORTER 2 (EAAT2) IS THE MAJOR GLUTAMATE TRANSPORTER IN THE MAMMALIAN BRAIN, REMOVING GLUTAMATE FROM THE SYNAPTIC CLEFT AND TRANSPORTING IT INTO GLIA FOR RECYCLING. IT IS THEREBY THE PRINCIPAL REGULATOR OF EXTRACELLULAR GLUTAMATE LEVELS AND PREVENTS NEURONAL EXCITOTOXICITY. EAAT2 IS A PROMISING TARGET FOR ELUCIDATING THE MECHANISMS BY WHICH THE GLUTAMATE-GLUTAMINE CYCLE INTERACTS WITH NEURONAL SYSTEMS IN MOOD DISORDERS. FORTY EAAT2 STUDIES (PUBLISHED JANUARY 1992-JANUARY 2018) WERE IDENTIFIED VIA A SYSTEMATIC LITERATURE SEARCH. THE STUDIES DEMONSTRATED THAT CHRONIC STRESS/STEROIDS WERE MOST COMMONLY ASSOCIATED WITH DECREASED EAAT2. IN RODENTS, EAAT2 INHIBITION WORSENED DEPRESSIVE BEHAVIORS. HUMAN EAAT2 EXPRESSION USUALLY DECREASED IN DEPRESSION, WITH SOME REGIONAL BRAIN DIFFERENCES. FEWER DATA HAVE BEEN COLLECTED REGARDING THE ROLES AND REGULATION OF EAAT2 IN BIPOLAR DISORDER. FUTURE DIRECTIONS FOR RESEARCH INCLUDE CORRELATING EAAT2 AND GLUTAMATE LEVELS IN VIVO, ELUCIDATING GENETIC VARIABILITY AND EPIGENETIC REGULATION, CLARIFYING INTRACELLULAR PROTEIN AND PHARMACOLOGIC INTERACTIONS, AND EXAMINING EAAT2 IN DIFFERENT BIPOLAR MOOD STATES. AS PART OF A MACROMOLECULAR COMPLEX WITHIN GLIA, EAAT2 MAY CONTRIBUTE SIGNIFICANTLY TO INTRACELLULAR SIGNALING, ENERGY REGULATION, AND CELLULAR HOMEOSTASIS. AN ENHANCED UNDERSTANDING OF THIS SYSTEM IS NEEDED. 2020 7 579 26 BEHAVIORAL AND MOLECULAR NEUROEPIGENETIC ALTERATIONS IN PRENATALLY STRESSED MICE: RELEVANCE FOR THE STUDY OF CHROMATIN REMODELING PROPERTIES OF ANTIPSYCHOTIC DRUGS. WE HAVE RECENTLY REPORTED THAT MICE BORN FROM DAMS STRESSED DURING PREGNANCY (PRS MICE), IN ADULTHOOD, HAVE BEHAVIORAL DEFICITS REMINISCENT OF BEHAVIORS OBSERVED IN SCHIZOPHRENIA (SZ) AND BIPOLAR (BP) DISORDER PATIENTS. FURTHERMORE, WE HAVE SHOWN THAT THE FRONTAL CORTEX (FC) AND HIPPOCAMPUS OF ADULT PRS MICE, LIKE THAT OF POSTMORTEM CHRONIC SZ PATIENTS, ARE CHARACTERIZED BY INCREASES IN DNA-METHYLTRANSFERASE 1 (DNMT1), TEN-ELEVEN METHYLCYTOSINE DIOXYGENASE 1 (TET1) AND EXHIBIT AN ENRICHMENT OF 5-METHYLCYTOSINE (5MC) AND 5-HYDROXYMETHYLCYTOSINE (5HMC) AT NEOCORTICAL GABAERGIC AND GLUTAMATERGIC GENE PROMOTERS. HERE, WE SHOW THAT THE BEHAVIORAL DEFICITS AND THE INCREASED 5MC AND 5HMC AT GLUTAMIC ACID DECARBOXYLASE 67 (GAD1), REELIN (RELN) AND BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) PROMOTERS AND THE REDUCED EXPRESSION OF THE MESSENGER RNAS (MRNAS) AND PROTEINS CORRESPONDING TO THESE GENES IN FC OF ADULT PRS MICE IS REVERSED BY TREATMENT WITH CLOZAPINE (5 MG KG(-1) TWICE A DAY FOR 5 DAYS) BUT NOT BY HALOPERIDOL (1 MG KG(-1) TWICE A DAY FOR 5 DAYS). INTERESTINGLY, CLOZAPINE HAD NO EFFECT ON EITHER THE BEHAVIOR, PROMOTER METHYLATION OR THE EXPRESSION OF THESE MRNAS AND PROTEINS WHEN ADMINISTERED TO OFFSPRING OF NONSTRESSED PREGNANT MICE. CLOZAPINE, BUT NOT HALOPERIDOL, REDUCED THE ELEVATED LEVELS OF DNMT1 AND TET1, AS WELL AS THE ELEVATED LEVELS OF DNMT1 BINDING TO GAD1, RELN AND BDNF PROMOTERS IN PRS MICE SUGGESTING THAT CLOZAPINE, UNLIKE HALOPERIDOL, MAY LIMIT DNA METHYLATION BY INTERFERING WITH DNA METHYLATION DYNAMICS. WE CONCLUDE THAT THE PRS MOUSE MODEL MAY BE USEFUL PRECLINICALLY IN SCREENING FOR THE POTENTIAL EFFICACY OF ANTIPSYCHOTIC DRUGS ACTING ON ALTERED EPIGENETIC MECHANISMS. FURTHERMORE, PRS MICE MAY BE INVALUABLE FOR UNDERSTANDING THE ETIOPATHOGENESIS OF SZ AND BP DISORDER AND FOR PREDICTING TREATMENT RESPONSES AT EARLY STAGES OF THE ILLNESS ALLOWING FOR EARLY DETECTION AND REMEDIAL INTERVENTION. 