However, in some rare cases ongoing psychotic symptoms and other psychological sequelae have been reported (Glass & Bowers, 1970; Smart & Bateman, 1967). Although uncommon, it has been hypothesized that such persisting negative effects of hallucinogens may be related to personal or familial predisposition to psychotic disorders (Strassman, 1984), thus underscoring the importance of careful screening in clinical research. The so-called CSTC model of information processing proposes that deficits in early information processing may underlie alterations in perception, cognition, and the sense of self seen in psychedelic-induced ASC (Vollenweider and Geyer, 2001). This model suggests that the inability to filter, inhibit, and screen out exteroceptive and interoceptive stimuli may lead to sensory overload and a breakdown of cognitive integrity, leading to hallucinations and alterations of ego functioning. Deficits in preattentive sensorimotor gating have been reported repeatedly after psilocybin and LSD administration (Vollenweider et al., 2007; Quednow et al., 2012; Schmid et al., 2015) and have been related to alterations in cognitive functioning (Vollenweider et al., 2007; Quednow et al., 2012). The CSTC model proposes that the thalamus plays a key role within CSTC feedback loops for gating external and internal information to the cortex, and therefore is crucially involved in the regulation of the level of awareness and attention (Vollenweider et al., 2007; Geyer and Vollenweider, 2008).
Bad Trips on Hallucinogenic Drugs
Along these lines, Szabo (2015) suggested a possible therapeutic role for psychedelics in modulating immune function and reducing inflammation, potentially through sigma-1 receptor mediated pathways. These claims are consistent with preclinical data showing administration of the 5-HT2AR agonist (R)-2,5-dimethoxy-4-iodoamphetamine (R-DOI) greatly suppresses tumor necrosis factor alpha (TNF-α) induced inflammation in vitro (Yu et al., 2008), and in vivo (Nau et al., 2013). Furthermore, these results have been found to generalize to a rodent model of allergic asthma, indicating considerable clinical potential (Nau et al., 2015). From its inception, research with 5-HT2AR agonist hallucinogens was marked with considerable controversy surrounding the nature of these drugs and their effects. Early researchers struggled to create a context within which to understand these unusual substances (Osmond, 1957; Ruck et al., 1979). Many were intrigued by the psychosis mimicking or psychotomimetic properties of these compounds.
Hallucinogens Effects: Long- And Short-Term
- Importantly, antagonist studies using the highly selective 5-HT2A receptor antagonist M demonstrated that the anti-inflammatory effects of R-DOI in the whole animal were mediated by activation of the 5-HT2A receptor, as they were in the earlier cell culture studies.
- Drug treatments consisted of neurotrophin-3 (NT-3) and LSD given either alone or in combination.
- Depending on the drug, overdosing on a hallucinogen can create a variety of harmful and potentially fatal symptoms.
- Furthermore, the immediate postsession mystical experience score was linearly correlated with therapeutic efficacy.
- Magic mushrooms contain psilocybin which imparts psychedelic effects to anyone who ingests them.
5-HT2A receptor immunoreactivity is also observed in every superficial nucleus of the rat amygdala. Pazos et al. (1987) examined 5-HT2 receptor distribution in the human brain using light microscopic autoradiography with the 5-HT2A antagonist ligand [3H]ketanserin. A heterogeneous distribution of 5-HT2 receptor densities was observed, with high expression localized over layers III and V of several cortical areas, including the frontal, parietal, temporal, and occipital lobes, the anterogenual cortex, and the entorhinal area.