OPEN Foundation

Psychology

Natural speech algorithm applied to baseline interview data can predict which patients will respond to psilocybin for treatment-resistant depression

Abstract

BACKGROUND:
Natural speech analytics has seen some improvements over recent years, and this has opened a window for objective and quantitative diagnosis in psychiatry. Here, we used a machine learning algorithm applied to natural speech to ask whether language properties measured before psilocybin for treatment-resistant can predict for which patients it will be effective and for which it will not.
METHODS:
A baseline autobiographical memory interview was conducted and transcribed. Patients with treatment-resistant depression received 2 doses of psilocybin, 10 mg and 25 mg, 7 days apart. Psychological support was provided before, during and after all dosing sessions. Quantitative speech measures were applied to the interview data from 17 patients and 18 untreated age-matched healthy control subjects. A machine learning algorithm was used to classify between controls and patients and predict treatment response.
RESULTS:
Speech analytics and machine learning successfully differentiated depressed patients from healthy controls and identified treatment responders from non-responders with a significant level of 85% of accuracy (75% precision).
CONCLUSIONS:
Automatic natural language analysis was used to predict effective response to treatment with psilocybin, suggesting that these tools offer a highly cost-effective facility for screening individuals for treatment suitability and sensitivity.
LIMITATIONS:
The sample size was small and replication is required to strengthen inferences on these results.
Carrillo, F., Sigman, M., Slezak, D. F., Ashton, P., Fitzgerald, L., Stroud, J., … & Carhart-Harris, R. L. (2018). Natural speech algorithm applied to baseline interview data can predict which patients will respond to psilocybin for treatment-resistant depression. Journal of affective disorders230, 84-86. 10.1016/j.jad.2018.01.006
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Ceremonial ‘Plant Medicine’ use and its relationship to recreational drug use: an exploratory study

Background: The ceremonial use of psychoactive/hallucinogenic plant based drugs, such as ayahuasca, psilocybin and others, is a growing trend in the United States (US) and globally. To date, there has been little research documenting how many people are using psychoactive substances in this context, who the users are, what benefits/risks exist in the use of these drugs and the relationship between ceremonial drug use and recreational drug use.
In this paper we describe a cohort of plant medicine facilitators in the US and explore how they differentiate plant medicine use from recreational drug use.
Methods: Using modified ethnography, individual interviews were conducted in 2016 with 15 participants who are currently facilitating plant medicine ceremonies in the US. Descriptive content analysis was performed to discover themes and to inform a larger mixed-method study.
Results: Ceremonial drug use was seen by participants as a natural healing and treatment modality used in the context of community and ritual. Three main themes were identified relating to participants’ differentiation between ceremonial plant medicine use and recreational drug use: (1) participants see a clear delineation between plant medicine use and recreational drug use; (2) plant medicine is seen as a potential treatment for addiction, but concerns exist regarding potential interference with recovery; and (3) plant medicine use may influence recreational use.
Conclusions: More research is needed on who is using plant medicine, motivators for use, perceived and real risks and benefits of plant medicine use and harm reduction techniques regarding safe ingestion.
Dorsen, C., Palamar, J., & Shedlin, M. G. (2018). Ceremonial ‘Plant Medicine’use and its relationship to recreational drug use: an exploratory study. Addiction Research & Theory, 1-8. 10.1080/16066359.2018.1455187
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Ketamine for the treatment of major depressive disorder and bipolar depression: A review of the literature

Abstract

INTRODUCTION:
Over the past decade, ketamine has been studied for major depressive disorder and bipolar depression. Ketamine is believed to exert its antidepressant properties through N-methyl-D-aspartate receptor antagonism.
METHODS:
Study authors completed a literature review of seven randomized controlled trials of ketamine usage in major depressive disorder and bipolar depression.
RESULTS:
Ketamine demonstrated a statistically significant improvement over placebo or midazolam in major depressive disorder. Ketamine also exhibited a statistically significant improvement over placebo in bipolar depression.
DISCUSSION:
Ketamine has shown promise in quickly reducing symptoms in patients with treatment resistant depression and bipolar depression. Using ketamine may be helpful for patients that have exhausted other therapeutic options.
Grady, S. E., Marsh, T. A., Tenhouse, A., & Klein, K. (2017). Ketamine for the treatment of major depressive disorder and bipolar depression: A review of the literature. Mental Health Clinician7(1), 16-23. 10.9740/mhc.2017.01.016
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Four weekly ayahuasca sessions lead to increases in “acceptance” capacities: a comparison study with a standard 8-week mindfulness training program