2016 8 6329 28 THE ROLE OF CHILDHOOD TRAUMA IN BIPOLAR DISORDERS. THIS REVIEW WILL DISCUSS THE ROLE OF CHILDHOOD TRAUMA IN BIPOLAR DISORDERS. RELEVANT STUDIES WERE IDENTIFIED VIA MEDLINE (PUBMED) AND PSYCINFO DATABASES PUBLISHED UP TO AND INCLUDING JULY 2015. THIS REVIEW CONTRIBUTES TO A NEW UNDERSTANDING OF THE NEGATIVE CONSEQUENCES OF EARLY LIFE STRESS, AS WELL AS SETTING CHILDHOOD TRAUMA IN A BIOLOGICAL CONTEXT OF SUSCEPTIBILITY AND DISCUSSING NOVEL LONG-TERM PATHOPHYSIOLOGICAL CONSEQUENCES IN BIPOLAR DISORDERS. CHILDHOOD TRAUMATIC EVENTS ARE RISK FACTORS FOR DEVELOPING BIPOLAR DISORDERS, IN ADDITION TO A MORE SEVERE CLINICAL PRESENTATION OVER TIME (PRIMARILY AN EARLIER AGE AT ONSET AND AN INCREASED RISK OF SUICIDE ATTEMPT AND SUBSTANCE MISUSE). CHILDHOOD TRAUMA LEADS TO ALTERATIONS OF AFFECT REGULATION, IMPULSE CONTROL, AND COGNITIVE FUNCTIONING THAT MIGHT DECREASE THE ABILITY TO COPE WITH LATER STRESSORS. CHILDHOOD TRAUMA INTERACTS WITH SEVERAL GENES BELONGING TO SEVERAL DIFFERENT BIOLOGICAL PATHWAYS [HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS, SEROTONERGIC TRANSMISSION, NEUROPLASTICITY, IMMUNITY, CALCIUM SIGNALING, AND CIRCADIAN RHYTHMS] TO DECREASE THE AGE AT THE ONSET OF THE DISORDER OR INCREASE THE RISK OF SUICIDE. EPIGENETIC FACTORS MAY ALSO BE INVOLVED IN THE NEUROBIOLOGICAL CONSEQUENCES OF CHILDHOOD TRAUMA IN BIPOLAR DISORDER. BIOLOGICAL SEQUELAE SUCH AS CHRONIC INFLAMMATION, SLEEP DISTURBANCE, OR TELOMERE SHORTENING ARE POTENTIAL MEDIATORS OF THE NEGATIVE EFFECTS OF CHILDHOOD TRAUMA IN BIPOLAR DISORDERS, IN PARTICULAR WITH REGARD TO PHYSICAL HEALTH. THE MAIN CLINICAL IMPLICATION IS TO SYSTEMATICALLY ASSESS CHILDHOOD TRAUMA IN PATIENTS WITH BIPOLAR DISORDERS, OR AT LEAST IN THOSE WITH A SEVERE OR INSTABLE COURSE. THE CHALLENGE FOR THE NEXT YEARS WILL BE TO FILL THE GAP BETWEEN CLINICAL AND FUNDAMENTAL RESEARCH AND ROUTINE PRACTICE, SINCE RECOMMENDATIONS FOR MANAGING THIS SPECIFIC POPULATION ARE LACKING. IN PARTICULAR, LITTLE IS KNOWN ON WHICH PSYCHOTHERAPIES SHOULD BE PROVIDED OR WHICH TARGETS THERAPISTS SHOULD FOCUS ON, AS WELL AS HOW CHILDHOOD TRAUMA COULD EXPLAIN THE RESISTANCE TO MOOD STABILIZERS. 2016 9 1179 23 CONVERGENCE AND DIVERGENCE IN THE ETIOLOGY OF MYELIN IMPAIRMENT IN PSYCHIATRIC DISORDERS AND DRUG ADDICTION. IMPAIRMENT OF OLIGODENDROGLIA (OL)-DEPENDENT MYELINATION IN THE CENTRAL NERVOUS SYSTEM (CNS) IS A REMARKABLE PARALLEL RECENTLY IDENTIFIED IN MAJOR PSYCHIATRIC DISORDERS AND CHRONIC DRUG ABUSE. NEUROIMAGING AND NEUROPATHOLOGICAL STUDIES REVEALED MYELIN DEFECTS AND MICROARRAY-PROFILING ANALYSIS DEMONSTRATED ABERRANT EXPRESSION OF MYELIN-RELATED GENES IN SCHIZOPHRENIA (SZ), BIPOLAR DISORDER (BD), MAJOR DEPRESSIVE DISORDER (MDD) AND COCAINE ADDICTION. HOWEVER, THE ETIOLOGY UNDERLYING MYELIN IMPAIRMENT IN THESE CLINICALLY DISTINCT SUBJECTS REMAINS ELUSIVE. THIS ARTICLE REVIEWS MYELIN IMPAIRMENT IN LINE WITH DOPAMINERGIC DYSFUNCTION, A PRIME NEUROPATHOPHYSIOLOGICAL TRAIT SHARED IN PSYCHIATRIC DISORDERS AND DRUG ABUSE, AS WELL AS THE GENETIC AND EPIGENETIC ALTERATIONS ASSOCIATED WITH THESE DISEASES. THE CURRENT FINDINGS