Panicolytic-like effects of environment enrichment on male mice threatened by Bothrops jararaca lancehead pit vipers.

Environment enrichment (EE) is a well-known eustress model showing beneficial effects in different psychiatric diseases, but its positive properties in panic disorders are not yet established. The confrontation between prey and predator in complex arenas has been validated as a putative panic attack model. The principal aim of this work was to investigate the role of the EE on panic-like defensive responses elicited by mice threatened by venomous snakes. After 6 weeks of exposure either to an enriched or standard environments, 36 male mice were habituated in a complex polygonal arena for snakes containing an artificial burrow and elevated platforms for escape. The animals were confronted by Bothrops jararaca for 5 min, and the following antipredatory responses were recorded: defensive attention, stretched attend posture, flat back approach, prey versus predator interaction, oriented escape behavior, time spent in a safe place, and number of crossings. Mice threatened by snakes displayed several antipredatory reactions as compared to the exploratory behavior of those animals submitted to a nonthreatening situation (toy snake) in the same environment. Notably, EE causes anxiolytic- and panicolytic-like effects significantly decreasing the defensive attention and time spent in safe places and significantly increasing both prey versus predator interaction and exploratory behavior. In conclusion, our data demonstrate that EE can alter the processing of fear modulation regarding both anxiety- and panic-like responses in a dangerous condition, significantly modifying the decision-making defensive strategy.

Premature burial.

The fear of being buried alive or taphophobia remains a significant concern for a number of individuals. In previous centuries however, reports of live burials were frequently promulgated in the media fostering an industry focused around the manufacturing and selling of security coffins which either facilitated egress or enabled the recently buried to alert those on the surface to their plight. Holding mortuaries with resuscitation facilities were also established mainly in Continental Europe to permit close observation of the recently deceased until definitive signs of putrefaction had developed. Underpinning much of this panic was the inability of medical practitioners to definitely diagnose death. Although still a rare possibility, mainly in situations where qualified medical personnel are not available, the likelihood of alive burial is nowadays fortunately rare.

Changes in General and Virus-Specific Anxiety During the Spread of COVID-19 in Israel: A 7-Wave Longitudinal Study.

We compared 3 hypothetical trajectories of change in both general and coronavirus disease 2019 (COVID-19)-specific anxiety during the first wave of the spread in the state of Israel: panic (very high anxiety, either from the outset or rapidly increasing), complacency (stable and low anxiety), and threat-sensitive (a moderate, linear increase compatible with the increase in threat). A representative sample of 1,018 Jewish-Israeli adults was recruited online. A baseline assessment commenced 2 days prior to the identification of the first case, followed by 6 weekly assessments. Latent mixture modeling analyses revealed the presence of 3 trajectories: 1) "threat-sensitivity" (29% and 66%, for general and virus-specific anxiety, respectively), 2) panic (12% and 25%), and 3) complacency (29% and 9%). For general anxiety only, a fourth class representing a stable mid-level anxiety was identified ("balanced": 30%). For general anxiety, women and the initially anxious-both generally and specifically from the spread of the virus-were more likely to belong to the panic class. Men and older participants were more likely to belong to the complacency class. Findings indicate a marked heterogeneity in anxiety responses to the first wave of the spread of COVID-19, including a large group evincing a "balanced" response.

Panic-like responses of female Wistar rats confronted by Bothrops alternatus pit vipers, or exposure to acute hypoxia: Effect of oestrous cycle.

Anxiety-related diseases are more than twice as common in women than in men, and in women, symptoms may be exacerbated during the late luteal phase of the menstrual cycle. Despite this, most research into the underlying mechanisms, which drives drug development, have been carried out using male animals. In an effort to redress this imbalance, we compared responses of male and female Wistar rats during exposure to two unconditioned threatening stimuli that evoke panic-related defensive behaviours: confrontation with a predator (Bothrops alternatus) and acute exposure to hypoxia (7% O2 ). Threatened by venomous snake, male and female rats initially displayed defensive attention, risk assessment, and cautious interaction with the snake, progressing to defensive immobility to overt escape. Both males and females displayed higher levels of risk assessment but less interaction with the predator. They also spent more time in the burrow, displaying inhibitory avoidance, and more time engaged in defensive attention, and non-oriented escape behaviour. In females, anxiety-like behaviour was most pronounced in the oestrous and proestrus phases whereas panic-like behaviour was more pronounced during the dioestrus phase, particularly during late dioestrus. Acute hypoxia evoked panic-like behaviour (undirected jumping) in both sexes, but in females, responsiveness in late dioestrus was significantly greater than at other stages of the cycle. The results reveal that females respond in a qualitatively similar manner to males during exposure to naturally occurring threatening stimuli, but the responses of females is oestrous cycle dependent with a significant exacerbation of panic-like behaviour in the late dioestrus phase.

