The current chapter presents the literature evaluating the effects of classic psychedelic treatments on five substance use disorders: alcohol, tobacco, opioid, stimulant, and cannabis. Most work on psychedelics and substance use disorders was conducted for alcohol use disorder. A range of classic psychedelics (LSD, psilocybin, and ayahuasca) appear to be beneficial for facilitating both reduced...
Patients with a life-threatening disease (LTD) sometimes suffer from end-of-life distress (EOLD) which refers to the physical, psychological, emotional, and spiritual suffering related to chronic illness and the possibility of death. Palliative care interventions seek to improve the quality of life of patients with EOLD and their significant others. Currently, a range of psychological and...
Psychedelics are primarily recognized for their profound behavioral effects, leading most research on psychedelics and their primary target, the 5-HT2A receptor, to focus on brain activity. However, these receptors are not only found within the brain and are present in nearly every tissue and cell type throughout the body, playing a significant role alongside serotonin in modulating various...
Classic psychedelics have been used by various cultures for millennia for healing and religious purposes. The modern era of psychedelic science began with the first empirical experiments by Dr. Arthur Heffter in 1898 to determine just what they are when he discovered the active alkaloid in the peyote cactus responsible for its intoxicating effects and named it mescaline. As with many aspects of...
In recent years, public and academic interest into psychedelics has increased, given the clinical evidence of their potential benefits for treating psychiatric conditions such as major depressive disorder (MDD). While this has been accompanied by several landmark human studies, mechanistic studies in rodents are still relatively few, but such studies are crucial for understanding the...
Molecular brain imaging by positron emission tomography (PET) and single photon emission computer-tomography (SPECT) entails the mapping of the cerebral distribution of radiopharmaceuticals that track physiological processes such as blood perfusion and glucose metabolism, or the abundance in brain of specific molecular targets such as neuroreceptors. PET and SPECT emerged as useful in vivo...
This paper explores the therapeutic potential of DMT in neuroprotective strategies, particularly concerning ischemia-reperfusion injury (IRI) and neurodegenerative disorders. Besides its potent serotonin receptor actions, DMT is also an endogenous agonist of the sigma-1 receptor (Sig-1R). Sigma receptors are a unique family of proteins with high expression in the brain and spinal cord and have...
Post-Traumatic Stress Disorder (PTSD) is a severe psychiatric condition that develops after exposure to trauma such as combat, natural disasters, or assault. It is characterized by re-experiencing trauma, avoidance, hyperarousal, and negative alterations in cognition and mood. Since its formal inclusion in the Diagnostic and Statistical Manual of Mental Disorders (DSM)-III in 1980, PTSD has...
To design therapeutic trials and select the most appropriate substance and dose for an indication, a detailed understanding of clinical pharmacology is crucial. In recent years, several studies have explored the human pharmacology of different psychedelics and 3,4-methylendioxymethylamphetamin (MDMA). This chapter summarizes pharmacological characteristics of the serotonergic psychedelics...
This chapter reviews the effects of classic psychedelics on human oscillatory brain activity, as measured by resting-state electroencephalography (EEG) and magnetoencephalography (MEG). Across moderate to high doses of LSD, psilocybin, ayahuasca, and DMT, a consistent reduction in alpha power (8-13 Hz) emerges, particularly in occipital regions. Below 30 Hz, desynchronization is typical,...
Depressive disorders continue to pose a major clinical challenge worldwide, particularly given the high prevalence and increasing number of treatment-resistant cases. Over the past decade, advances in research have elucidated the antidepressant potential of psilocybin and other 5-HT₂A receptor agonists in patients with major depressive disorder (MDD) and treatment-resistant depression (TRD)....
Human neuroimaging with functional Magnetic Resonance Imaging has been a key feature of the current wave of psychedelic research, in both healthy and clinical populations. The available data has suggested that classic psychedelics (psilocybin, LSD, DMT) have a characteristic effect of acutely and profoundly disrupting the normal pattern of resting-state connectivity in the human brain, and that...