SUPPORT THE HYPOTHESIS THAT ABERRANT DOPAMINE (DA) ACTION ON OLS IS A COMMON PATHOLOGIC MECHANISM FOR MYELIN IMPAIRMENT IN THE AFOREMENTIONED MENTAL MORBIDITIES, WHEREAS INHERITED GENETIC VARIATIONS THAT SPECIFICALLY AFFECT OL DEVELOPMENT AND MYELINOGENESIS MAY FURTHER INCREASE MYELIN VULNERABILITY IN PSYCHIATRIC DISORDERS. IMPORTANTLY, OL DEFECT IS NOT ONLY A PATHOLOGICAL CONSEQUENCE BUT ALSO A CAUSATIVE FACTOR FOR DOPAMINERGIC DYSFUNCTION. HENCE, MYELIN IMPAIRMENT IS A KEY FACTOR IN THE PATHOGENIC LOOP OF PSYCHIATRIC DISEASES AND DRUG ADDICTION. 2008 10 5792 34 STAGING IN BIPOLAR DISORDER: FROM THEORETICAL FRAMEWORK TO CLINICAL UTILITY. ILLNESS STAGING IS WIDELY UTILIZED IN SEVERAL MEDICAL DISCIPLINES TO HELP PREDICT COURSE OR PROGNOSIS, AND OPTIMIZE TREATMENT. STAGING MODELS IN PSYCHIATRY IN GENERAL, AND BIPOLAR DISORDER IN PARTICULAR, DEPEND ON THE PREMISE THAT PSYCHOPATHOLOGY MOVES ALONG A PREDICTABLE PATH: AN AT-RISK OR LATENCY STAGE, A PRODROME PROGRESSING TO A FIRST CLINICAL THRESHOLD EPISODE, AND ONE OR MORE RECURRENCES WITH THE POTENTIAL TO REVERT OR PROGRESS TO LATE OR END-STAGE MANIFESTATIONS. THE UTILITY AND VALIDITY OF A STAGING MODEL FOR BIPOLAR DISORDER DEPEND ON ITS LINKING TO CLINICAL OUTCOME, TREATMENT RESPONSE AND NEUROBIOLOGICAL MEASURES. THESE INCLUDE PROGRESSIVE BIOCHEMICAL, NEUROIMAGING AND COGNITIVE CHANGES, AND POTENTIALLY STAGE-SPECIFIC DIFFERENCES IN RESPONSE TO PHARMACOLOGICAL AND PSYCHOSOCIAL TREATMENTS. MECHANISTICALLY, STAGING MODELS IMPLY THE PRESENCE OF AN ACTIVE DISEASE PROCESS THAT, IF NOT REMEDIATED, CAN LEAD TO NEUROPROGRESSION, A MORE MALIGNANT DISEASE COURSE AND FUNCTIONAL DETERIORATION. BIOLOGICAL ELEMENTS THOUGHT TO BE OPERATIVE IN BIPOLAR DISORDER INCLUDE A GENETIC DIATHESIS, PHYSICAL AND PSYCHIC TRAUMA, EPIGENETIC CHANGES, ALTERED NEUROGENESIS AND APOPTOSIS, MITOCHONDRIAL DYSFUNCTION, INFLAMMATION, AND OXIDATIVE STRESS. MANY AVAILABLE AGENTS, SUCH AS LITHIUM, HAVE EFFECTS ON THESE TARGETS. STAGING MODELS ALSO SUGGEST THE UTILITY OF STAGE-SPECIFIC TREATMENT APPROACHES THAT MAY NOT ONLY TARGET SYMPTOM REDUCTION, BUT ALSO IMPEDE ILLNESS NEUROPROGRESSION. THESE TREATMENT APPROACHES RANGE FROM PREVENTION FOR AT-RISK INDIVIDUALS, TO EARLY INTERVENTION STRATEGIES FOR PRODROMAL AND NEWLY DIAGNOSED INDIVIDUALS, COMPLEX COMBINATION THERAPY FOR RAPIDLY RECURRENT ILLNESS, AND PALLIATIVE-TYPE APPROACHES FOR THOSE AT CHRONIC, LATE STAGES OF ILLNESS. THERE IS HOPE THAT PROMPT INITIATION OF POTENTIALLY DISEASE MODIFYING THERAPIES MAY PRECLUDE OR ATTENUATE THE COGNITIVE AND STRUCTURAL CHANGES SEEN IN THE LATER STAGES OF BIPOLAR DISORDER. THE AIMS OF THIS PAPER ARE TO: A) EXPLORE THE CURRENT LEVEL OF EVIDENCE SUPPORTING THE DESCRIPTIVE STAGING OF THE SYNDROMAL PATTERN OF BIPOLAR DISORDER; B) DESCRIBE PRELIMINARY ATTEMPTS AT VALIDATION; C) MAKE RECOMMENDATIONS FOR THE DIRECTION OF FURTHER STUDIES; AND D) PROVIDE A DISTILLATION OF THE POTENTIAL CLINICAL IMPLICATIONS OF STAGING IN BIPOLAR DISORDER WITHIN A BROADER TRANSDIAGNOSTIC FRAMEWORK. 