Paranoid delusional disorder follows social anxiety disorder in a long-term case series: evolutionary perspective.

Social anxiety disorder (SAD) patients may have self-referential ideas and share other cognitive processes with paranoid delusional disorder (PDD) patients. From an evolutionary perspective, SAD may derive from biologically instinctive social hierarchy ranking, thus causing an assumption of inferior social rank, and thus prompting concerns about mistreatment from those of perceived higher rank. This naturalistic longitudinal study followed four patients with initial SAD and later onset of PDD. These four patients show the same sequence of diagnosed SAD followed by diagnosed PDD, as is often retrospectively described by other PDD patients. Although antipsychotic medication improved psychotic symptoms in all patients, those who also had adjunctive serotonin-specific reuptake inhibitors for SAD had much more improvement in both psychosis and social functioning. From an evolutionary perspective, it can be conjectured that when conscious modulation of the SAD social rank instinct is diminished due to hypofrontality (common to many psychotic disorders), then unmodulated SAD can lead to paranoid delusional disorder, with prominent ideas of reference. Non-psychotic SAD may be prodromal or causal for PDD.

Resting-state fMRI is associated with trauma experiences, mood and psychosis in Afro-descendants with bipolar disorder and schizophrenia.

BACKGROUND: Bipolar disorder (BD) and schizophrenia (SCZ) may exhibit functional abnormalities in several brain areas, including the medial temporal and prefrontal cortex and hippocampus; however, a less explored topic is how brain connectivity is linked to premorbid trauma experiences and clinical features in non-Caucasian samples of SCZ and BD. METHODS: Sixty-two individuals with SCZ (n = 20), BD (n = 21), and healthy controls (HC, n = 21) from indigenous and African ethnicity were submitted to clinical screening (Di-PAD), traumata experiences (ETISR-SF), cognitive and functional MRI assessment. The item psychosis/hallucinations in SCZ patients showed a negative correlation with the global efficiency (GE) in the right dorsal attention network. The items mania, irritable mood, and racing thoughts in the Di-PAD scale had a significant negative correlation with the GE in the parietal right default mode network. CONCLUSIONS: Differences in the activation of specific networks were associated with earlier disease onset, history of physical abuse, and more severe psychotic and mood symptoms in SCZ and BD subjects of indigenous and black ethnicity. Findings provide further evidence on SZ and BD's brain connectivity disturbances, and their clinical significance, in non-Caucasian samples.

Co-developing a health promotion programme for indigenous youths in Brazil: A concept mapping report.

BACKGROUND: Latin America and the Caribbean Region are home to about 42 million Indigenous people, with about 900,000 living in Brazil. The little routinely collected population-level data from Indigenous communities in the region available shows stark inequities in health and well-being. There are 305 Indigenous ethnic groups, speaking 274 languages, spread across the remote national territory, who have endured long-lasting inequities related to poverty, poor health, and limited access to health care. Malnutrition and mental health are key concerns for young people. Building on our Indigenous communities-academic partnerships over the last two decades, we collaborated with young people from the Terena Indigenous ethnic group, village leaders, teachers, parents, and local health practitioners from the Polo Base (community health centres) to obtain their perspectives on important and feasible actions for a youth health promotion programme. METHODS: The report was conducted in the Tereré Village in Mato Grosso do Sul. Concept mapping, a participatory mixed method approach, was conducted in 7 workshops, 15 adults and 40 youths aged 9-17 years. Art-based concept mapping was used with 9 to 11 years old children (N = 20). Concept systems software was used to create concept maps, which were finalised during the workshops. Focused prompts related to factors that may influence the health and happiness of youths. The participatory method gave Terena youths a significant voice in shaping an agenda that can improve their health. RESULTS: Terena youths identified priority actions that clustered under 'Family', 'School', 'Education', 'Socio-economic circumstances', 'Respect' and 'Sport' in response to protecting happiness; and 'Nutrition pattern', 'Physical activity', 'Local environment', and 'Well-being' in response to having a healthy body. Through the participatory lens of concept mapping, youths articulated the interconnectedness of priority actions across these clusters such that behaviours (e.g. Nutrition pattern, drinking water, physical activity) and aspirations (being able to read, to have a good job) were recognised to be dependent on a wider ecology of factors (e.g. loss of eco-systems, parent-child relationships, student- teacher relationships, parental unemployment). In response to developing youth health, Terena adults suggested priority actions that clustered under 'Relationships', 'Health issues', 'Prevention at Polo Base', 'Access to health care', 'Communication with young people', 'Community life', 'Raising awareness' and 'School support'. Their priorities reflected the need for structural transformative actions (e.g. Polo Base and school staff working together) and for embedding actions to protect Indigenous culture (e.g. integrating their cultural knowledge into training programmes). CONCLUSIONS: Concept maps of Indigenous youths emphasised the need for a health promotion programme that engages with the structural and social determinants of health to protect their happiness and health, whilst those of adults emphasised the need to address specific health issues through preventative care via a school-Polo Base collaboration. Investment in a co-developed school-Polo-Base health promotion programme, with intersectoral engagement, has potential for making Indigenous health systems responsive to the inequalities of youth health, to yield dividends for healthy ageing trajectories as well as for the health of the next generation.

