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1,724 result(s) for "Fear - drug effects"
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LSD Acutely Impairs Fear Recognition and Enhances Emotional Empathy and Sociality
Lysergic acid diethylamide (LSD) is used recreationally and has been evaluated as an adjunct to psychotherapy to treat anxiety in patients with life-threatening illness. LSD is well-known to induce perceptual alterations, but unknown is whether LSD alters emotional processing in ways that can support psychotherapy. We investigated the acute effects of LSD on emotional processing using the Face Emotion Recognition Task (FERT) and Multifaceted Empathy Test (MET). The effects of LSD on social behavior were tested using the Social Value Orientation (SVO) test. Two similar placebo-controlled, double-blind, random-order, crossover studies were conducted using 100 μg LSD in 24 subjects and 200 μg LSD in 16 subjects. All of the subjects were healthy and mostly hallucinogen-naive 25- to 65-year-old volunteers (20 men, 20 women). LSD produced feelings of happiness, trust, closeness to others, enhanced explicit and implicit emotional empathy on the MET, and impaired the recognition of sad and fearful faces on the FERT. LSD enhanced the participants' desire to be with other people and increased their prosocial behavior on the SVO test. These effects of LSD on emotion processing and sociality may be useful for LSD-assisted psychotherapy.
Neural Underpinnings of Cortisol Effects on Fear Extinction
Extinction of conditioned fear embodies a crucial mechanism incorporated in exposure therapy. Clinical studies demonstrated that application of the stress hormone cortisol before exposure sessions facilitates exposure success, but the underlying neural correlates remain unknown. Context- and stimulus-dependent cortisol effects on extinction learning will be characterized in this study and tested in the extinction and in a new context. Forty healthy men participated in a 3-day fear conditioning experiment with fear acquisition in context A (day 1), extinction training in context B (day 2), and recall in context B and a new context C one week later (day 3). Hydrocortisone (30 mg) or placebo was given before extinction training. Blood-oxygen-level-dependent responses and skin conductance responses (SCRs) served as dependent measures. At the beginning of extinction training, cortisol reduced conditioned SCRs, diminished activation of the amygdala-hippocampal complex, and enhanced functional connectivity of the anterior parahippocampal gyrus with the ventromedial prefrontal cortex (vmPFC). After one week, the cortisol group showed increased hippocampal activation and connectivity to the vmPFC toward an extinguished stimulus and reduced insula activation toward a nonextinguished stimulus in the extinction context. However, this inhibitory cortisol effect did not extend to the new context. Taken together, cortisol reduced fear recall at the beginning of extinction and facilitated the consolidation of the extinction memory as evidenced by an inhibitory activation pattern one week later. The stress hormone exerted a critical impact on the amygdala-hippocampus-vmPFC network underlying fear and extinction memories. However, cortisol did not attenuate the context dependency of extinction.
Reduction in social anxiety after MDMA-assisted psychotherapy with autistic adults: a randomized, double-blind, placebo-controlled pilot study
Rationale Standard therapeutic approaches to reduce social anxiety in autistic adults have limited effectiveness. Since 3,4-methylenedioxymethamphetamine (MDMA)-assisted psychotherapy shows promise as a treatment for other anxiety disorders, a blinded, placebo-controlled pilot study was conducted. Objectives To explore feasibility and safety of MDMA-assisted psychotherapy for reduction of social fear and avoidance that are common in the autistic population. Methods Autistic adults with marked to very severe social anxiety were randomized to receive MDMA (75 to 125 mg, n  = 8) or inactive placebo (0 mg, n  = 4) during two 8-h psychotherapy sessions (experimental sessions) in a controlled clinical setting. Double-blinded experimental sessions were spaced approximately 1 month apart with 3 non-drug psychotherapy sessions following each. The primary outcome was change in Leibowitz Social Anxiety Scale (LSAS) Total scores from Baseline to one month after the second experimental session. Outcomes were measured again six months after the last experimental session. Results Improvement in LSAS scores from baseline to the primary endpoint was significantly greater for MDMA group compared to the placebo group ( P  = 0.037), and placebo-subtracted Cohen’s d effect size was very large ( d  = 1.4, CI − 0.074, 2.874). Change in LSAS scores from baseline to 6-month follow-up showed similar positive results ( P  = 0.036), with a Cohen’s d effect size of 1.1 (CI − 0.307, 2.527). Social anxiety remained the same or continued to improve slightly for most participants in the MDMA group after completing the active treatment phase. Conclusions This pilot trial demonstrated rapid and durable improvement in social anxiety symptoms in autistic adults following MDMA-assisted psychotherapy. Initial safety and efficacy outcomes support expansion of research into larger samples to further investigate this novel treatment for social anxiety. Trial registration clinicaltrials.gov identifier, NCT02008396
Short-term SSRI treatment normalises amygdala hyperactivity in depressed patients
Antidepressant drugs such as selective serotonin re-uptake inhibitors (SSRIs) remediate negative biases in emotional processing in depressed patients in both behavioural and neural outcome measures. However, it is not clear if these effects occur before, or as a consequence of, changes in clinical state. In the present study, we investigated the effects of short-term SSRI treatment in depressed patients on the neural response to fearful faces prior to clinical improvement in mood. Altogether, 42 unmedicated depressed patients received SSRI treatment (10 mg escitalopram daily) or placebo in a randomised, parallel-group design. The neural response to fearful and happy faces was measured on day 7 of treatment using functional magnetic resonance imaging. A group of healthy controls was imaged in the same way. Amygdala responses to fearful facial expressions were significantly greater in depressed patients compared to healthy controls. However, this response was normalised in patients receiving 7 days treatment with escitalopram. There was no significant difference in clinical depression ratings at 7 days between the escitalopram and placebo-treated patients. Our results suggest that short-term SSRI treatment in depressed patients remediates amygdala hyperactivity in response to negative emotional stimuli prior to clinical improvement in depressed mood. This supports the hypothesis that the clinical effects of antidepressant treatment may be mediated in part through early changes in emotional processing. Further studies will be needed to show if these early effects of antidepressant medication predict eventual clinical outcome.