Comparison of Sodium Lactate Infusion and Carbon Dioxide Inhalation Panic Provocation Tests: A Meta-analysis.

BACKGROUND: Sodium lactate (NaL) infusion and carbon dioxide (CO2) inhalation are proven to provoke acute panic attacks (PAs) in patients with panic disorder (PD). A systematic literature search and meta-analysis were performed to compare the effect sizes of these methods. METHODS: Odds ratios were calculated for each of the original studies and were pooled using the random-effects model. RESULTS: Either NaL or CO2 provocations significantly increased the rates of PAs in individuals with PD compared to those in healthy controls. However, the effect size of NaL infusion (OR=25.13, 95% CI=15.48-40.80) was significantly greater than that of CO2 inhalation (OR=10.58, 95%CI=7.88-14.21). CONCLUSION: The evidence for the efficacy of the two panic provocation tests is very strong. Yet, the results support the superiority of NaL infusion over CO2 inhalation challenge as a panic provocation test. Thus, lactate seems a much stronger stimulus than CO2 for the brain suffocation detector.

Impacts of the COVID-19 pandemic on household food waste behaviour: A systematic review.

Food waste has adverse economic, social, and environmental impacts and increases the prevalence of food insecurity. Panic buying at the beginning of the COVID-19 outbreak raised serious concerns about a potential rise in food waste levels and higher pressure on waste management systems. This article aims to investigate the impact of COVID-19 on food waste behaviour and the extent to which it occurs using the systematic review method. A total of 38 articles were identified and reviewed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The findings showed that the COVID-19 pandemic led to reductions in household food waste in most countries. Several changes in shopping and cooking behaviours, food consumption, and managing inventory and leftovers have occurred due to COVID-19. Based on these insights, we predicted that some desirable food-management habits would be retained, and others would roll back in the post-COVID-19 world. The review contributes to the food waste literature by offering a comprehensive overview of behavioural changes during the COVID-19 pandemic and future research directions.

Determinants of the decision to build up excessive food stocks in the COVID-19 crisis.

In 2020, the first COVID-19 lockdowns resulted in food panic buying and excessive food stockpiling across many countries around the world. Many governments recommend keeping emergency food stocks for three to ten days for times of potential shortages in food supply. Based on data from an online survey conducted among Swiss inhabitants, we investigated the effect of knowledge level and stockpiling behaviour according to governmental stockpiling recommendations in normal times on the decision to build up more food stocks than usual during the first lockdown in 2020. For this purpose, we applied a combination of latent class analysis and logistic regression. Latent classes were constructed based on knowledge level and stockpiling behaviour according to governmental stockpiling recommendations in normal times. Subsequently, the information on class membership was used as predictor of the decision to excessively stockpile food during the first lockdown. The variable "class membership" revealed that respondents with a low knowledge level and food stocks below governmental recommendations in normal times had a 7.6 percentage points lower probability of excessively stockpiling food during the first lockdown than respondents with a high knowledge level and recommended food stocks in normal times. Excessive stockpiling was additionally driven by the worry that certain food products would disappear from the supermarket shelves entirely or would be in short supply. Moreover, regression results revealed that respondents who reduced their shopping frequency during the first lockdown in 2020 showed a higher probability of building up more food stocks than usual. Our findings are crucial for food suppliers and policymakers to understand the drivers of panic buying and to prevent this phenomenon in future crises.

Panic results in unique molecular and network changes in the amygdala that facilitate fear responses.