Abstract

Background: The therapeutic effects of the Amazonian plant tea ayahuasca may relate to its ability to enhance mindfulness capacities. Ayahuasca induces a modified state of awareness through the combined action of its active principles: the psychedelic N,N-dimethyltryptamine (DMT) and a series of centrally acting β-carbolines, mainly harmine and tetrahydroharmine. To better understand the therapeutic potential of ayahuasca, here we compared the impact on mindfulness capacities induced by two independent interventions: (a) participation in four ayahuasca sessions without any specific purpose related to improving mindfulness capacities; and (b) participation in a standard mindfulness training course: 8 weeks mindfulness-based stress reduction (MBSR), with the specific goal of improving these skills.

Methods: Participants of two independent groups completed two self-report instruments: The Five Facet Mindfulness Questionnaire (FFMQ) and the Experiences Questionnaire (EQ). The MINDSENS Composite Index was also calculated, including those EQ and FFMQ items that have proven to be the most sensitive to meditation practice. Group A (n = 10) was assessed before and after the last of four closely spaced consecutive ayahuasca sessions. Group B (n = 10) was assessed before and after completion of a standard 8-week MBSR course.

Results: MBSR training led to greater increases in overall mindfulness scores after the 8-week period. MBSR but not ayahuasca led to increases in the MINDSENS Composite Index. However, the ayahuasca sessions induced comparable increases in the Non-Judging subscale of the FFMQ, specifically measuring “acceptance.” Improving this capacity allows for a more detached and less judgmental stance toward potentially distressing thoughts and emotions.

Conclusion: The present findings suggest that a small number of ayahuasca sessions can be as effective at improving acceptance as more lengthy and costly interventions. Future studies should address the benefits of combining ayahuasca administration with mindfulness-based interventions. This will allow us to investigate if ayahuasca will improve the outcome of psychotherapeutic interventions.

Soler, J., Elices, M., Dominguez-Clave, E., Pascual, J. C., Feilding, A., Navarro-Gil, M., … & Riba, J. (2018). Four weekly ayahuasca sessions lead to increases in “acceptance” capacities: a comparison study with a standard 8-week mindfulness training program. Frontiers in Pharmacology9, 224. 10.3389/fphar.2018.00224
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Role of the 5-HT2A receptor in self- and other-initiated social interaction in LSD-induced states – a pharmacological fMRI study

Abstract

Distortions of self-experience are critical symptoms of psychiatric disorders and have detrimental effects on social interactions. In light of the immense need for improved and targeted interventions for social impairments, it is important to better understand the neurochemical substrates of social interaction abilities. We therefore investigated the pharmacological and neural correlates of self- and other-initiated social interaction. In a double-blind, randomized, counterbalanced, cross-over study 24 healthy human participants (18 males and 6 females) received either 1) placebo+placebo 2) placebo+lysergic acid diethylamide (LSD) (100 μg p.o.), or 3) ketanserin (40 mg p.o.)+LSD (100 μg p.o.) at three different occasions. Participants took part in an interactive task using eye-tracking and functional magnetic resonance imaging completing trials of self- and other-initiated joint and non-joint attention. Results demonstrate first, that LSD reduced activity in brain areas important for self-processing, but also social cognition, second that change in brain activity was linked to subjective experience, and third that LSD decreased the efficiency of establishing joint attention. Furthermore, LSD-induced effects were blocked by the serotonin 2A receptor (5-HT2AR) antagonist ketanserin, indicating that effects of LSD are attributable to 5-HT2AR stimulation. The current results demonstrate that activity in areas of the ‘social brain’ can be modulated via the 5-HT2AR thereby pointing towards this system as a potential target for the treatment of social impairments associated with psychiatric disorders.SIGNIFICANCE STATEMENTDistortions of self-representation and, potentially related to this, dysfunctional social cognition are central hallmarks of various psychiatric disorders and critically impact disease development, progression, treatment, as well as real-world functioning. However, these deficits are insufficiently targeted by current treatment approaches. The administration of lysergic acid diethylamide (LSD) in combination with functional magnetic resonance imaging and real-time eye-tracking offers the unique opportunity to study alterations in self-experience, their relation to social cognition, and the underlying neuropharmacology. Results demonstrate that LSD alters self-experience as well as basic social cognition processing in areas of the ‘social brain’. Furthermore, these alterations are attributable to 5-HT2A receptor stimulation, thereby pinpointing towards this receptor system in the development of pharmacotherapies for sociocognitive deficits in psychiatric disorders.
Preller, K. H., Schilbach, L., Pokorny, T., Flemming, J., Seifritz, E., & Vollenweider, F. X. (2018). Role of the 5-HT2A receptor in self-and other-initiated social interaction in LSD-induced states—a pharmacological fMRI study. Journal of Neuroscience, 1939-17. 10.1523/JNEUROSCI.1939-17.2018
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Hallucinogen Persisting Perception Disorder: Etiology, Clinical Features, and Therapeutic Perspectives