2017 11 1810 20 EFFECTS OF ANTIPSYCHOTICS ON THE BDNF IN SCHIZOPHRENIA. BRAIN-DERIVED NEUROTROPIC FACTOR (BDNF) IS INVOLVED IN THE DEVELOPMENT OF THE BRAIN, AND LIKELY INFLUENCES THE NEUROPLASTICITY IN SCHIZOPHRENIA. BDNF IS ALSO BELIEVED TO INTERACT WITH OTHER NEUROTRANSMITTER SYSTEMS IMPLICATED IN SCHIZOPHRENIA, SUCH AS DOPAMINE, GLUTAMATE, SEROTONIN AND GABA. THEREFORE, BDNF IS A CANDIDATE GENE FOR SCHIZOPHRENIA. IN PAST DECADES, THE BLOOD (SERUM OR PLASMA) BDNF PROTEIN LEVELS AND BDNF GENE ALLELES AND GENOTYPES TO THE CLINICAL FEATURES OF SCHIZOPHRENIA, SUCH AS AGE OF ONSET, CLINICAL SUBTYPES, SYMPTOM SEVERITY, AND DRUG RESPONSE, HAVE BEEN EVALUATED AMONG DIFFERENT POPULATIONS. HOWEVER, THE RESULTS ARE STILL INCONSISTENT. FURTHER, DIFFERENT DRUGS HAVE BEEN REPORTED TO HAVE DIFFERENT EFFECTS ON BDNF PROTEIN LEVELS. A CROSS-SECTIONAL SURVEY REVEALED THAT SERUM BDNF LEVELS IN CHRONIC SCHIZOPHRENIC PATIENTS TREATED WITH CLOZAPINE EXCEEDED THOSE OF PATIENTS TREATED WITH RISPERIDONE OR WITH TYPICAL ANTIPSYCHOTICS. IN RECENT TIMES, BDNF EPIGENETIC STUDIES HAVE ALSO BEEN CONDUCTED IN CLINICAL STUDIES OF SCHIZOPHRENIA TO ADDRESS THE QUESTION OF WHY PATIENTS WITH THE SAME GENE GENOTYPE AND ALLELES HAVE DIFFERENT CLINICAL PRESENTATIONS. IN ADDITION, THE EFFECTS OF DIFFERENT ANTIPSYCHOTIC DRUGS ON GENE METHYLATION AND PROTEIN ACETYLATION HAVE ALSO BEEN REPORTED. IN CONCLUSION, MORE DATA ARE NEEDED REGARDING BDNF IN THE BRAIN AND IN PERIPHERAL BLOOD, INCLUDING PROTEIN LEVELS, SINGLE NUCLEOTIDE POLYMORPHISMS, EPIGENETIC REGULATION, AND CLINICAL DATA IN ORDER TO UNDERSTAND THE ROLE OF BDNF IN SCHIZOPHRENIA. 2013 12 1538 24 DNA METHYLATION IN ANIMAL MODELS OF PSYCHOSIS. SCHIZOPHRENIA (SZ) IS A DEBILITATING DISEASE THAT IMPACTS 1% OF THE POPULATION WORLDWIDE. ASSOCIATION STUDIES HAVE SHOWN THAT INHERITED GENETIC MUTATIONS ACCOUNT FOR A PORTION OF DISEASE RISK. HOWEVER, ENVIRONMENTAL FACTORS PLAY AN IMPORTANT ROLE IN THE PATHOPHYSIOLOGY OF THE DISEASE BY ALTERING CELLULAR EPIGENETIC MARKS AT THE LEVEL OF CHROMATIN. POSTMORTEM BRAIN STUDIES OF SZ SUBJECTS SUGGEST THAT THE DYNAMIC EQUILIBRIUM BETWEEN DNA METHYLATION AND DEMETHYLATION NETWORK COMPONENTS IS DISRUPTED AT THE LEVEL OF INDIVIDUAL SZ TARGET GENES. HEREIN, WE REVIEW THE ROLE OF DNA METHYLATION AND DEMETHYLATION IN THE CONTEXT OF WHAT IS CURRENTLY KNOWN REGARDING SZ. FURTHERMORE, WE DESCRIBE THE DEFICITS THAT ACCOMPANY TWO MOUSE MODELS OF SZ. THE CHRONIC METHIONINE MOUSE MODEL OF SZ IS PREDICATED ON THE ADMINISTRATION OF METHIONINE TO SZ PATIENTS AND CONTROLS IN THE CONTEXT OF CLINICAL STUDIES THAT WERE CARRIED OUT DURING THE 1960S AND 1970S. THE PRENATAL RESTRAINT STRESS MODEL OF SZ IS BASED ON A PROLONGED STRESS PARADIGM ADMINISTERED TO PREGNANT DAMS DURING GESTATION DAYS 7-21. THE ADULT OFFSPRING OF THESE DAMS SHOW VARIOUS BEHAVIORAL AND BIOCHEMICAL DEFICITS IN ADULTHOOD. BOTH MODELS ARE EPIGENETIC IN ORIGIN AND MIMIC THE POSITIVE AND NEGATIVE SYMPTOMS, AS WELL AS THE COGNITIVE ENDOPHENOTYPES COMMONLY OBSERVED IN SZ PATIENTS. WE ALSO DISCUSS THE UTILITY OF TYPICAL AND ATYPICAL ANTIPSYCHOTIC DRUGS IN ALLEVIATING THESE SYMPTOMS IN EACH MODEL. 