Recurrent panic attacks (PAs) are a common feature of panic disorder (PD) and post-traumatic stress disorder (PTSD). Several distinct brain regions are involved in the regulation of panic responses, such as perifornical hypothalamus (PeF), periaqueductal gray, amygdala and frontal cortex. We have previously shown that inhibition of GABA synthesis in the PeF produces panic-vulnerable rats. Here, we investigate the mechanisms by which a panic-vulnerable state could lead to persistent fear. We first show that optogenetic activation of glutamatergic terminals from the PeF to the basolateral amygdala (BLA) enhanced the acquisition, delayed the extinction and induced the persistence of fear responses 3 weeks later, confirming a functional PeF-amygdala pathway involved in fear learning. Similar to optogenetic activation of PeF, panic-prone rats also exhibited delayed extinction. Next, we demonstrate that panic-prone rats had altered inhibitory and enhanced excitatory synaptic transmission of the principal neurons, and reduced protein levels of metabotropic glutamate type 2 receptor (mGluR2) in the BLA. Application of an mGluR2-positive allosteric modulator (PAM) reduced glutamate neurotransmission in the BLA slices from panic-prone rats. Treating panic-prone rats with mGluR2 PAM blocked sodium lactate (NaLac)-induced panic responses and normalized fear extinction deficits. Finally, in a subset of patients with comorbid PD, treatment with mGluR2 PAM resulted in complete remission of panic symptoms. These data demonstrate that a panic-prone state leads to specific reduction in mGluR2 function within the amygdala network and facilitates fear, and mGluR2 PAMs could be a targeted treatment for panic symptoms in PD and PTSD patients.

Panic buying in times of coronavirus (COVID-19): Extending the theory of planned behavior to understand the stockpiling of nonperishable food in Germany.

At the onset of the coronavirus pandemic, sales of nonperishable food drastically increased in Germany. Reports of hoarding and panic buying flooded the media. To identify the drivers of the increased sales of these products, we carried out an online survey with n = 495 people living in Germany. We followed a concurrent triangulation design. For the quantitative analysis, we extended the theory of planned behavior to identify possible reasons for stockpiling nonperishable food. The results suggest that "attitude," "subjective norm," and the "fear of future unavailability" were main drivers of stockpiling behavior in our sample. Additionally, we analyzed answers to open questions capturing participants' own explanations of why they did or did not stockpile nonperishable food. By contrasting the results, we found that our qualitative results validate some of our quantitative findings but also deliver new insights. For instance, a key stated reason for stockpiling nonperishable food was to reduce shopping frequency.

Interactions between the nitrergic and the endocannabinoid system in rats exposed to the elevated T-maze.

OBJECTIVE: The aim of this study was to test the hypothesis that synthesis of nitric oxide (NO) and activation of CB1 receptors have opposite effects in a behavioural animal model of panic and anxiety. METHODS: To test the hypothesis, male Wistar rats were exposed to the elevated T-maze (ETM) model under the following treatments: L-Arginine (L-Arg) was administered before treatment with WIN55,212-2, a CB1 receptor agonist; AM251, a CB1 antagonist, was administered before treatment with L-Arg. All treatments were by intraperitoneal route. RESULTS: The CB1 receptor agonist, WIN55,212-2 (1 mg/kg), induced an anxiolytic-like effect, which was prevented by pretreatment with an ineffective dose of L-Arg (1 mg/kg). Administration of AM251 (1 mg/kg), a CB1 antagonist before treatment with L-Arg (1 mg/kg) did not produce anxiogenic-like responses. CONCLUSION: Altogether, this study suggests that the anxiolytic-like effect of cannabinoids may occur through modulation of NO signalling.

Internet Hospitals Help Prevent and Control the Epidemic of COVID-19 in China: Multicenter User Profiling Study.