Abstract

Hallucinogen Persisting Perception Disorder (HPPD) is a rare, and therefore, poorly understood condition linked to hallucinogenic drugs consumption. The prevalence of this disorder is low; the condition is more often diagnosed in individuals with a history of previous psychological issues or substance misuse, but it can arise in anyone, even after a single exposure to triggering drugs. The aims of the present study are to review all the original studies about HPPD in order to evaluate the following: (1) the possible suggested etiologies; (2) the possible hallucinogens involved in HPPD induction; (3) the clinical features of both HPPD I and II; (4) the possible psychiatric comorbidities; and (5) the available and potential therapeutic strategies. We searched PubMed to identify original studies about psychedelics and Hallucinogen Persisting Perception Disorder (HPPD). Our research yielded a total of 45 papers, which have been analyzed and tabled to provide readers with the most updated and comprehensive literature review about the clinical features and treatment options for HPPD.
Martinotti, G., Santacroce, R., Pettorruso, M., Montemitro, C., Spano, M. C., Lorusso, M., … & Lerner, A. G. (2018). Hallucinogen Persisting Perception Disorder: Etiology, Clinical Features, and Therapeutic Perspectives. Brain sciences8(3), 47. 10.3390/brainsci8030047
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Repeated intranasal ketamine for treatment-resistant depression – the way to go? Results from a pilot randomised controlled trial

Abstract

BACKGROUND:
Ketamine research in depression has mostly used intravenous, weight-based approaches, which are difficult to translate clinically. Intranasal (IN) ketamine is a promising alternative but no controlled data has been published on the feasibility, safety and potential efficacy of repeated IN ketamine treatments.
METHODS:
This randomised, double-blind, placebo-controlled pilot study compared a 4-week course of eight treatments of 100 mg ketamine or 4.5 mg midazolam. Each treatment was given as 10 separate IN sprays, self-administered 5 min apart. The study was stopped early due to poor tolerability after five treatment-resistant depressed participants were included. Feasibility, safety (acute and cumulative), cognitive and efficacy outcomes were assessed. Plasma ketamine and norketamine concentrations were assayed after the first treatment.
RESULTS:
Significant acute cardiovascular, psychotomimetic and neurological side effects occurred at doses < 100 mg ketamine. No participants were able to self-administer all 10 ketamine sprays due to incoordination; treatment time occasionally had to be extended (>45 min) due to acute side effects. No hepatic, cognitive or urinary changes were observed after the treatment course in either group. There was an approximately two-fold variation in ketamine and norketamine plasma concentrations between ketamine participants. At course end, one participant had remitted in each of the ketamine and midazolam groups.
CONCLUSIONS:
IN ketamine, with the drug formulation and delivery device used, was not a useful treatment approach in this study. Absorption was variable between individuals and acute tolerability was poor, requiring prolonged treatment administration time in some individuals. The drug formulation, the delivery device, the insufflation technique and individual patient factors play an important role in tolerability and efficacy when using IN ketamine for TRD.
Gálvez, V., Li, A., Huggins, C., Glue, P., Martin, D., Somogyi, A. A., … & Loo, C. K. (2018). Repeated intranasal ketamine for treatment-resistant depression–the way to go? Results from a pilot randomised controlled trial. Journal of Psychopharmacology32(4), 397-407. 10.1177/0269881118760660
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Serotonergic Psychedelics: Experimental Approaches for Assessing Mechanisms of Action

