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Depression and suicidality are prevalent in youth and are associated with a range of negative outcomes. The current study aimed to evaluate a measurement-based care (MBC) software (VitalSign6) tool to improve the screening and treatment of depression and suicidality in youth aged 8-17 years within a rural, underserved population. To assess for depression and suicidality, the Patient Health Questionnaire-2 was administered as an initial screen, and the Patient Health Questionnaire-9 Modified for Adolescents (PHQ-9-A) was administered if the initial screen was positive. Data were collected at medical clinics over one year, and descriptive statistics and t-tests or Wilcoxon-Mann-Whitney tests were conducted. A total of 1,984 youth were initially screened (mean age of 13 years; 51.6% female); 24.2% screened positive for depression, and 14.9% endorsed suicidality. Of those who screened positive, the mean PHQ-9-A score was 12.8; 66.9% had PHQ-9-A scores in the moderate to severe range, and 44.2% endorsed suicidality. Almost half of the youth who screened positive for depression had at least one follow-up assessment, and about one quarter achieved remission 4 months after initial screening. Adolescents (12-17 years) had higher PHQ-9-A scores, higher suicidality, and more follow-up assessments than younger youth (8-11 years). Younger youth had higher rates of remission. The widespread use of MBC was feasible in this setting. It is important to utilize MBC to identify and treat youth with depression and suicidality and to do so in younger populations to improve their trajectory over time; VitalSign6 is one tool to help achieve these goals.
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There is a high prevalence of untreated depression in adults and youth observed at the population level in the United States, and many who would benefit from treatment do not receive it. One proposed effort to increase access to care is the use of measurement-based care (MBC; repeated use of symptom measures for screening and treatment guidance) by primary care physicians to treat non-complex cases of depression. MBC has been shown to improve patient outcomes compared to care as usual, but there are barriers that need to be addressed at the health system level for effective implementation to occur. Herein we provide an overview of MBC and detail benefits and barriers of MBC implementation. Relevant considerations and guidance for implementing MBC are presented, and a case example of a health system implementing MBC is included. Though issues of reimbursement, limited human and technological resources, and resistance to systemic change are barriers to implementing MBC, effective strategies exist to overcome these barriers. In addition to helping health systems align with changes to value-based care models, effective implementation of MBC can likely improve patient outcomes and result in net financial benefits.
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Integration of measurement-based care (MBC) into clinical practice has shown promise in improving treatment outcomes for depression. Yet, without a gold standard measure of MBC, assessing fidelity to the MBC model across various clinical settings is difficult. A central goal of the Texas Youth Depression and Suicide Research Network (TX-YDSRN) was to characterize MBC across the state of Texas through the development of a standardized tool to assess the use of MBC strategies when assessing depression, anxiety, side effects, and treatment adherence. A chart review of clinical visits indicated standardized depression measures (71.2%) and anxiety measures (64%) were being utilized across sites. The use of standardized measures to assess medication adherence and side effects was limited to less than six percent for both, with the majority utilizing clinical interviews to assess adherence and side effects; yet medication was changed in nearly half. Rates of utilization of standardized measures for participants with multiple MBC forms were similar to those who only provided one form.