D-Cycloserine Augmentation of Exposure Therapy for Post-Traumatic Stress Disorder: A Pilot Randomized Clinical Trial
Viewing post-traumatic stress disorder (PTSD) as a disorder of emotional learning, this study used a cognitive enhancer synergistically with virtual reality exposure (VRE) therapy for the treatment of PTSD. The main objective was to determine if a novel pharmacotherapy, D-cycloserine (DCS), enhanced the efficacy of the psychotherapy. Pre-clinical studies suggest that when fear extinction occurs during DCS administration, neuroplasticity may be enhanced. VRE therapy is a particularly promising format to test the hypothesis that DCS enhances extinction learning, as sensory fear cues are standardized across patients. In a pilot randomized, double-blind, placebo-controlled trial, 100 mg of DCS or placebo was administered 90 min before each weekly VRE session, to ensure peak plasma concentrations during the sessions in 25 patients with chronic PTSD. The primary outcome measure was the Clinician Administered PTSD Scale (CAPS). Secondary outcome measures included the Beck Depression Inventory-II and the State-Trait Anger Expression Inventory-2. Assessments occurred at pre-treatment, following sessions 3, 6, 10, post-treatment, and at 6 months. The difference in CAPS between the VRE-DCS (n=13) and VRE-placebo (n=12) groups increased over time beginning at 6 weeks, with medium to large between-group effect sizes immediately post-treatment and 6 months later (d=0.68 and d=1.13, respectively). A similar pattern was observed for depression, anger expression, and sleep. PTSD remission rates were significantly greater for the VRE-DCS group (46% vs 8% at post-treatment; 69% vs 17% at 6 months). Patients in the VRE-DCS group showed earlier and greater improvement in PTSD symptoms compared with the VRE-placebo group. These results suggest a promising new treatment for PTSD.
Blocking human fear memory with the matrix metalloproteinase inhibitor doxycycline
Learning to predict threat is a fundamental ability of many biological organisms, and a laboratory model for anxiety disorders. Interfering with such memories in humans would be of high clinical relevance. On the basis of studies in cell cultures and slice preparations, it is hypothesised that synaptic remodelling required for threat learning involves the extracellular enzyme matrix metalloproteinase (MMP) 9. However, in vivo evidence for this proposal is lacking. Here we investigate human Pavlovian fear conditioning under the blood–brain barrier crossing MMP inhibitor doxycyline in a pre-registered, randomised, double-blind, placebo-controlled trial. We find that recall of threat memory, measured with fear-potentiated startle 7 days after acquisition, is attenuated by ~60% in individuals who were under doxycycline during acquisition. This threat memory impairment is also reflected in increased behavioural surprise signals to the conditioned stimulus during subsequent re-learning, and already late during initial acquisition. Our findings support an emerging view that extracellular signalling pathways are crucially required for threat memory formation. Furthermore, they suggest novel pharmacological methods for primary prevention and treatment of posttraumatic stress disorder.
Single dose of l-dopa makes extinction memories context-independent and prevents the return of fear
Traumatic events can engender persistent excessive fear responses to trauma reminders that may return even after successful treatment. Extinction, the laboratory analog of behavior therapy, does not erase conditioned fear memories but generates competing, fear-inhibitory “extinction memories” that, however, are tied to the context in which extinction occurred. Accordingly, a dominance of fear over extinction memory expression—and, thus, return of fear—is often observed if extinguished fear stimuli are encountered outside the extinction (therapy) context. We show that postextinction administration of the dopamine precursor l -dopa makes extinction memories context-independent, thus strongly reducing the return of fear in both mice and humans. Reduced fear is accompanied by decreased amygdala and enhanced ventromedial prefrontal cortex activation in both species. In humans, ventromedial prefrontal cortex activity is predicted by enhanced resting-state functional coupling of the area with the dopaminergic midbrain during the postextinction consolidation phase. Our data suggest that dopamine-dependent boosting of extinction memory consolidation is a promising avenue to improving anxiety therapy.