BACKGROUND: During the spread of the novel coronavirus disease (COVID-19), internet hospitals in China were engaged with epidemic prevention and control, offering epidemic-related online services and medical support to the public. OBJECTIVE: The aim of this study is to explore the role of internet hospitals during the prevention and control of the COVID-19 outbreak in China. METHODS: Online epidemic-related consultations from multicenter internet hospitals in China during the COVID-19 epidemic were collected. The counselees were described and classified into seven type groups. Symptoms were recorded and compared with reported patients with COVID-19. Hypochondriacal suspicion and offline visit motivation were detected within each counselees' group to evaluate the social panic of the epidemic along with the consequent medical-seeking behaviors. The counselees' motivation and the doctors' recommendation for an offline visit were compared. Risk factors affecting the counselees' tendency of hypochondriacal suspicion and offline visit motivation were explored by logistic regression models. The epidemic prevention and control measures based on internet hospitals were listed, and the corresponding effects were discussed. RESULTS: A total of 4913 consultations were enrolled for analysis with the median age of the counselees at 28 years (IQR 22-33 years). There were 104 (2.12%) healthy counselees, 147 (2.99%) hypochondriacal counselees, 34 (0.69%) exposed counselees, 853 (17.36%) mildly suspicious counselees, 42 (0.85%) moderately suspicious counselees, 3550 (72.26%) highly suspicious counselees, and 183 (3.72%) severely suspicious counselees. A total of 94.20% (n=4628) of counselees had epidemic-related symptoms with a distribution similar to those of COVID-19. The hypochondriacal suspicion (n=2167, 44.11%) was common. The counselees' motivation and the doctors' recommendation for offline visits were inconsistent (P<.001) with a Cohen kappa score of 0.039, indicating improper medical-seeking behaviors. Adult counselees (odds ratio [OR]=1.816, P<.001) with epidemiological exposure (OR 7.568, P<.001), shortness of breath (OR 1.440, P=.001), diarrhea (OR 1.272, P=.04), and unrelated symptoms (OR 1.509, P<.001) were more likely to have hypochondriacal suspicion. Counselees with severe illnesses (OR 2.303, P<.001), fever (OR 1.660, P<.001), epidemiological exposure history (OR 1.440, P=.01), and hypochondriacal suspicion (OR 4.826, P<.001) were more likely to attempt an offline visit. Reattending counselees (OR 0.545, P=.002) were less motivated to go to the offline clinic. CONCLUSIONS: Internet hospitals can serve different types of epidemic counselees, offer essential medical supports to the public during the COVID-19 outbreak, reduce the social panic, promote social distancing, enhance the public's ability of self-protection, correct improper medical-seeking behaviors, reduce the chance of nosocomial cross-infection, and facilitate epidemiological screening, thus, playing an important role on preventing and controlling COVID-19.

Gone with the Wind.

OBJECTIVE: If the narrative of "coronavirus" has an underlying theme, it may perhaps for some be one of survival, whilst for others, the theme might be suffering. The recurring motif of survival has continued throughout history, yet for the first time the sum of all fears has amounted to a run on the bare essentials. This paper seeks to offer an alternative formulation of "panic buying," with references to literature, philosophy, and contemporary neurobiology. CONCLUSION: The bare essentials disappeared perhaps as part of some self-fulfilling prophecy: the supermarkets became bare because others inadvertently lead us to believe they would become bare. The contagion model of emotional propagation provides a psychological model of how "panic buying" by an individual might lead to the replication of panic in an observer. The Polyvagal Theory further informs us of how the threat posed by the pandemic primes our limbic system to perceive danger, and explains how witnessing others engaging in fight-flight responses might evoke a fearful affect in an observer. In the end, it is perhaps through Nietzsche's study of classical tragedy that we may find some meaning to the pandemic, allowing our collective lived experience to serve as a template for growth.

Mass Panic Disaster Management in COVID-19 Pandemic.

Coronavirus disease (COVID-19) pandemic occurred abruptly. It is an unexpected disaster. Uncertain treatment for this viral infection increases excessive anxiety, which does not occur only in one person but also in majority of people; therefore, it can create mass panic. Mass panic is a serious problem that must be immediately identified and managed. Mass panic management will reduce COVID-19 incidence.

NO in the dPAG modulates panic-like responses and ASIC1a expression in the prefrontal cortex and hippocampus in mice.

Panic disorder (PD) is a multifactorial neuropsychiatric disorder. Our previous study has demonstrated that the nitric oxide (NO) pathway and the acid-sensing ion channel 1a (ASIC1a) level in the dorsal midbrain periaqueductal gray (dPAG) are involved in the modulation of panic-like responses. In addition, the prefrontal cortex (PFC) and the hippocampus also play a role in panic-like responses. However, no studies have investigated the protein level of ASIC1a in the PFC and hippocampus in a mouse model of panic-like disorders after alteration of the NO pathway in the dPAG. We investigated the production of a panic attack with intra-dPAG injections of SNAP, an NO donor, and 7-NI, an nNOS inhibitor. Moreover, we measured ASIC1a protein levels in the PFC and hippocampus. The rat exposure test (RET) is frequently used as an animal model of panic. In our study, C57BL/6 mice received an intra-dPAG injection of SNAP or 7-NI before RET; neurobehavioral tests were then conducted, followed by mechanistic evaluation through western blot analysis in the PFC and hippocampus. An intra-dPAG infusion of SNAP significantly increased the panic-like effect, whereas treatment with 7-NI decreased fear behavior. Mice treated with SNAP/7-NI showed significantly increased/decreased ASIC1a expression in the PFC, and a decreasing/increasing trend in the hippocampus. The present study suggests that the NO pathway in the dPAG plays a key role in panic-like responses in mice confronted by a rat, further, NO intra-dPAG injection also modulates the ASIC1a expression levels in the PFC and hippocampus.