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3,4-Methylenedioxy-N-methylcathinone (methylone) is a new psychoactive substance with stimulant properties and potential for abuse. Despite its popularity, limited studies have examined relationships between brain concentrations of methylone, its metabolites, and pharmacodynamic effects. The goal of the present study was 2-fold: 1) to determine pharmacokinetics of methylone and its major metabolites-4-hydroxy-3-methoxy-N-methylcathinone (HMMC), 3,4-dihydroxy-N-methylcathinone (HHMC), and 3,4-methylenedioxycathinone (MDC)-in rat brain and plasma and 2) to relate brain pharmacokinetic parameters to pharmacodynamic effects including locomotor behavior and postmortem neurochemistry. Male Sprague-Dawley rats received subcutaneous methylone (6, 12, or 24 mg/kg) or saline vehicle (n = 16/dose), and subgroups were decapitated after 40 or 120 minutes. Plasma and prefrontal cortex were analyzed for concentrations of methylone and its metabolites by liquid chromatography-tandem mass spectrometry. Frontal cortex and dorsal striatum were analyzed for dopamine, 5-HT, and their metabolites by high-performance liquid chromatography-electrochemical detection. Brain and plasma concentrations of methylone and its metabolites rose with increasing methylone dose, but brain methylone and MDC concentrations were greater than dose-proportional. Brain-to-plasma ratios for methylone and MDC were ≥ 3 (range 3-12), whereas those for HHMC and HMMC were ≤ 0.2 (range 0.01-0.2). Locomotor activity score was positively correlated with brain methylone and MDC, whereas cortical 5-HT was negatively correlated with these analytes at 120 minutes. Our findings show that brain concentrations of methylone and MDC display nonlinear accumulation. Behavioral and neurochemical effects of systemically administered methylone are related to brain concentrations of methylone and MDC but not its hydroxylated metabolites, which do not effectively penetrate into the brain. SIGNIFICANCE STATEMENT: Behavioral and neurochemical effects of methylone are related to brain concentrations of methylone and its metabolite MDC but not its hydroxylated metabolites, 4-hydroxy-3-methoxy-N-methylcathinone and 3,4-dihydroxy-N-methylcathinone, which do not effectively penetrate into the brain. Methylone and MDC display nonlinear accumulation in the brain, which could cause untoward effects on serotonin neurons in vulnerable brain regions, including the frontal cortex.
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Encéfalo , Animais , Dopamina , Ratos , SerotoninaRESUMO
Clinical descriptions of cocaine addiction include compulsive drug seeking and maladaptive decision-making despite substantial aversive consequences. Research suggests that this may result from altered orbitofrontal cortex (OFC) function and its participation in outcome-based behavior. Clinical and animal studies also implicate serotonin in the regulation of OFC function in addiction and other neuropsychiatric disorders. Here we test the hypothesis that exposure to cocaine, through self-administration (CSA) or yoked-administration (CYA), alters the regulation of OFC function by 5-HT. Using whole-cell electrophysiology in brain slices from naïve rats we find that 5-HT1A receptors generate hyperpolarizing outward currents in layer-V OFC pyramidal neurons, and that 5-HT2A receptors increase glutamate release onto these cells. Following extended withdrawal from CSA or CYA, this 5-HT regulation of OFC activity is largely lost. In-situ hybridization of 5-HT receptor transcripts reveals that 5-HT1A receptor mRNA is unaffected and 5-HT2A receptor mRNA is significantly elevated after CSA or CYA. These results demonstrate that 5-HT control of OFC neurons is disrupted for extended periods following cocaine exposure. We hypothesize that this dysregulation of 5-HT signaling leads to enduring disruptions of OFC network activity that this is involved in impaired decision-making associated with cocaine addiction.
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Transtornos Relacionados ao Uso de Cocaína/metabolismo , Cocaína/administração & dosagem , Inibidores da Captação de Dopamina/administração & dosagem , Córtex Pré-Frontal/efeitos dos fármacos , Serotonina/metabolismo , Animais , Transtornos Relacionados ao Uso de Cocaína/patologia , Ácido Glutâmico/metabolismo , Hibridização In Situ , Masculino , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Técnicas de Patch-Clamp , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/patologia , RNA Mensageiro/metabolismo , Ratos Long-Evans , Receptor 5-HT1A de Serotonina/metabolismo , Receptor 5-HT2A de Serotonina/metabolismo , Autoadministração , Técnicas de Cultura de TecidosRESUMO
Cannabis use is increasingly common. There is a need for validated tools to meaningfully assess recreational, medical, and disordered cannabis use in both research and clinical contexts. Cannabis assessments were considered against pre-determined inclusion criteria within a comprehensive review. Measures were categorized as either (i) evaluating use frequency or quantity, (ii) measuring symptoms of disordered use and withdrawal, or (iii) assessing use motives, effects, and perceptions. The applications and validations for each assessment are summarized. Finally, recommendations for refining of existing measures or development of new measures are presented. The literature review resulted in 289 publications that were reviewed in detail, yielding 21 assessments that met inclusion criteria. The applications of these assessments are described here, in addition to the information about the validation studies of each assessment. Based on the complication of these tools, 5 areas of potential development are highlighted to guide future research, including (i) sensitivity to the mode of cannabis administration as well as sensitivity to (ii) potency of cannabis products alongside frequency and quantity, (iii) unit equivalence, (iv) aligning clinical measures consistently with cannabis use disorder (CUD) diagnostic criteria, and (v) creating measures specific to medical users, their motives for use, and their perceptions of therapeutic benefits or side effects. Clinicians and researchers can pragmatically benefit from this summary of validated measures of cannabis use, and future work could improve the study of and clinical care for cannabis use and CUD by pursuing one or more key areas of development described here.