A randomized, naturalistic, parallel-group study for the long-term treatment of panic disorder with clonazepam or paroxetine.

This long-term extension of an 8-week randomized, naturalistic study in patients with panic disorder with or without agoraphobia compared the efficacy and safety of clonazepam (n = 47) and paroxetine (n = 37) over a 3-year total treatment duration. Target doses for all patients were 2 mg/d clonazepam and 40 mg/d paroxetine (both taken at bedtime). This study reports data from the long-term period (34 months), following the initial 8-week treatment phase. Thus, total treatment duration was 36 months. Patients with a good primary outcome during acute treatment continued monotherapy with clonazepam or paroxetine, but patients with partial primary treatment success were switched to the combination therapy. At initiation of the long-term study, the mean doses of clonazepam and paroxetine were 1.9 (SD, 0.30) and 38.4 (SD, 3.74) mg/d, respectively. These doses were maintained until month 36 (clonazepam 1.9 [SD, 0.29] mg/d and paroxetine 38.2 [SD, 3.87] mg/d). Long-term treatment with clonazepam led to a small but significantly better Clinical Global Impression (CGI)-Improvement rating than treatment with paroxetine (mean difference: CGI-Severity scale -3.48 vs -3.24, respectively, P = 0.02; CGI-Improvement scale 1.06 vs 1.11, respectively, P = 0.04). Both treatments similarly reduced the number of panic attacks and severity of anxiety. Patients treated with clonazepam had significantly fewer adverse events than those treated with paroxetine (28.9% vs 70.6%, P < 0.001). The efficacy of clonazepam and paroxetine for the treatment of panic disorder was maintained over the long-term course. There was a significant advantage with clonazepam over paroxetine with respect to the frequency and nature of adverse events.

Neural correlates of negative and disease-specific emotional stimuli in panic disorder: a functional magnetic resonance imaging study.

OBJECTIVE: Decades of research have highlighted the involvement of the prefrontal cortex, anterior cingulated cortex, and limbic areas (amygdala) in panic disorder (PD). However, little attention has been given specifically to the inferior frontal gyrus. The current study aimed to investigate the neural substrates, including the inferior frontal gyrus, of both panic-related and negative conditions among individuals with PD and healthy controls. METHODS: We examined 13 medication-free PD patients and 14 healthy controls with functional magnetic resonance imaging (fMRI) during exposure to negative and neutral pictures and a set of specific panic-related pictures. RESULTS: Subtraction between the conditions indicated activation of the left amygdala region and the right inferior frontal gyrus in PD patients during the specific panic-related condition, whereas the left amygdalar region and left inferior frontal gyrus were activated during the negative condition in controls. CONCLUSION: These results suggest that in patients with PD, a prominent bottom-up process is involved in specific panic-related conditions, which might be associated with weak modulation of the left frontal area. These data add to our current understanding of the neural correlates of PD and can contribute to future clinical interventions targeting the functional reestablishment of these regions.