2018 13 252 27 ADVANCEMENTS IN THE UNDERLYING PATHOGENESIS OF SCHIZOPHRENIA: IMPLICATIONS OF DNA METHYLATION IN GLIAL CELLS. SCHIZOPHRENIA (SZ) IS A CHRONIC AND SEVERE MENTAL ILLNESS FOR WHICH CURRENTLY THERE IS NO CURE. AT PRESENT, THE EXACT MOLECULAR MECHANISM INVOLVED IN THE UNDERLYING PATHOGENESIS OF SZ IS UNKNOWN. THE DISEASE IS THOUGHT TO BE CAUSED BY A COMBINATION OF GENETIC, BIOLOGICAL, PSYCHOLOGICAL, AND ENVIRONMENTAL FACTORS. RECENT STUDIES HAVE SHOWN THAT EPIGENETIC REGULATION IS INVOLVED IN SZ PATHOLOGY. SPECIFICALLY, DNA METHYLATION, ONE OF THE EARLIEST FOUND EPIGENETIC MODIFICATIONS, HAS BEEN EXTENSIVELY LINKED TO MODULATION OF NEURONAL FUNCTION, LEADING TO PSYCHIATRIC DISORDERS SUCH AS SZ. HOWEVER, INCREASING EVIDENCE INDICATES THAT GLIAL CELLS, ESPECIALLY DYSFUNCTIONAL OLIGODENDROCYTES UNDERGO DNA METHYLATION CHANGES THAT CONTRIBUTE TO THE PATHOGENESIS OF SZ. THIS REVIEW PRIMARILY FOCUSES ON DNA METHYLATION INVOLVED IN GLIAL DYSFUNCTIONS IN SZ. CLARIFYING THIS MECHANISM MAY LEAD TO THE DEVELOPMENT OF NEW THERAPEUTIC INTERVENTIONAL STRATEGIES FOR THE TREATMENT OF SZ AND OTHER ILLNESSES BY CORRECTING ABNORMAL METHYLATION IN GLIAL CELLS. 2015 14 6897 17 [TELOMERE-TELOMERASE SYSTEM IN AGING, NORM AND PATHOLOGY (LITERATURE REVIEW)]. THIS LITERATURE REVIEW PRESENTS RESULTS OF RESEARCH SHOWING ASSOCIATION BETWEEN FUNCTIONAL ACTIVITY OF THE TELOMERE-TELOMERASE SYSTEM AND MENTAL COGNITIVE AND EMOTIONAL PROCESSES IN NORMAL AND VARIOUS PATHOLOGICAL STATES: CHRONIC STRESS, DEPRESSION, BIPOLAR DISORDER, SCHIZOPHRENIA, MILD COGNITIVE IMPAIRMENT AND DEMENTIA IN AGING. IT ALSO REFERS TO AGE-SPECIFIC, PSYCHO-SOCIAL, ECONOMIC, IMMUNOLOGICAL, GENETIC AND EPIGENETIC FACTORS THAT INFLUENCE THESE RELATIONSHIPS. 2017 15 89 28 A PILOT INVESTIGATION OF DIFFERENTIAL HYDROXYMETHYLATION LEVELS IN PATIENT-DERIVED NEURAL STEM CELLS IMPLICATES ALTERED CORTICAL DEVELOPMENT IN BIPOLAR DISORDER. INTRODUCTION: BIPOLAR DISORDER (BD) IS A CHRONIC MENTAL ILLNESS CHARACTERIZED BY RECURRENT EPISODES OF MANIA AND DEPRESSION AND ASSOCIATED WITH SOCIAL AND COGNITIVE DISTURBANCES. ENVIRONMENTAL FACTORS, SUCH AS MATERNAL SMOKING AND CHILDHOOD TRAUMA, ARE BELIEVED TO MODULATE RISK GENOTYPES AND CONTRIBUTE TO THE PATHOGENESIS OF BD, SUGGESTING A KEY ROLE IN EPIGENETIC REGULATION DURING NEURODEVELOPMENT. 5-HYDROXYMETHYLCYTOSINE (5HMC) IS AN EPIGENETIC VARIANT OF PARTICULAR INTEREST, AS IT IS HIGHLY EXPRESSED IN THE BRAIN AND IS IMPLICATED IN NEURODEVELOPMENT, AND PSYCHIATRIC AND NEUROLOGICAL DISORDERS. METHODS: INDUCED PLURIPOTENT STEM CELLS (IPSCS) WERE GENERATED FROM THE WHITE BLOOD CELLS OF TWO ADOLESCENT PATIENTS WITH BIPOLAR DISORDER AND THEIR SAME-SEX AGE-MATCHED UNAFFECTED SIBLINGS (N = 4). FURTHER, IPSCS WERE DIFFERENTIATED INTO NEURONAL STEM CELLS (NSCS) AND CHARACTERIZED FOR PURITY USING IMMUNO-FLUORESCENCE. WE USED REDUCED REPRESENTATION HYDROXYMETHYLATION PROFILING (RRHP) TO PERFORM GENOME-WIDE 5HMC PROFILING OF IPSCS AND NSCS, TO MODEL 5HMC CHANGES DURING NEURONAL DIFFERENTIATION AND ASSESS THEIR IMPACT ON BD RISK. FUNCTIONAL ANNOTATION AND ENRICHMENT TESTING OF GENES HARBORING DIFFERENTIATED 5HMC LOCI WERE PERFORMED WITH THE ONLINE TOOL DAVID. RESULTS: APPROXIMATELY 2 MILLION SITES WERE MAPPED AND QUANTIFIED, WITH THE MAJORITY (68.8%) LOCATED IN GENIC REGIONS, WITH ELEVATED 5HMC LEVELS PER SITE OBSERVED FOR 3' UTRS, EXONS, AND 2-KB SHORELINES OF CPG ISLANDS. PAIRED T-TESTS OF NORMALIZED 5HMC COUNTS BETWEEN IPSC AND NSC CELL LINES REVEALED GLOBAL HYPO-HYDROXYMETHYLATION IN NSCS AND ENRICHMENT OF DIFFERENTIALLY HYDROXYMETHYLATED SITES WITHIN GENES ASSOCIATED WITH PLASMA MEMBRANE (FDR = 9.1 X 10(-12)) AND AXON GUIDANCE (FDR = 2.1 X 10(-6)), AMONG OTHER NEURONAL PROCESSES. THE MOST SIGNIFICANT DIFFERENCE