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Background: Similar outcomes and remission rates have been found for the treatment of depression in adults in primary and psychiatric care settings. However, comparatively little is known about how pediatric depression is managed across different settings. This study aims to address this gap by comparing depression treatment in pediatric and psychiatric settings. We hypothesized that pediatric care settings would be more likely to treat individuals with lower depression severity and would select pharmacotherapy less frequently as a treatment option. Methods: Patients (n = 3498) were screened for depression at a children's hospital from May 2017 to May 2022 as part of the VitalSign6 project, a web-based application for depression management. The two-item patient health questionnaire (PHQ) was used for screening, and the data set contains patient-reported measures and provider-reported diagnoses and treatment selections at each clinic visit. Patients with nine-item PHQ (PHQ-9) scores ≥10 at baseline were included in the analysis to compare diagnosis and treatment recommendations between pediatric and psychiatric settings. Results: Among the 1323 patients who screened positive for depression, those in psychiatric settings had higher PHQ-9 scores (15.9 ± 5.0 vs. 12.1 ± 5.5; p < 0.0001). Patients with PHQ-9 ≥ 10 in psychiatric settings were more likely to be diagnosed with major depressive disorder (60.6% vs. 24.7%, p < 0.0001) and receive pharmacotherapy (54.8% vs. 6.6%) than those in pediatric settings. Pediatric setting patients were more likely to receive nonpharmacological treatment alone (36.3% vs. 4.3%) or an outside referral (27.7% vs. 5.7%). Remission rates did not significantly differ between the two settings. Conclusions: Youth in psychiatric settings are more likely to screen positive for depression and to have greater depression severity than those in pediatric settings. Both settings provide treatment recommendations for moderate-to-severe depression, but treatment types vary substantially. Yet, remission rates remain similar. Further research is needed to understand the nuances of treatment differences and their implications.
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Transtorno Depressivo Maior , Adulto , Humanos , Adolescente , Criança , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/tratamento farmacológico , Depressão/diagnóstico , Depressão/tratamento farmacológico , Psicoterapia , Assistência Ambulatorial , Centros Médicos AcadêmicosRESUMO
Rates of depression in youth are continuing to increase at a steady rate, yet these youth often do not receive mental health services (Bertha & Balázs, 2013; Thomas et al., 2011). Schools are an ideal setting to connect youth to mental health services; however, many barriers exist with respect to schools having adequate resources and access to the appropriate levels of services (Duong et al., 2021; Owens & Peltier, 2002). Schools may collaborate with local community providers with available resources to address these gaps. The current article describes the pilot of a school-based mental health promotion program intended to reduce depression in youth by promoting access to care through referrals to community providers. Data were collected, via self-report measures, every 3 months for 12 months from students from three middle and high schools in North Texas. The students (N = 88) enrolled in this program experienced significant reductions in their depression symptoms at the end of 12 months. This program highlights the importance of school-community partnerships to promote access to care to address mental health concerns. The results from our pilot study demonstrate the feasibility and the potential of school-based programs in improving the mental health of youth in schools through community partnership. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
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Depressão , Pobreza , Serviços de Saúde Mental Escolar , Estudantes , Humanos , Projetos Piloto , Adolescente , Masculino , Feminino , Depressão/terapia , Estudantes/psicologia , Instituições Acadêmicas , Texas , Acessibilidade aos Serviços de Saúde , Serviços de Saúde Escolar , Promoção da Saúde/métodosRESUMO