Tapering clonazepam in patients with panic disorder after at least 3 years of treatment.

High-potency benzodiazepines, such as clonazepam, are frequently used in the treatment of panic disorder (PD) because of their rapid onset of action and good tolerability. However, there is concern about their potential to cause withdrawal symptoms. We aimed to develop a protocol for safely tapering off clonazepam in patients with PD who had been receiving treatment for at least 3 years. A specific scale for judging withdrawal was also developed, the Composite Benzodiazepine Discontinuation Symptom Scale. We selected 73 patients with PD who had been asymptomatic for at least 1 year and who wished to discontinue the medication. The trial consisted of a 4-month period of tapering and an 8-month follow-up period. The dosage of clonazepam was decreased by 0.5 mg per 2-week period until 1 mg per day was reached, followed by a decrease of 0.25 mg per week. The mean dosage at the start of tapering was 2.7 +/- 1.2 mg/d. In total, 51 (68.9%) of the patients were free of the medication after the 4 months of tapering according to the protocol, and 19 (26.0%) of the patients needed another 3 months to be free of medication. Clonazepam discontinuation symptoms were mostly mild and included mainly: anxiety, shaking/trembling/tremor, nausea/vomiting, insomnia/nightmares, excessive sweating, tachycardia/palpitations, headache, weakness, and muscle aches. The improvement in PD and general well-being was maintained during both the taper and follow-up phases. Clonazepam can be successfully discontinued without any major withdrawal symptoms if the dose is reduced gradually. We recommend reducing the dosage of clonazepam after intermediate-term use by 0.25 mg/wk.

Double-blind comparison of 30 and 60 mg tranylcypromine daily in patients with panic disorder comorbid with social anxiety disorder.

Our objective was to explore the dose-response relationship in patients with panic disorder and social anxiety disorder comorbidity (DSM-IV). After 1 week of no-drug washout, 36 such patients were assigned to a double-blind controlled comparison of the effects of 30 mg and 60 mg of tranylcypromine, and were followed up for 12 weeks. The main instrument used to measure the number of panic attacks was the Sheehan Panic and Anticipatory Anxiety Scale. The primary outcome measure for social anxiety disorder symptoms was the mean change from baseline in the Liebowitz Social Anxiety Scale (LSAS). After 12 weeks of treatment, panic attacks were reduced 69.6% from baseline in the 30-mg group (n=19) compared with a 74.8% reduction in the 60-mg group (n=17). Twelve patients (70.6%) of the higher dose group and 14 patients (68.4%) of the lower dose were completely free of panic attacks. There was no difference in efficacy between the tranylcypromine groups in the panic disorder symptoms. The 60-mg dose was more efficacious as measured by the LSAS scores, showing a significant difference in relation to the lower group. Mean change from baseline in LSAS total score (mean+/-SD) for 30-mg group was 17.9+/-14.7 and for the 60-mg group was 35.0+/-14.8. The social anxiety symptom scale showed a two-fold greater change with the 60-mg dose, and the 30-mg dose group could be considered the equivalent of a placebo control group. Tranylcypromine--60 mg daily--was found effective in the treatment of panic disorder and social anxiety disorder comorbidity.

Polygenic risk for anxiety influences anxiety comorbidity and suicidal behavior in bipolar disorder.

