OPEN Foundation

A. Gamma

Psychometric Evaluation of the Altered States of Consciousness Rating Scale (OAV)

Abstract

This paper describes a refinement of Dittrich’s Altered States of Consciousness questionnaire. This questionnaire is among the most widely used self-report questionnaires for retrospectively assessing subjective experiences induced by psychedelics and other psychoactive drugs. Using data collected over many years from 591 human volunteers, they factored the original four subscales developed by Dittrich into 11 new subscales. This new improved instrument will play an important role in more precisely defining the qualitative subjective experiences in research with psychedelics.

Background: The OAV questionnaire has been developed to integrate research on altered states of consciousness (ASC). It measures three primary and one secondary dimensions of ASC that are hypothesized to be invariant across ASC induction methods. The OAV rating scale has been in use for more than 20 years and applied internationally in a broad range of research fields, yet its factorial structure has never been tested by structural equation modeling techniques and its psychometric properties have never been examined in large samples of experimentally induced ASC.

Methodology/Principal Findings: The present study conducted a psychometric evaluation of the OAV in a sample of psilocybin (n = 327), ketamine (n = 162), and MDMA (n = 102) induced ASC that was obtained by pooling data from 43 experimental studies. The factorial structure was examined by confirmatory factor analysis, exploratory structural equation modeling, hierarchical item clustering (ICLUST), and multiple indicators multiple causes (MIMIC) modeling. The originally proposed model did not fit the data well even if zero-constraints on non-target factor loadings and residual correlations were relaxed. Furthermore, ICLUST suggested that the ‘‘oceanic boundlessness’’ and ‘‘visionary restructuralization’’ factors could be combined on a high level of the construct hierarchy. However, because these factors were multidimensional, we extracted and examined 11 new lower order factors. MIMIC modeling indicated that these factors were highly measurement invariant across drugs, settings, questionnaire versions, and sexes. The new factors were also demonstrated to have improved homogeneities, satisfactory reliabilities, discriminant and convergent validities, and to differentiate well among the three drug groups.

Conclusions/Significance: The original scales of the OAV were shown to be multidimensional constructs. Eleven new lower order scales were constructed and demonstrated to have desirable psychometric properties. The new lower order scales are most likely better suited to assess drug induced ASC.

Studerus, E., Gamma, A., & Vollenweider, F. X. (2010). Psychometric Evaluation of the Altered States of Consciousness Rating Scale (OAV). PLoS ONE, 5(8). http://dx.doi.org/10.1371/journal.pone.0012412
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No Difference in Brain Activation During Cognitive Performance Between Ecstasy (3,4-Methylenedioxymethamphetamine) Users and Control Subjects: A [H215O]-Positron Emission Tomography Study

Abstract

The long-term use of the serotonin-releaser and uptake-inhibitor 3,4-methylenedioxymethamphetamine (MDMA, “Ecstasy”) has been associated with memory impairments and increased liability to depressive mood and anxiety attacks. It is unclear, however, whether these psychologic deviations are reflected in alterations of the underlying neurophysiologic substrate. The authors compared mood and regional cerebral blood flow (rCBF) profiles between regular polytoxic Ecstasy users and Ecstasy-naive controls. Brain activity as indexed by rCBF was measured during cognitive activation by an attentional task using positron emission tomography and [fusion_builder_container hundred_percent=”yes” overflow=”visible”][fusion_builder_row][fusion_builder_column type=”1_1″ background_position=”left top” background_color=”” border_size=”” border_color=”” border_style=”solid” spacing=”yes” background_image=”” background_repeat=”no-repeat” padding=”” margin_top=”0px” margin_bottom=”0px” class=”” id=”” animation_type=”” animation_speed=”0.3″ animation_direction=”left” hide_on_mobile=”no” center_content=”no” min_height=”none”][H2(15)O]. Mood was assessed by means of the Hamilton Rating Scale for Depression (HAM-D) and the EWL Mood Rating Scale. Statistical parametric mapping revealed that brain activity did not differ between the two groups. Both groups also performed equally on the cognitive task requiring sustained attention. However, significantly higher levels of depressiveness as determined by the HAM-D and EWL scales were found in Ecstasy-using subjects. These data indicate that, despite differences in mood, polytoxic Ecstasy users do not differ from Ecstasy-naive controls in terms of local brain activity. Heightened depressiveness in the Ecstasy group was consistent with results from previous studies and could be related to serotonergic hypofunction resulting from repeated MDMA consumption. However, this study cannot exclude the possibility that the observed differences are preexisting rather than a result of Ecstasy use.

 

Gamma, A., Buck, A., Berthold, T., & Vollenweider, F. X. (2001). No difference in brain activation during cognitive performance between ecstasy (3, 4-methylenedioxymethamphetamine) users and control subjects: a [H215O]-positron emission tomography study. Journal of clinical psychopharmacology, 21(1), 66-71. http://dx.doi.org/10.1097/00004714-200102000-00012

 

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