OBJECTIVE: The burden of major depressive disorder is compounded by a limited understanding of its risk factors, the limited efficacy of treatments, and the lack of precision approaches to guide treatment selection. The Texas Resilience Against Depression (T-RAD) study was designed to explore the etiology of depression by collecting comprehensive socio-demographic, clinical, behavioral, neurophysiological/neuroimaging, and biological data from depressed individuals (D2K) and youth at risk for depression (RAD). METHODS: This report details the baseline sociodemographic, clinical, and functional features from the initial cohort (D2K Nâ¯=â¯1040, RAD Nâ¯=â¯365). RESULTS: Of the total T-RAD sample, nâ¯=â¯1078 (76.73â¯%) attended ≥2 in-person visits, and nâ¯=â¯845 (60.14â¯%) attended ≥4 in-person visits. Most D2K (84.82â¯%) had a primary diagnosis of any depressive disorder, with a bipolar disorder diagnosis being prevalent (13.49â¯%). RAD participants (75.89â¯%) did not have a psychiatric diagnosis, but other non-depressive diagnoses were present. D2K participants had 9-item Patient Health Questionnaire scores at or near the moderate range (10.58⯱â¯6.42â¯>â¯24â¯yrs.; 9.73⯱â¯6.12 10-24â¯yrs). RAD participants were in the non-depressed range (2.19⯱â¯2.65). While the age ranges in D2K and RAD differ, the potential to conduct analyses that compare at-risk and depressed youth is a strength of the study. The opportunity to examine the trajectory of depressive symptoms in the D2K cohort over the lifespan is unique. LIMITATIONS: As a longitudinal study, missing data were common. CONCLUSION: T-RAD will allow data to be collected from multiple modalities on a clinically well-characterized sample. These data will drive important discoveries on diagnosis, treatment, and prevention of depression.
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Rates of youth depression and suicide are rising worldwide and represent public health crises. The present study examined the relationship between trauma history and symptoms of depression, suicidal ideation, and anxiety among suicidal and depressed youth. A diverse group of 1000 8-20-year-olds enrolled in the statewide Texas Youth Depression and Suicide Research Network (TX-YDSRN) reported their trauma history (Traumatic Events Screening Inventory for Children) and symptoms of depression (Patient Health Questionnaire for adolescents; PHQ-A), anxiety (Generalized Anxiety Disorder scale; GAD-7), and suicidality (Concise Health Risk Tracking scale; CHRT-SR). Nearly half of the sample reported exposure to multiple categories of traumatic experiences. Number of trauma exposure categories significantly predicted PHQ-A and GAD-7 scores. Exposure to interpersonal trauma and to sexual trauma were significantly associated with PHQ-A, GAD-7, and CHRT-SR scores. The number of trauma exposure categories was associated with increased levels of anxiety and depression; however, only exposure to interpersonal or sexual trauma was associated with more suicidality. Clinicians should assess trauma exposure in patients seeking psychiatric care, especially for interpersonal and sexual trauma, which may be predictive of increased risk for suicidality in depressed youth. Future work should disentangle the effects of specific trauma types from multiple trauma exposure.
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Depressão , Suicídio , Criança , Humanos , Adolescente , Depressão/epidemiologia , Depressão/psicologia , Saúde Mental , Texas/epidemiologia , Psicometria , Suicídio/psicologia , Ideação SuicidaRESUMO
BACKGROUND: Major depressive disorder (MDD) is common in youth and among the most frequent comorbid disorders in pediatric obsessive-compulsive disorder (OCD), but it is unclear whether the presence of OCD affects the symptom presentation of MDD in youth. METHODS: A sample of youth with OCD and MDD (n = 124) and a sample of youth with MDD but no OCD (n = 673) completed the Patient Health Questionnaire for Adolescents (PHQ-A). The overall and symptom-level presentation of MDD were examined using group comparisons and network analysis. RESULTS: Youth with MDD and OCD, compared to those with MDD and no OCD, had more severe MDD (Cohen's d = 0.39) and more reported moderate to severe depression (75 % vs 61 %). When accounting for demographic variables and the overall severity of MDD, those with comorbid OCD reported lower levels of anhedonia and more severe difficulties with psychomotor retardation/agitation. No significant differences in the interconnections among symptoms emerged. LIMITATIONS: Data were cross-sectional and self-reported, gold standard diagnostic tools were not used to assess OCD, and the sample size for the group with MDD and OCD was relatively small yielding low statistical power for network analysis. CONCLUSIONS: Youth with MDD and OCD have more severe MDD than those with MDD and no OCD and they experience more psychomotor issues and less anhedonia, which may relate to the behavioral activation characteristic of OCD.