Bipolar disorder is often comorbid with anxiety, which is itself associated with poorer clinical outcomes, including suicide. A better etiologic understanding of this comorbidity could inform diagnosis and treatment. The present study aims to test whether comorbid anxiety in bipolar disorder reflects shared genetic risk factors. We also sought to assess the contribution of genetic risk for anxiety to suicide attempts in bipolar disorder. Polygenic risk scores (PRS) were calculated from published genome-wide association studies of samples of controls and cases with anxiety (n = 83,566) or bipolar disorder (n = 51,710), then scored in independent target samples (total n = 3369) of individuals with bipolar disorder who reported or denied lifetime anxiety disorders or suicidal attempts in research interviews. Participants were recruited from clinical and nonclinical settings and genotyped for common genetic variants. The results show that polygenic risk for anxiety was associated with comorbid anxiety disorders and suicide attempts in bipolar disorder, while polygenic risk for bipolar disorder was not associated with any of these variables. Our findings point out that comorbid anxiety disorders in bipolar disorder reflect a dual burden of bipolar and anxiety-related genes; the latter may also contribute to suicide attempts. Clinical care that recognizes and addresses this dual burden may help improve outcomes in people living with comorbid bipolar and anxiety disorders.

Panic disorder and social anxiety disorder subtypes in a caffeine challenge test.

Studies have demonstrated the vulnerability of anxiety disorder patients to challenge tests. Our aim was to observe if panic disorder (PD) patients and generalized social anxiety disorder (GSAD) and performance social anxiety disorder (PSAD) patients respond in a similar way to the induction of anxiety symptoms and panic attacks by an oral caffeine challenge test. We compared 28 PD patients, 25 GSAD patients, 19 PSAD, and 26 control subjects after a 480-mg caffeine test. The patients had not received psychotropic drugs for at least a 4-week period. In a randomized double-blind experiment performed in two occasions 7 days apart, 480 mg of caffeine and a caffeine-free solution were administered and anxiety scales were administered before and after each test. A panic attack was induced in 17 (60.7%) PD patients, 4 (16.0%) GSAD patients, and 10 (52.6%) PSAD patients, during the caffeine test. None of the control subjects had a panic attack after the caffeine intake. Neither patients nor any control subject had a panic attack after drinking the caffeine-free solution. Our data suggest that there is an association between PD and PSAD hyperreactivity to an oral caffeine challenge test. The PD and PSAD patients had a higher number of induced panic attacks, some specific anxiety symptoms, and a more severe anxiety response than GSAD patients and normal volunteers.

Corrigendum: Early Trauma and Cognitive Functions of Patients With Schizophrenia.

[This corrects the article DOI: 10.3389/fpsyt.2019.00261.].

Early Trauma and Cognitive Functions of Patients With Schizophrenia.

Aim: The following work aims to investigate the putative correlation between early trauma and cognitive functions, as well as psychotic symptoms and cognitive functions, in individuals diagnosed with schizophrenia. Methods: A quantitative assessment was performed with 20 individuals diagnosed with schizophrenia according to the 5th edition of the Diagnostic and Statistical Manual (DSM-5) criteria and who were in ongoing outpatient treatment in Psychosocial Care Centres in Brazil. Clinical measurements comprised a semistructured clinical interview, a screening questionnaire for common mental disorders, the Positive and Negative Syndrome Scale (PANSS), and the Early Trauma Inventory Self-Report-Short Form (ETISR-SF). Cognitive assessment included Beta III test, Concentrated Attention (CA) test, Color Trails Test (CTT), and Visual Face Memory (VFM) test. Results: Age-adjusted analysis showed a negative correlation between early trauma and visual memory performance (r = -0.585, p = 0.007) and negative symptoms and attention performance (r = -0.715, p = 0.000). Conclusion: Although a cause-effect relationship cannot be firmly stated, an association between early trauma experience and cognitive impairment such as visual memory, as well as a relationship between negative symptoms and attention domains, is suggested by our preliminary findings. Future studies with larger sample sizes and prospective design will clarify the long-term effects of early exposure to trauma and its clinical meaning in terms of developing psychotic-related illness.

Traumatic experiences and cognitive profiles of schizophrenia cases influenced by the BDNF Val66met polymorphism.