Select panicogenic drugs and stimuli induce consistent increases in tail skin flushes and decreases in core body temperature.

Panic attacks (PAs) are episodes of intense fear or discomfort that are accompanied by a variety of both psychological and somatic symptoms. Panic induction in preclinical models (e.g. rats) has largely been assayed through flight and avoidance behavioral tests and cardiorespiratory activity. Yet, the literature pertaining to PAs shows that thermal sensations (hot flushes/heat sensations and chills) are also a common symptom during PAs in humans. Considering that temperature alterations are objectively measurable in rodents, we hypothesized that select panicogenic drugs and stimuli induce consistent changes in thermoregulation related to hot flushes and chills. Specifically, we challenged male rats with intraperitoneal injections of the GABAergic inverse agonist FG-7142; the α2 adrenoceptor antagonist yohimbine; the serotonin agonist D-fenfluramine, and 20% CO2 (an interoceptive homeostatic challenge). We assayed core body temperature and tail skin temperature using implanted radiotelemetry probes and tail thermistors/thermal imaging camera, respectively, and found that all challenges elicited rapid, high-amplitude (~7-9°C) increase in tail skin temperature and delayed decreases (~1-3°C) in core body temperature. We propose that thermal sensations such as these may be an additional indicator of a panic response in rodents and humans, as these panicogenic compounds or stimuli are known to precipitate PAs in persons with panic disorder.

Longitudinal association between panic disorder and health care costs in older adults.

BACKGROUND: To analyze whether probable panic disorder (PD) is associated with health care costs in older age over time. METHODS: Data regarding individuals aged 65 and over were derived from two waves of the ESTHER cohort study (nt1 = 2,348, nt2 = 2,090). Probable PD was assessed using the panic screening module from the Patient Health Questionnaire. Health care costs were obtained through monetary valuation of self-reported health care use data. Fixed effects regressions analyzed the association between transitions in probable PD status and change in health care costs, while adjusting for potential confounders. RESULTS: On a descriptive level, study participants with a positive PD screening displayed higher three-month health care costs compared to those without (incremental costs: € 259 for t1 , € 1,544 for t2 ). Transitions in probable PD were associated with an approximate increase of 65% in outpatient health care costs (ß = 0.50, p < .05). There was no significant association between probable PD transition and change in any other cost category. CONCLUSIONS: Using longitudinal data, our results highlight the economic consequences of probable PD in older adults. Future research should address whether reducing PD in older adults may reduce the associated economic burden and analyze underlying mechanisms.

The Depression Treatment Cascade: Disparities by Alcohol Use, Drug Use, and Panic Symptoms Among Patients in Routine HIV Care in the United States.

Little is known about disparities in depression prevalence, treatment, and remission by psychiatric comorbidities and substance use among persons living with HIV (PLWH). We conducted a cross-sectional analysis in a large cohort of PLWH in routine care and analyzed conditional probabilities of having an indication for depression treatment, receiving treatment, receiving indicated treatment adjustments, and achieving remission, stratified by alcohol use, illicit drug use, and panic symptoms. Overall, 34.7% (95% CI 33.9-35.5%) of participants had an indication for depression treatment and of these, 55.3% (53.8-56.8%) were receiving antidepressants. Among patients receiving antidepressants, 33.0% (31.1-34.9%) had evidence of remitted depression. In a subsample of sites with antidepressant dosage data, only 8.8% (6.7-11.5%) of patients received an indicated treatment adjustment. Current drug users (45.8%, 95% CI 43.6-48.1%) and patients reporting full symptoms of panic disorder (75.0%, 95% CI 72.9-77.1%) were most likely to have an indication for antidepressant treatment, least likely to receive treatment given an indication (current drug use: 47.6%, 95% CI 44.3-51.0%; full panic symptoms: 50.8%, 95% CI 48.0-53.6%), or have evidence of remitted depression when treated (22.3%, 95% CI 18.5-26.6%; and 7.3%, 95% CI 5.5-9.6%, respectively). In a multivariable model, drug use and panic symptoms were independently associated with poorer outcomes along the depression treatment cascade. Few differences were evident by alcohol use. Current drug users were most likely to have an indication for depression treatment, but were least likely to be receiving treatment or to have remitted depression. These same disparities were even more starkly evident among patients with co-occurring symptoms of panic disorder compared to those without. Achieving improvements in the depression treatment cascade will likely require attention to substance use and psychiatric comorbidities.