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Transtorno Depressivo Maior , Transtorno Obsessivo-Compulsivo , Humanos , Adolescente , Criança , Transtorno Depressivo Maior/complicações , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/epidemiologia , Anedonia , Comorbidade , Transtorno Obsessivo-Compulsivo/diagnóstico , Transtorno Obsessivo-Compulsivo/epidemiologia , Transtornos de Ansiedade/epidemiologiaRESUMO
Highly potent cannabis concentrates are widely available and associated with affective disturbance and cannabis use disorder. Little is known about the effects of concentrated Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) and their relationship to long-term affect. We explored how baseline affective symptoms (anxiety and depression) relate to acute (i.e., immediate or short-term) subjective mood and intoxication effects during naturalistic use of cannabis concentrates. Fifty-four cannabis users (48% female; Mage = 29.87) were assigned to ad libitum use of either a THC-dominant (84.99% THC and THCa, < 1% CBD) or CBD-dominant (74.7% CBD, 4.1% CBDa, 4.5% THC and THCa) concentrate. Individuals were assessed at baseline and before, immediately after, and 1 hr after naturalistic use of their assigned product. Models regressed each outcome on time, product condition, baseline affective symptoms, and their interactions. An interaction emerged between condition and baseline depression symptoms on positive mood (F = 9.47, p < .005); higher depression symptom level was associated with higher positive mood with THC-dominant product use. There was an interaction between condition, baseline depression symptoms, and time on negative mood (F = 5.55, p < .01); negative mood decreased with CBD-dominant product use for all depression symptom levels but increased with THC-dominant product use at high levels. Finally, there was an interaction between condition and time on intoxication (F = 3.72, p = .03); the THC-dominant condition was more intoxicated postuse than the CBD-dominant condition. This novel exploratory study suggests that baseline affect moderates the acute effects of ad libitum use of THC and CBD concentrates such that preexisting affective symptoms modulate the intensity of subjective drug experiences. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
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Canabidiol , Cannabis , Alucinógenos , Humanos , Feminino , Adulto , Masculino , Canabidiol/farmacologia , Dronabinol/farmacologia , Alucinógenos/farmacologia , Ansiedade/tratamento farmacológico , Agonistas de Receptores de CanabinoidesRESUMO
BACKGROUND: MDPV (3,4-methylenedioxypyrovalerone) is a synthetic stimulant that blocks transmitter uptake at transporters for dopamine and norepinephrine. Less is known about MDPV pharmacokinetics, especially with respect to brain concentrations of the drug and its metabolites. OBJECTIVES: The goal of the present study was: 1) to determine brain concentrations of MDPV and its metabolites, 3,4-dihydroxypyrovalerone (3,4-catechol-PV) and 4-hydroxy-3-methoxy-pyrovalerone (4-OH-3-MeOPV), after administration of MDPV, and 2) to relate brain pharmacokinetic measures to pharmacodynamic endpoints in the same subjects. METHODS: Male Sprague-Dawley rats (300-400 g) received s.c. MDPV injection (1, 2, or 4 mg/kg) or its saline vehicle. Groups of rats were decapitated at 40 min and 240 min postinjection. Locomotor behavior was rated before decapitation, and the core temperature was obtained. Plasma and frontal cortex were analyzed to quantitate MDPV and its metabolites. Striatal samples were analyzed to measure dopamine, serotonin (5-HT), and their metabolites. RESULTS: MDPV displayed brain-to-plasma ratios greater than 1 (range 8.8-12.1), whereas 3,4-catechol-PV and 4-OH-3-MeO-PV showed ratios less than 1 (range 0-0.3). MDPV increased behavioural scores reflective of locomotor stimulation at 40 and 240 min and produced slight hyperthermia at 240 min. MDPV had no effect on striatal dopamine but produced an increase in the metabolite homovanillic acid (HVA). Brain MDPV concentrations were positively correlated with behavioural scores and striatal HVA but not with other endpoints. CONCLUSION: The behavioural effects of MDPV are related to brain concentrations of the parent drug and not its metabolites. The modest effects of MDPV on monoamine systems suggest that other non-monoamine mechanisms may contribute to the effects of the drug in vivo.