Clinical trials using full doses of psychedelics have provided preliminary evidence supporting their safety and efficacy in treating a variety of physical and psychological conditions. Anecdotal reports indicate that even very small amounts of these substances may provide therapeutic benefits, though robust clinical studies are still needed. This chapter reviews the current experimental studies...
Neutral hypnosis offers a valuable state for researchers interested in the nature of consciousness. By minimizing external influences and suggestions, it allows for the investigation of the intrinsic qualities of hypnotic consciousness and its relationship to normal waking states. Studies have shown that neutral hypnosis can result in a significant shift in self-perception. Self-consciousness...
For decades, psychedelics have been investigated for the treatment of psychiatric disorders. Specifically, evidence suggests that psychedelics may have therapeutic potential for the treatment of alcohol use disorder. Several studies with classic psychedelics, including LSD and psilocybin, show promising results, with psychedelics decreasing alcohol drinking and promoting abstinence in...
Adolescence is a crucial developmental period where neural circuits are refined and the brain is especially vulnerable to external insults. The endocannabinoid (eCB) system undergoes changes during adolescence which affect the way in which it modulates the development of other systems, in particular dopamine circuits, which show protracted development into adolescence. Given the rise of...
Despite reports of apparent benefits, social and political pressure beginning in the late 1960s effectively banned scientific inquiry into psychedelic substances. Covert examination of psychedelics persisted through the 1990s; the turn of the century and especially the past 10 years, however, has seen a resurgent interest in psychedelic substances (eg, LSD, ayahuasca, psilocybin). This chapter...
Marijuana, behind only tobacco and alcohol, is the most popular recreational drug in America with prevalence rates of use rising over the past decade. A wide range of research has highlighted neurocognitive deficits associated with marijuana use, particularly when initiated during childhood or adolescence. Neuroimaging, describing alterations to brain structure and function, has begun to...
Eating, drinking, sexual activity, and parenting invoke pleasure, an emotion that promotes repetition of these behaviors, are essential for survival. Euphoria, a feeling or state of intense excitement and happiness, is an amplification of pleasure, aspired to one's essential biological needs that are satisfied. People use party drugs as a shortcut to euphoria. Ecstasy...
This chapter argues that dreaming is an important state of consciousness and that it has many features that complement consciousness in the wake state. The chapter discusses consciousness in dreams and how it comes about. It discusses the changes that occur in the neuromodulatory environment and in the neuronal connectivity of the brain as we fall asleep and begin our night journeys. Dreams...
We review the literature on the neurobiology of rapid eye movement (REM) and non-rapid eye movement (NREM) sleep states and associated dreams. REM is associated with enhanced activation of limbic and amygdalar networks and decreased activation in dorsal prefrontal regions while stage II NREM is associated with greater cortical activation than REM. Not surprisingly, these disparate brain...
Individuals differ greatly in their dream recall frequency, in their incidence of recalling types of dreams, such as nightmares, and in the content of their dreams. This chapter reviews work on the waking life correlates of these differences between people in their experience of dreaming and reviews some of the neurobiological correlates of these individual differences. The chapter concludes...
(+/-)-3,4-Methylenedioxymethamphetamine (MDMA) is a commonly abused illicit drug which affects multiple organ systems. In animals, high-dose administration of MDMA produces deficits in serotonin (5-HT) neurons (e.g., depletion of forebrain 5-HT) that have been viewed as neurotoxicity. Recent data implicate MDMA in the development of valvular heart disease (VHD). The present paper reviews...
Schizophrenia is a serious mental disorder that affects up to 1% of the population worldwide. As of yet, neurochemical mechanisms underlying schizophrenia remain unknown. To date, the most widely considered neurochemical hypothesis of schizophrenia is the dopamine hypothesis, which postulates that symptoms of schizophrenia may result from excess dopaminergic neurotransmission particularly in...