Abstract

Recent, well-controlled – albeit small-scale – clinical trials show that serotonergic psychedelics, including psilocybin and lysergic acid diethylamide, possess great promise for treating psychiatric disorders, including treatment-resistant depression. Additionally, fresh results from a deluge of clinical neuroimaging studies are unveiling the dynamic effects of serotonergic psychedelics on functional activity within, and connectivity across, discrete neural systems. These observations have led to testable hypotheses regarding neural processing mechanisms that contribute to psychedelic effects and therapeutic benefits. Despite these advances and a plethora of preclinical and clinical observations supporting a central role for brain serotonin 5-HT2A receptors in producing serotonergic psychedelic effects, lingering and new questions about mechanisms abound. These chiefly pertain to molecular neuropharmacology. This chapter is devoted to illuminating and discussing such questions in the context of preclinical experimental approaches for studying mechanisms of action of serotonergic psychedelics, classic and new.

Canal, C. E. (2018). Serotonergic Psychedelics: Experimental Approaches for Assessing Mechanisms of Action. 10.1007/164_2018_107
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The entropic brain – Revisited

Abstract

The entropic brain hypothesis proposes that within upper and lower limits, after which consciousness may be lost, the entropy of spontaneous brain activity indexes the informational richness of conscious states. Here the hypothesis is revisited four years on from its original publication. It is shown that the principle that the entropy of brain activity is elevated in the psychedelic state is increasingly well supported by separate and independent studies and analyses, and evidence for greater brain criticality under psychedelics is also highlighted. It is argued that heightened brain criticality enables the brain to be more sensitive to intrinsic and extrinsic perturbations which may translate as a heightened susceptibility to “set” and “setting”. This updated version of the original entropic brain hypothesis now offers more concrete information on specific measures of brain entropy and suggests new studies to scrutinise it further, as well as examine its utility for describing and informing the treatment of psychiatric and neurological conditions such as depression and disorders of consciousness.
Carhart-Harris, R. L. (2018). The entropic brain-Revisited. Neuropharmacology. 10.1016/j.neuropharm.2018.03.010
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Psilocin and ketamine microdosing: effects of subchronic intermittent microdoses in the elevated plus-maze in male Wistar rats

Abstract

Short-term moderate doses of serotonergic and dissociative hallucinogens can be useful in the treatment of anxiety. Recently, a trend has developed for long-term intermittent ‘microdosing’ (usually one-tenth of a ‘full’ active dose), with reports of long-lasting relief from anxiety and related disorders; however, there is no scientific evidence for the efficacy of therapeutic microdosing nor to show its lasting effects. The objective of this study was to test for lasting effects on anxiety in rats after microdosing with ketamine or psilocin. Over 6 days, Wistar rats (N=40) were administered ketamine (0.5 or 3 mg/kg), psilocin (0.05 or 0.075 mg/kg), or saline on three occasions. A 5-min elevated plus-maze test was conducted 48 h after the final drug treatment (n=8). Dependent variables were entries (frequency), spent time (%), and distance traveled (cm) in each zone, as well as total frequency of rears, stretch-attend postures, and head dips. Statistical analyses of drug effects used separate independent one-way analysis of variance and pair-wise comparisons using independent t-tests. Statistical effects were modest or borderline and were most consistent with a mildly anxiogenic profile, which was significant at lower doses; however, this conclusion remains tentative. The lower doses of ketamine and psilocin produced comparable effects (to one another) across each variable, as did the higher doses. This pattern of effects may suggest a common (e.g. neurotransmitter/receptor) mechanism. We conclude that microdosing with hallucinogens for therapeutic purposes might be counter-productive; however, more research is needed to confirm our findings and to establish their translational relevance to clinical ‘psychedelic’ therapy.
Horsley, R. R., Páleníček, T., Kolin, J., & Valeš, K. (2018). Psilocin and ketamine microdosing: effects of subchronic intermittent microdoses in the elevated plus-maze in male Wistar rats. Behavioural pharmacology. 10.1097/FBP.0000000000000394
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