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Dopamina , Serotonina , Animais , Ratos , Masculino , Dopamina/metabolismo , Ratos Sprague-Dawley , Ácido Homovanílico/farmacologia , Pirrolidinas/farmacocinética , Encéfalo , Norepinefrina , Relação Dose-Resposta a DrogaRESUMO
OBJECTIVE: We report the transcranial functional photoacoustic (fPA) neuroimaging of N-methyl-D-aspartate (NMDA) evoked neural activity in the rat hippocampus. Concurrent quantitative electroencephalography (qEEG) and microdialysis were used to record real-time circuit dynamics and excitatory neurotransmitter concentrations, respectively. APPROACH: We hypothesized that location-specific fPA voltage-sensitive dye (VSD) contrast would identify neural activity changes in the hippocampus which correlate with NMDA-evoked excitatory neurotransmission. MAIN RESULTS: Transcranial fPA VSD imaging at the contralateral side of the microdialysis probe provided NMDA-evoked VSD responses with positive correlation to extracellular glutamate concentration changes. qEEG validated a wide range of glutamatergic excitation, which culminated in focal seizure activity after a high NMDA dose. We conclude that transcranial fPA VSD imaging can distinguish focal glutamate loads in the rat hippocampus, based on the VSD redistribution mechanism which is sensitive to the electrophysiologic membrane potential. SIGNIFICANCE: Our results suggest the future utility of this emerging technology in both laboratory and clinical sciences as an innovative functional neuroimaging modality.
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N-Metilaspartato , Técnicas Fotoacústicas , Animais , Ácido Glutâmico , Hipocampo/diagnóstico por imagem , Neuroimagem , Ratos , Receptores de N-Metil-D-AspartatoRESUMO
Naphthalen-1-yl-(1-pentylindol-3-yl)methanone (JWH-018) is a synthetic compound found in psychoactive "spice" products that activates cannabinoid receptors. Preclinical evidence suggests that exposure to synthetic cannabinoids increases 5-HT2A/2C receptor function in the brain, an effect which might contribute to psychotic symptoms. Here, we hypothesized that repeated exposures to JWH-018 would enhance behavioral responsiveness to the 5-HT2A/2C receptor agonist DOI. Male Sprague-Dawley rats fitted with subcutaneously (sc) temperature transponders received daily injections of JWH-018 (1.0 mg/kg, sc) or its vehicle for seven consecutive days. Body temperature and catalepsy scores were determined at 1, 2, and 4 h post-injection each day. At 1 and 7 days after the final repeated treatment, rats received a challenge injection of either DOI (0.1 mg/kg, sc) or the 5-HT1A receptor agonist 8-OH-DPAT (0.3 mg/kg, sc), then temperature and behavioral responses were assessed. Behaviors induced by DOI included wet dog shakes and back muscle contractions (i.e., skin jerks), while behaviors induced by 8-OH-DPAT included ambulation, forepaw treading, and flat body posture. On the first day of repeated treatment, JWH-018 produced robust hypothermia and catalepsy which lasted up to 4 h, and these effects were significantly blunted by day 7 of treatment. Repeated exposure to JWH-018 did not affect behaviors induced by DOI, but behavioral and hypothermic responses induced by 8-OH-DPAT were significantly augmented 1 day after cessation of JWH-018 treatment. Collectively, our findings show that repeated treatment with JWH-018 produces tolerance to its hypothermic and cataleptic effects, which is accompanied by transient enhancement of 5-HT1A receptor sensitivity in vivo.