Effects of intranasal oxytocin on fear extinction learning
Once a threat no longer exists, extinction of conditioned fear becomes adaptive in order to reduce allotted resources towards cues that no longer predict the threat. In anxiety and stress disorders, fear extinction learning may be affected. Animal findings suggest that the administration of oxytocin (OT) modulates extinction learning in a timepoint-dependent manner, facilitating extinction when administered prior to fear conditioning, but impairing it when administered prior to extinction learning. The aim of the present study was to examine if these findings translate into human research. Using a randomized, double-blind, placebo-controlled, 2-day fear conditioning and extinction learning design, behavioral (self-reported anxiety), physiological (skin conductance response), neuronal (task-based and resting-state functional magnetic resonance imaging), and hormonal (cortisol) data were collected from 124 naturally cycling (taking no hormonal contraceptives) healthy females. When administered prior to conditioning (Day 1), OT, similar to rodent findings, did not affect fear conditioning, but modulated the intrinsic functional connectivity of the anterior insula immediately after fear conditioning. In contrast to animal findings, OT impaired, not facilitated, extinction learning on the next day and increased anterior insula activity. When administered prior to extinction learning (day 2), OT increased the activity in the bilateral middle temporal gyrus, and similar to animal findings, reduced extinction learning. The current findings suggest that intranasal OT impedes fear extinction learning in humans regardless of the timepoint of administration, providing new insights and directions for future translational research and clinical applications.
The effect of intranasal oxytocin treatment on conditioned fear extinction and recall in a healthy human sample
Rationale To improve outcomes for patients undergoing extinction-based therapies (e.g., exposure therapy) for anxiety disorders such as post-traumatic stress disorder (PTSD), there has been interest in identifying pharmaceutical compounds that might facilitate fear extinction learning and recall. Oxytocin (OT) is a mammalian neuropeptide that modulates activation of fear extinction-based neural circuits and fear responses. Little is known, however, about the effects of OT treatment on conditioned fear responding and extinction in humans. Objectives The purpose of the present study was to assess the effects of OT in a fear-potentiated startle task of fear conditioning and extinction. Methods A double-blind, placebo-controlled study of 44 healthy human participants was conducted. Participants underwent a conditioned fear acquisition procedure, after which they were randomized to treatment group and delivered OT (24 IU) or placebo via intranasal (IN) spray. Forty-five minutes after treatment, participants underwent extinction training. Twenty-four hours later, subjects were tested for extinction recall. Results Relative to placebo, the OT group showed increased fear-potentiated startle responding during the earliest stage of extinction training relative to placebo; however, all treatment groups showed the same level of reduced responding by the end of extinction training. Twenty-four hours later, the OT group showed significantly higher recall of extinction relative to placebo. Conclusions The current study provides preliminary evidence that OT may facilitate fear extinction recall in humans. These results support further study of OT as a potential adjunctive treatment for extinction-based therapies in fear-related disorders.
Re-encountering the phobic cue within days after a reconsolidation intervention is crucial to observe a lasting fear reduction in spider phobia
Memory reconsolidation interventions offer an exciting alternative to exposure treatment because they may target fear memories directly, thereby preventing relapse. A previous reconsolidation intervention for spider fear abruptly reduced avoidance behaviour, whereas changes in self-reported fear followed later. In this pre-registered placebo-controlled study, we first aimed to conceptually replicate these effects in spider phobia. Second, we investigated whether re-encountering the phobic cue after the reconsolidation intervention is necessary for changes in self-reported fear to occur. Third, we tested whether the window to trigger such changes is time limited. Individuals with spider phobia ( N  = 69) were randomized into three groups and underwent a memory reactivation procedure with a tarantula, followed immediately by propranolol (reconsolidation intervention) or placebo. One reconsolidation intervention group and the placebo group re-encountered spiders two days after treatment in behavioural approach tasks, whereas another reconsolidation intervention group re-encountered spiders after four weeks. Changes in spider avoidance behaviour and self-reported fear were followed for one year. In the short term, the reconsolidation intervention was not more effective than placebo: both conditions benefited from the intervention. In the long term, the reconsolidation intervention was more effective than placebo, but only when the phobic stimulus was re-encountered within days after treatment. Specifically, we found less tarantula avoidance behaviour and self-reported fear over the course of one year when spiders were re-encountered two days after the reconsolidation intervention, but not when the behavioural test was conducted four weeks after the intervention. These findings challenge the idea that a reconsolidation-inspired intervention alone is sufficient to treat clinical fears: Experiencing the behavioural change during the re-encounter within days after the reconsolidation window has closed seems crucial to observe a lasting fear reduction.