The association of early trauma exposure with current cognition was examined in a research series of 56 schizophrenia cases with respect to the BDNF Val66Met polymorphism (rs6265, Val66Val, Val66Met, Met66Met), as met allele carriers have reduced neurotrophic activity. The Perceptual Organization Index had a significant negative correlation with trauma exposures only in met carriers, including early physical abuse, general trauma after age 18 years, and physical abuse. Within the Val66Val subgroup, there were no significant correlations between WAIS indices and traumatic experiences.

A caffeine challenge test in panic disorder patients, their healthy first-degree relatives, and healthy controls.

Our aim was to observe the induction of anxiety symptoms and panic attacks by a caffeine challenge test in panic disorder (PD) patients (DSM-IV) and their healthy first-degree relatives. We randomly selected 25 PD patients, 27 healthy first-degree relatives of probands with PD, and 22 healthy volunteers with no family history of PD. In a randomized double-blind experiment performed over two occasions 7 days apart, 480 mg caffeine and a caffeine-free solution were administered in a coffee form. Using specific panic attack criteria, 52.0% (n=13) PD patients, 40.7% (n=11) first-degree relatives (chi2=1.81, df=1, P=0.179), and none of the control subjects had a panic attack after the test (chi2=51.7, df=2, P<0.001). In this caffeine challenge test, PD patients and their first-degree relatives were more sensitive than healthy volunteers to the panic attack symptoms but less sensitive to headache, increase in blood pressure, and insomnia. Our data suggest that there is an association between panic attacks after the intake of 480 mg of caffeine in PD patients and their first-degree relatives. There is a clear differentiation of PD patients and their first-degree relatives by a caffeine test from the healthy group.

Demographic and clinical features of panic disorder comorbid with bipolar I disorder: a 3-year retrospective study.

BACKGROUND: Mood disorders are considered related to anxiety disorders and their association may determine clinical course and prognosis. We aimed to describe with retrospective methodology the demographic, clinical, and treatment features in a group of panic disorder comorbid with bipolar I disorder (PD-BI) patients who were been treated for at least 3 year-period and compare them with bipolar I (BI) patients who were treated during the same period. METHOD: We compared the demographic and clinical data of 26 PD-BI, 28 BI, and 25 panic disorder (PD) outpatients without history of comorbidity with mood disorder were diagnosed and treated for at least 3 years in the Federal University of Rio de Janeiro. RESULTS: PD group have a higher educational level, are more married, and are more economically active. In the PD-BI and BI patients the disorders started earlier. They also turn out to have an equivalent pattern in the presence of drug abuse episodes, moderate or severe depressive episodes, psychotic episodes, suicide attempts, maniac episodes, mixed episodes, use of fewer days of antidepressants and benzodiazepines, and use of more days of antipsychotics and mood stabilizers. The PD-BI and the BI groups had a higher frequency of depressive episodes and psychotic episodes. LIMITATIONS: It is a retrospective data description based on a naturalistic treatment. The sample has a small size and the some data could be different in a large sample. CONCLUSION: PD-BI patients have demographic, clinical and therapeutic features similar to BI and the data support its validation as a special severe bipolar I disorder subgroup.

Panic disorder respiratory subtype: a comparison between responses to hyperventilation and CO2 challenge tests.

In this study 117 panic disorder patients were divided into a respiratory subtype group and a non-respiratory subtype group. The respiratory subtype patients were observed to be more sensitive to the 35% CO(2) inhalation challenge test and the hyperventilation test than the non-respiratory subtype patients.

Early trauma, attachment experiences and comorbidities in schizophrenia.