The Role of Anxiety Sensitivity and Expectancy Manipulation on Panic-Like Response to the 35% CO2 Challenge in Healthy Subjects.

BACKGROUND: The 35% CO2 challenge is a well-established method triggering panic attacks under laboratory-controlled conditions. There is an ongoing debate whether single or the joined effects of the instructional set and anxiety sensitivity (AS) can alter the outcome of the challenge. OBJECTIVES: The present study investigated the effects of instruction manipulation and AS on panic-like response to the 35% CO2 challenge. METHODS: Eighty healthy subjects, with high or low levels of AS, were randomized into 4 groups based on standard/manipulated instructional sets as well as 35% CO2 mixture/room air inhalation. Subjects filled in the Visual Analogue Scale of Anxiety (VAAS), the Visual Analogue Scale of Fear (VAS-F), the VAS of Discomfort (VAS-D), and the Panic Symptom List (PSL). Blood pressure and heart rate were measured at pre- and posttest. RESULTS: Hierarchical multiple regression analyses showed greater psychological responses at VAAS, VAS-F, VAS-D, and PSL and higher systolic blood pressure under 35% CO2 challenge if compared to room air inhalation while instructional set and AS did not influence the response. CONCLUSIONS: The present study confirms that neither instructional test nor AS alter the outcome of the 35% CO2 challenge.

The Blockade of µ1- and κ-Opioid Receptors in the Inferior Colliculus Decreases the Expression of Panic Attack-Like Behaviours Induced by Chemical Stimulation of the Dorsal Midbrain.

BACKGROUND: Gamma-aminobutyric acid (GABA)ergic and opioid systems play a crucial role in the neural modulation of innate fear organised by the inferior colliculus (IC). In addition, the IC is rich in GABAergic fibres and opioid neurons, which are also connected to other mesencephalic structures, such as the superior colliculus and the substantia nigra. However, the contribution of distinct opioid receptors (ORs) in the IC during the elaboration and expression of innate fear and panic-like responses is unclear. The purpose of the present work was to investigate a possible integrated action exerted by ORs and the GABAA receptor-mediated system in the IC on panic-like responses. METHODS: The effect of the blockade of either µ1- or κ-ORs in the IC was evaluated in the unconditioned fear-induced responses elicited by GABAA antagonism with bicuculline. Microinjections of naloxonazine, a µ1-OR antagonist, or nor-binaltorphimine (nor-BNI), a κ-OR antagonist, were made into the IC, followed by intramesencephalic administration of the GABAA-receptor antagonist bicuculline. The defensive behaviours elicited by the treatments in the IC were quantitatively analysed, recording the number of escapes expressed as running (crossing), jumps, and rotations, over a 30-min period in a circular arena. The exploratory behaviour of rearing was also recorded. RESULTS: GABAA-receptor blockade with bicuculline in the IC increased defensive behaviours. However, pretreatment of the IC with higher doses (5 µg) of naloxonazine or nor-BNI followed by bicuculline resulted in a significant decrease in unconditioned fear-induced responses. CONCLUSIONS: These findings suggest a role played by µ1- and κ-OR-containing connexions and GABAA receptor-mediated neurotransmission on the organisation of panic attack-related responses elaborated by the IC neurons.

Preictal autonomic dynamics in psychogenic nonepileptic seizures.

OBJECTIVES: Psychogenic nonepileptic seizures (PNES) resemble seizures but are psychological in origin. The etiology of PNES remains poorly understood, yet several theories argue for the importance of autonomic dysregulation in its pathophysiology. We therefore conducted a retrospective study to investigate autonomic dynamics leading up to a seizure to inform their mechanistic relevance. METHODS: One hundred one patients with PNES and 45 patients with epileptic seizure (ES) were analyzed for preictal heart rate (HR) and respiratory rate (RR) at baseline and at minute intervals from 5 min to onset. RESULTS: Patients with PNES showed rising HR (p < 0.001, repeated-measures analysis of variance (ANOVA)) and rising RR (p = 0.012, repeated-measures ANOVA) from baseline to the onset of their seizures. Patients with ES did not exhibit significant preictal HR or RR increase. Patients with PNES had nonsignificantly higher preictal HR and RR than patients with ES. SIGNIFICANCE: Patients with PNES exhibit increasing autonomic arousal prior to seizure events unlike patients with epilepsy. This may reflect increasing levels of preictal anxiety, and future studies could study patients' subjective experiences of the preictal period, and more definitive measures of ventilation to see if this supported a model of PNES as "panic without panic".