WAS OBSERVED FOR A TRANSCRIPTION FACTOR BINDING SITE FOR THE KCNK9 GENE (P = 8.8 X 10(-6)), ENCODING A POTASSIUM CHANNEL PROTEIN INVOLVED IN NEURONAL ACTIVITY AND MIGRATION. PROTEIN-PROTEIN-INTERACTION (PPI) NETWORKING SHOWED SIGNIFICANT CONNECTIVITY (P = 3.2 X 10(-10)) BETWEEN PROTEINS ENCODED BY GENES HARBORING HIGHLY DIFFERENTIATED 5HMC SITES, WITH GENES INVOLVED IN AXON GUIDANCE AND ION TRANSMEMBRANE TRANSPORT FORMING DISTINCT SUB-CLUSTERS. COMPARISON OF NSCS OF BD CASES AND UNAFFECTED SIBLINGS REVEALED ADDITIONAL PATTERNS OF DIFFERENTIATION IN HYDROXYMETHYLATION LEVELS, INCLUDING SITES IN GENES WITH FUNCTIONS RELATED TO SYNAPSE FORMATION AND REGULATION, SUCH AS CUX2 (P = 2.4 X 10(-5)) AND DOK-7 (P = 3.6 X 10(-3)), AS WELL AS AN ENRICHMENT OF GENES INVOLVED IN THE EXTRACELLULAR MATRIX (FDR = 1.0 X 10(-8)). DISCUSSION: TOGETHER, THESE PRELIMINARY RESULTS LEND EVIDENCE TOWARD A POTENTIAL ROLE FOR 5HMC IN BOTH EARLY NEURONAL DIFFERENTIATION AND BD RISK, WITH VALIDATION AND MORE COMPREHENSIVE CHARACTERIZATION TO BE ACHIEVED THROUGH FOLLOW-UP STUDY. 2023 16 5267 21 PROMOTER ACTIVITY-BASED CASE-CONTROL ASSOCIATION STUDY ON SLC6A4 HIGHLIGHTING HYPERMETHYLATION AND ALTERED AMYGDALA VOLUME IN MALE PATIENTS WITH SCHIZOPHRENIA. ASSOCIATIONS BETWEEN ALTERED DNA METHYLATION OF THE SEROTONIN TRANSPORTER (5-HTT)-ENCODING GENE SLC6A4 AND EARLY LIFE ADVERSITY, MOOD AND ANXIETY DISORDERS, AND AMYGDALA REACTIVITY HAVE BEEN REPORTED. HOWEVER, FEW STUDIES HAVE EXAMINED EPIGENETIC ALTERATIONS OF SLC6A4 IN SCHIZOPHRENIA (SZ). WE EXAMINED CPG SITES OF SLC6A4, WHOSE DNA METHYLATION LEVELS HAVE BEEN REPORTED TO BE ALTERED IN BIPOLAR DISORDER, USING 3 INDEPENDENT COHORTS OF PATIENTS WITH SZ AND AGE-MATCHED CONTROLS. WE FOUND SIGNIFICANT HYPERMETHYLATION OF A CPG SITE IN SLC6A4 IN MALE PATIENTS WITH SZ IN ALL 3 COHORTS. WE SHOWED THAT CHRONIC ADMINISTRATION OF RISPERIDONE DID NOT AFFECT THE DNA METHYLATION STATUS AT THIS CPG SITE USING COMMON MARMOSETS, AND THAT IN VITRO DNA METHYLATION AT THIS CPG SITE DIMINISHED THE PROMOTER ACTIVITY OF SLC6A4. WE THEN GENOTYPED THE 5-HTT-LINKED POLYMORPHIC REGION (5-HTTLPR) AND INVESTIGATED THE RELATIONSHIP AMONG 5-HTTLPR, DNA METHYLATION, AND AMYGDALA VOLUME USING BRAIN IMAGING DATA. WE FOUND THAT PATIENTS HARBORING LOW-ACTIVITY 5-HTTLPR ALLELES SHOWED HYPERMETHYLATION AND THEY SHOWED A NEGATIVE CORRELATION BETWEEN DNA METHYLATION LEVELS AND LEFT AMYGDALA VOLUMES. THESE RESULTS SUGGEST THAT HYPERMETHYLATION OF THE CPG SITE IN SLC6A4 IS INVOLVED IN THE PATHOPHYSIOLOGY OF SZ, ESPECIALLY IN MALE PATIENTS HARBORING LOW-ACTIVITY 5-HTTLPR ALLELES. 2020 17 4313 24 MICRORNAS AS CANDIDATES FOR BIPOLAR DISORDER BIOMARKERS. BIPOLAR DISORDER (BD) IS A COMMON, RECURRING PSYCHIATRIC ILLNESS WITH UNKNOWN PATHOGENESIS. MUCH LIKE OTHER PSYCHIATRIC DISEASES, BD SUFFERS FROM THE CHRONIC LACK OF RELIABLE BIOMARKERS AND INNOVATIVE PHARMACOLOGICAL INTERVENTIONS. BETTER CHARACTERIZATION OF CLINICAL PROFILES, EXPERIMENTAL MEDICINE, GENOMIC DATA MINING, AND THE UTILIZATION OF EXPERIMENTAL MODELS, INCLUDING STEM CELL AND GENETICALLY MODIFIED MICE, ARE SUGGESTED WAYS FORWARD. ENVIRONMENT, INCLUDING EARLY CHILDHOOD EXPERIENCES, HAS BEEN DOCUMENTED TO MODULATE THE RISK FOR THE DEVELOPMENT OF PSYCHIATRIC DISORDERS VIA EPIGENETIC MECHANISMS. KEY EPIGENETIC