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2,5-Dimethoxyphenethylamines (2C compounds) are 5-HT2A/2C receptor agonists that induce hallucinogenic effects. N-methoxybenzylation of 2C compounds markedly increases their affinity for 5-HT2A receptors, and two such analogs, 2-(4-chloro-2,5-dimethoxyphenyl)-N-[(2-methoxyphenyl)methyl]ethanamine (25C-NBOMe) and 2-(4-iodo-2,5-dimethoxyphenyl)-N-[(2-methoxyphenyl)methyl]ethanamine (25I-NBOMe), have emerged in recreational drug markets. Here, we investigated the neuropharmacology of 25C-NBOMe and 25I-NBOMe in rats, as compared to their 2C analogs and the prototypical 5-HT2A/2C agonist 1-(4-iodo-2,5-dimethoxyphenyl)propan-2-amine (DOI). Compounds were tested in vitro using 5-HT2A receptor binding and calcium mobilization assays. For in vivo experiments, 25C-NBOMe (0.01-0.3â¯mg/kg), 25I-NBOMe (0.01-0.3â¯mg/kg), 2-(4-chloro-2,5-dimethoxyphenyl)ethanamine (2C-C) (0.1-3.0â¯mg/kg), 2-(4-iodo-2,5-dimethoxyphenyl)ethanamine (2C-I) (0.1-3.0â¯mg/kg) and DOI (0.03-1.0â¯mg/kg) were administered subcutaneously (sc) to male rats, and 5-HT2A-mediated behaviors were assessed. NBOMes displayed higher affinity for 5-HT2A receptors than their 2C counterparts but were substantially weaker in functional assays. 25C-NBOMe and 25I-NBOMe were much more potent at inducing wet dog shakes (WDS) and back muscle contractions (BMC) when compared to 2C-C and 2C-I. Pretreatment with the selective 5-HT2A antagonist (R)-(2,3-dimethoxyphenyl){1-[2-(4-fluorophenyl)ethyl]-4-piperidinyl}methanol (M100907) reversed behaviors produced by all agonists. Interestingly, binding affinities at the 5-HT2A receptor were significantly correlated with potencies to induce BMC but not WDS. Our findings show that NBOMes are highly potent 5-HT2A agonists in rats, similar to effects in mice, and consistent with the reported hallucinogenic effects in human users. This article is part of the Special Issue entitled 'Psychedelics: New Doors, Altered Perceptions'.
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Benzilaminas/farmacologia , Dimetoxifeniletilamina/análogos & derivados , Alucinógenos/farmacologia , Fenetilaminas/farmacologia , Serotoninérgicos/farmacologia , Animais , Músculos do Dorso/efeitos dos fármacos , Músculos do Dorso/fisiopatologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Dimetoxifeniletilamina/farmacologia , Relação Dose-Resposta a Droga , Fluorbenzenos/farmacologia , Células HEK293 , Movimentos da Cabeça/efeitos dos fármacos , Movimentos da Cabeça/fisiologia , Humanos , Masculino , Estrutura Molecular , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Piperidinas/farmacologia , Distribuição Aleatória , Ratos Sprague-Dawley , Receptor 5-HT2A de Serotonina/metabolismo , Receptor 5-HT2C de Serotonina/metabolismoRESUMO
3,4-Methylenedioxy-N-methylcathinone (methylone) is a new psychoactive substance and the ß-keto analog of 3,4-methylenedioxy-N-methylamphetamine (MDMA). It is well established that MDMA metabolism produces bioactive metabolites. Here we tested the hypothesis that methylone metabolism in rats can form bioactive metabolites. First, we examined the pharmacokinetics (PKs) of methylone and its metabolites after subcutaneous (sc) methylone administration (3, 6, 12 mg/kg) to male rats fitted with intravenous (iv) catheters for repeated blood sampling. Plasma specimens were assayed by liquid chromatography tandem mass spectrometry to quantify methylone and its phase I metabolites: 3,4-methylenedioxycathinone (MDC), 3,4-dihydroxy-N-methylcathinone (HHMC), and 4-hydroxy-3-methoxy-N-methylcathinone (HMMC). The biological activity of methylone and its metabolites was then compared using in vitro transporter assays and in vivo microdialysis in rat nucleus accumbens. For the PK study, we found that methylone and MDC peaked early (Tmax=15-45 min) and were short lived (t1/2=60-90 min), while HHMC and HMMC peaked later (Tmax=60-120 min) and persisted (t1/2=120-180 min). Area-under-the-curve values for methylone and MDC were greater than dose-proportional, suggesting non-linear accumulation. Methylone produced significant locomotor activation, which was correlated with plasma methylone, MDC, and HHMC concentrations. Methylone, MDC, and HHMC were substrate-type releasers at monoamine transporters as determined in vitro, but only methylone and MDC (1, 3 mg/kg, iv) produced significant elevations in brain extracellular dopamine and 5-HT in vivo. Our findings demonstrate that methylone is extensively metabolized in rats, but MDC is the only centrally active metabolite that could contribute to overall effects of the drug in vivo.