OBJECTIVE: To evaluate attachment patterns in subjects with schizophrenia and their relationships to early traumatic events, psychotic symptoms and comorbidities. METHODS: Twenty patients diagnosed with schizophrenia according to criteria from the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) underwent retrospective symptom assessment and careful assessment of the number and manner of childhood caregiver changes. The Diagnostic Interview for Psychosis and Affective Disorders (DI-PAD) was used to assess symptoms related to schizophrenia (positive and negative symptoms), depression and mania. Anxiety disorder comorbidities were assessed by the Liebowitz Social Anxiety Scale (LSAS), Yale-Brown Obsessions and Compulsions Scale (Y-BOCS) and Panic and Schizophrenia Interview (PaSI). Experience in Close Relationships - Relationship Structures (ECR-RS) and Early Trauma Inventory Self Report-Short Form (ETISR-SF) were used to assess attachment patterns and traumatic history, respectively. RESULTS: Moderate and significant correlations between attachment patterns and early trauma showed that greater severity of anxious attachment was predicted by a higher frequency of total early traumas (Spearman ρ = 0.446, p = 0.04), mainly general traumas (ρ = 0.526, p = 0.017; including parental illness and separation, as well as natural disaster and serious accidents). Among the correlations between early trauma and comorbid symptoms, panic attacks occurring before the onset of schizophrenia showed significant and positive correlations with ETISR-SF total scores and the sexual trauma subscale. CONCLUSION: Children with an unstable early emotional life are more vulnerable to the development of psychopathology, such as panic anxiety symptoms. Traumatic events may also predict later schizophrenia.

Rare missense coding variants in oxytocin receptor (OXTR) in schizophrenia cases are associated with early trauma exposure, cognition and emotional processing.

BACKGROUND: Oxytocin is a peptide hormone that influences the integration of social cognition with behavior and affect regulation. Oxytocin also prominently directs the transition of neuronal GABA neurotransmission from excitatory to inhibitory after birth. The oxytocin receptor (OXTR) is linked to schizophrenia, a heterogeneous syndrome. Relationships of OXTR polymorphisms with specific clinical features could aid in evaluating any role of oxytocin in the pathogenesis of schizophrenia. METHOD: Schizophrenia cases with rare missense coding OXTR single nucleotide variants (SNVs) were identified from a well-characterized sample of cases and controls who were assessed for symptoms, cognition and early life trauma. RESULTS: Five of 48 cases showed rare OXTR variants. Compared to the other cases they had less severe negative symptoms (deficits in emotional expression and motivation) and less severe general psychopathology scores (depression and anxiety). They demonstrated lower nonverbal (performance) than verbal intelligence due to deficient perceptual organization and slow processing speed. They also reported greater early trauma exposure (physical and sexual abuse and emotional trauma). CONCLUSION: Cases carrying rare OXTR SNVs had less negative and affective symptoms than other cases, but similar psychotic symptoms, along with specific cognitive deficits. The clinical characterization of these cases occurred in association with environmental exposure to early trauma, especially sexual abuse, which may have influenced the expression of schizophrenia in subjects harboring specific SNVs in the OXTR.

Personality traits spectrum in panic disorder and major depression.

OBJECTIVE: Our aim was to identify the personality traits in patients with panics disorder, major depression and with both disorders (comorbidity). METHOD: Diagnoses were made with the Structured Clinical Interview for DSM-IV before the treatment, and the personality evaluation with the Maudsley Personality Inventory was made during the follow-up. Four groups were analyzed: a control group (n = 30), a major depression without panic disorder group (n = 45); a panic disorder without major depression group (n = 56) and a comorbidity group (n = 21), with major depression and panic disorder, simultaneously. RESULTS: All disorder groups had significantly higher neuroticism means when compared to the control group. The highest mean was in the comorbidity group, followed by the major depression group and the panic disorder group. The difference of neuroticism means between the comorbidity group and the panic disorder group also reached statistical significance. The lowest extraversion mean was in the comorbidity group, followed by the major depression group, the panic disorder group, and the control group. Compared to normal controls, extraversion was significantly low in the comorbidity and major depression groups. CONCLUSION: In our sample, there was a continuum of personality traits between panic disorder and major depression and, the co-occurrence of these disorders was associated with accentuated personality traits.

Effect of Heteropterys aphrodisiaca on Anxiety and Male Exposure of Female Mice with Advanced Age.