REGULATORS, MICRORNAS (MIRNAS, MIRS), GOVERN NORMAL NEURONAL FUNCTIONING AND SHOW ALTERED EXPRESSION IN DIVERSE BRAIN PATHOLOGIES. WE OBSERVED SIGNIFICANT ALTERATIONS OF EXOSOMAL MIR-29C LEVELS IN PREFRONTAL CORTEX (BRODMANN AREA 9, BA9) OF BD PATIENTS. WE ALSO DEMONSTRATED THAT EXOSOMES EXTRACTED FROM THE ANTERIOR CINGULATE CORTEX (BA24), A CRUCIAL AREA FOR MODULATING EMOTIONAL EXPRESSION AND AFFECT, HAVE INCREASED LEVELS OF MIR-149 IN BD PATIENTS COMPARED TO CONTROLS. BECAUSE MIR-149 HAS BEEN SHOWN TO INHIBIT GLIAL PROLIFERATION, WE HYPOTHESIZED THAT INCREASED MIR-149 EXPRESSION IN BA24-DERIVED EXOSOMES MAY BE CONSISTENT WITH THE PREVIOUSLY REPORTED REDUCED GLIAL CELL NUMBERS IN BA24 OF PATIENTS DIAGNOSED WITH FAMILIAL BD. QPCR ANALYSIS OF LASER-MICRODISSECTED NEURONAL AND GLIAL CELLS FROM BA24 CORTICAL SAMPLES OF BD PATIENTS VERIFIED THAT THE GLIAL, BUT NOT NEURONAL, POPULATION EXHIBITS SIGNIFICANTLY INCREASED MIR-149 EXPRESSION. THESE FINDINGS SUPPORT NEURON-GLIA INTERACTION AS A POSSIBLE TARGET MECHANISM IN BD, IMPLICATED BY OTHERS IN NEUROIMAGING, POSTMORTEM, AND IN VIVO STUDIES OF THE PATHOLOGICAL CHANGES MEDIATED BY GLIAL CELLS. 2021 18 6062 25 THE DEVELOPMENTAL BASIS OF EPIGENETIC REGULATION OF HTR2A AND PSYCHIATRIC OUTCOMES. THE SEROTONIN RECEPTOR 5-HT2A (ENCODED BY HTR2A) IS AN IMPORTANT REGULATOR OF FETAL BRAIN DEVELOPMENT AND ADULT COGNITIVE FUNCTION. ENVIRONMENTAL SIGNALS THAT INDUCE EPIGENETIC CHANGES OF SEROTONIN RESPONSE GENES, INCLUDING HTR2A, HAVE BEEN IMPLICATED IN ADVERSE MENTAL HEALTH OUTCOMES. THE OBJECTIVE OF THIS PERSPECTIVE ARTICLE IS TO ADDRESS THE MEDICAL IMPLICATIONS OF HTR2A EPIGENETIC REGULATION, WHICH HAS BEEN ASSOCIATED WITH BOTH INFANT NEUROBEHAVIORAL OUTCOMES AND ADULT MENTAL HEALTH. ONGOING RESEARCH HAS IDENTIFIED A REGION OF THE HTR2A PROMOTER THAT HAS BEEN ASSOCIATED WITH A NUMBER OF MEDICAL OUTCOMES IN ADULTS AND INFANTS, INCLUDING BIPOLAR DISORDER, SCHIZOPHRENIA, CHRONIC FATIGUE SYNDROME, BORDERLINE PERSONALITY DISORDER, SUICIDALITY, AND NEUROBEHAVIORAL OUTCOMES. EPIGENETIC REGULATION OF HTR2A HAS BEEN STUDIED IN SEVERAL DIFFERENT TYPES OF TISSUES, INCLUDING THE PLACENTA. THE PLACENTA IS AN IMPORTANT SOURCE OF SEROTONIN DURING FETAL NEURODEVELOPMENT, AND PLACENTAL EPIGENETIC VARIATION OF HTR2A HAS BEEN ASSOCIATED WITH INFANT NEUROBEHAVIORAL OUTCOMES, WHICH MAY REPRESENT THE BASIS OF ADULT MENTAL HEALTH DISORDERS. FURTHER ANALYSIS IS NEEDED TO IDENTIFY INTRINSIC AND EXTRINSIC FACTORS THAT MODULATE HTR2A METHYLATION, AND THE MECHANISM BY WHICH THIS EPIGENETIC VARIATION INFLUENCES FETAL GROWTH AND LEADS TO ALTERED BRAIN DEVELOPMENT, MANIFESTING IN PSYCHIATRIC DISORDERS. 2014 19 2534 35 EPIGENETICS IN BIPOLAR DISORDER: A CRITICAL REVIEW OF THE LITERATURE. INTRODUCTION: BIPOLAR DISORDER (BD) IS A CHRONIC, DISABLING DISEASE CHARACTERISED BY ALTERNATE MOOD EPISODES, SWITCHING THROUGH DEPRESSIVE AND MANIC/HYPOMANIC PHASES. MOOD STABILIZERS, IN PARTICULAR LITHIUM SALTS, CONSTITUTE THE CORNERSTONE OF THE TREATMENT IN THE ACUTE PHASE AS WELL AS FOR THE PREVENTION OF RECURRENCES. THE PATHOPHYSIOLOGY OF BD AND THE MECHANISMS OF ACTION OF MOOD STABILIZERS REMAIN LARGELY UNKNOWN BUT SEVERAL PIECES OF EVIDENCE POINT TO GENE X ENVIRONMENT INTERACTIONS. EPIGENETICS, DEFINED AS THE REGULATION OF GENE EXPRESSION WITHOUT GENETIC CHANGES, COULD BE THE MOLECULAR SUBSTRATE OF THESE INTERACTIONS. IN THIS LITERATURE REVIEW, WE SUMMARIZE THE MAIN EPIGENETIC FINDINGS ASSOCIATED WITH BD AND RESPONSE TO MOOD STABILIZERS. METHODS: WE SEARCHED PUBMED, AND EMBASE DATABASES AND CLASSIFIED THE ARTICLES DEPENDING ON THE EPIGENETIC MECHANISMS (DNA METHYLATION, HISTONE MODIFICATIONS AND NON-CODING RNAS). RESULTS: WE PRESENT THE DIFFERENT EPIGENETIC MODIFICATIONS ASSOCIATED WITH BD OR WITH MOOD-STABILIZERS. THE MAJOR REPORTED MECHANISMS WERE DNA METHYLATION, HISTONE METHYLATION AND ACETYLATION, AND NON-CODING RNAS. OVERALL, THE ASSESSMENTS ARE POORLY HARMONIZED AND THE RESULTS ARE MORE LIMITED THAN IN OTHER PSYCHIATRIC DISORDERS (E.G. SCHIZOPHRENIA). HOWEVER, THE NATURE OF BD AND ITS TREATMENT OFFER EXCELLENT OPPORTUNITIES FOR EPIGENETIC RESEARCH: CLEAR IMPACT OF ENVIRONMENTAL FACTORS, CLINICAL VARIATION BETWEEN MANIC OR DEPRESSIVE EPISODES RESULTING IN POSSIBLE IDENTIFICATION OF STATE AND TRAITS BIOMARKERS, DOCUMENTED IMPACT OF MOOD-STABILIZERS ON THE EPIGENOME. CONCLUSION: EPIGENETIC IS A GROWING AND PROMISING FIELD IN BD THAT MAY SHED LIGHT ON ITS PATHOPHYSIOLOGY OR BE USEFUL AS BIOMARKERS OF RESPONSE TO MOOD-STABILIZER. 2021 20 4401 28 MODULATION OF NEURONAL PLASTICITY FOLLOWING CHRONIC CONCOMITANT ADMINISTRATION OF THE NOVEL ANTIPSYCHOTIC LURASIDONE WITH THE MOOD STABILIZER VALPROIC ACID. RATIONALE: COMBINATORY THERAPY IS WIDELY USED IN PSYCHIATRY OWING TO THE POSSIBILITY THAT DRUGS WITH DIFFERENT MECHANISMS OF ACTION MAY SYNERGIZE TO IMPROVE FUNCTIONS DETERIORATED IN SCHIZOPHRENIA, BIPOLAR DISORDERS, AND MAJOR DEPRESSION. WHILE COMBINATORY STRATEGIES RELY ON RECEPTOR AND SYNAPTIC MECHANISMS, IT SHOULD ALSO BE CONSIDERED THAT TWO DRUGS MAY ALSO "INTERACT" ON THE LONG-TERM TO DETERMINE MORE ROBUST CHANGES IN NEURONAL PLASTICITY, WHICH REPRESENTS A DOWNSTREAM TARGET IMPORTANT FOR FUNCTIONAL RECOVERY. OBJECTIVE: THE AIM OF THE STUDY IS TO INVESTIGATE NEUROADAPTIVE CHANGES SET IN MOTION BY CHRONIC CONCOMITANT ADMINISTRATION OF THE NOVEL ANTIPSYCHOTIC LURASIDONE AND THE MOOD STABILIZER VALPROATE. METHODS: ANIMALS WERE CHRONICALLY TREATED WITH LURASIDONE, VALPROATE, OR THE COMBINATION OF THE TWO DRUGS AND KILLED 24 H AFTER THE LAST INJECTION TO EVALUATE ALTERATIONS OF DIFFERENT MEASURES OF NEURONAL PLASTICITY SUCH AS THE NEUROTROPHIN BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF), THE IMMEDIATE EARLY GENE ACTIVITY-REGULATED CYTOSKELETAL ASSOCIATED PROTEIN, AND THE EPIGENETIC REGULATORS HDAC 1, 2, AND 5 IN DORSAL AND VENTRAL HIPPOCAMPUS. RESULTS: THE RESULTS SUGGEST THAT COADMINISTRATION OF LURASIDONE AND VALPROATE PRODUCES, WHEN COMPARED TO THE SINGLE DRUGS, A LARGER INCREASE IN THE EXPRESSION OF BDNF IN THE VENTRAL HIPPOCAMPUS, THROUGH THE REGULATION OF SPECIFIC NEUROTROPHIN TRANSCRIPTS. WE ALSO FOUND THAT THE HISTONE DEACETYLASES WERE REGULATED BY THE DRUG COMBINATION, SUGGESTING THAT SOME OF THE TRANSCRIPTIONAL CHANGES MAY BE SUSTAINED BY EPIGENETIC MECHANISMS. CONCLUSIONS: OUR RESULTS SUGGEST THAT THE BENEFICIAL EFFECTS ASSOCIATED WITH COMBINATORY TREATMENT BETWEEN A SECOND-GENERATION ANTIPSYCHOTIC AND A MOOD STABILIZER COULD RESULT FROM THE ABILITY TO MODULATE NEUROPLASTIC MOLECULES, WHOSE EXPRESSION AND FUNCTION IS DETERIORATED IN DIFFERENT PSYCHIATRIC CONDITIONS. 2013