BACKGROUND: Effect of Heteropterys aphrodisiaca (dog-node) on anxiety and function of adult female wistar mice. The project is an experiment with the use of H. aphrodisiac root extract, in order to observe the frequency of sexual exposure of females exposed to the extract, quantify the effect of the extract on the concentration of total testosterone and observe the anxiety levels of the animals exposed. Results will be measured with the laboratory testosterone test and LCE and CA tests. METHODS: In preparation of the extract, the root was oven dried at 40°C and diluted in alcohol extract (100g of root for 1 liter of alcohol) and lyophilized. 40 adult female mice were enrolled, separated in control group (placebo) and treatment group (50 mg/kg/day) for 15, 30, 45 and 60 days. At each period, hormonal testosterone and anxiety levels by the Elevated-Cross Labyrinth (ECL) tests and Open Camp (CA) were measured in 10 animals that were later euthanized (SBNeC). RESULTS: The results showed an improvement in the decrease of anxiety, as shown in the variables of number of open arm entries, time on the same side of the field, less avoidance and leakage. However, it appears that the time of exposure to the extract does not result in increased benefit, with possible decline of effect after 45 days of use. CONCLUSION: With this performed experiment with the "no-de-cachorro" extract, it was possible to understand a little more how this root can act in relation to anxiety, as predicted by the pharmacology that validates the animal models; anxiolytic components decrease anxiety-related behaviors, as shown in the variables of entry numbers in the open arm, time on the same side of the field, less avoidance and escape. However, it seems that the time of exposure to the extract does not modify the performance in the tests, observing until an apparent exhaustion of the anxiolytic action, which evidences the need for more specific studies on the possible effects of the extract.

Role of N-Arachidonoyl-Serotonin (AA-5-HT) in Sleep-Wake Cycle Architecture, Sleep Homeostasis, and Neurotransmitters Regulation.

The endocannabinoid system comprises several molecular entities such as endogenous ligands [anandamide (AEA) and 2-arachidonoylglycerol (2-AG)], receptors (CB1 and CB2), enzymes such as [fatty acid amide hydrolase (FAHH) and monoacylglycerol lipase (MAGL)], as well as the anandamide membrane transporter. Although the role of this complex neurobiological system in the sleep-wake cycle modulation has been studied, the contribution of the blocker of FAAH/transient receptor potential cation channel subfamily V member 1 (TRPV1), N-arachidonoyl-serotonin (AA-5-HT) in sleep has not been investigated. Thus, in the present study, varying doses of AA-5-HT (5, 10, or 20 mg/Kg, i.p.) injected at the beginning of the lights-on period of rats, caused no statistical changes in sleep patterns. However, similar pharmacological treatment given to animals at the beginning of the dark period decreased wakefulness (W) and increased slow wave sleep (SWS) as well as rapid eye movement sleep (REMS). Power spectra analysis of states of vigilance showed that injection of AA-5-HT during the lights-off period diminished alpha spectrum across alertness in a dose-dependent fashion. In opposition, delta power spectra was enhanced as well as theta spectrum, during SWS and REMS, respectively. Moreover, the highest dose of AA-5-HT decreased wake-related contents of neurotransmitters such as dopamine (DA), norepinephrine (NE), epinephrine (EP), serotonin (5-HT) whereas the levels of adenosine (AD) were enhanced. In addition, the sleep-inducing properties of AA-5-HT were confirmed since this compound blocked the increase in W caused by stimulants such as cannabidiol (CBD) or modafinil (MOD) during the lights-on period. Additionally, administration of AA-5-HT also prevented the enhancement in contents of DA, NE, EP, 5-HT and AD after CBD of MOD injection. Lastly, the role of AA-5-HT in sleep homeostasis was tested in animals that received either CBD or MOD after total sleep deprivation (TSD). The injection of CBD or MOD increased alertness during sleep rebound period after TSD. However, AA-5-HT blocked this effect by allowing animals to display an enhancement in sleep across sleep rebound period. Overall, our findings provide evidence that AA-5-HT is an important modulator of sleep, sleep homeostasis and neurotransmitter contents.