Psychometric evaluation of the altered states of consciousness rating scale (OAV).
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.


RESULTS
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
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
Erich
E
Neuropsychopharmacology and Brain Imaging and Heffter Research Center, University Hospital of Psychiatry Zurich, Zurich, Switzerland. erich.studerus@bli.uzh.ch
Gamma
Alex
A
Vollenweider
Franz X
FX
D000328:Adult; D016000:Cluster Analysis; D003243:Consciousness / Q000187:drug effects; D005260:Female; D006801:Humans; D007649:Ketamine / Q000494:pharmacology; D008297:Male; D008962:Models, Theoretical; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000494:pharmacology; D011562:Psilocybin / Q000494:pharmacology; D011594:Psychometrics / Q000379:methods*; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires
D011562:Psilocybin; D007649:Ketamine; D018817:N-Methyl-3,4-methylenedioxyamphetamine
J Psychopharmacol. 2008 Aug;22(6):603-20
18593734
Br J Math Stat Psychol. 2001 Nov;54(Pt 2):315-23
11817096
J Psychopathol Behav Assess. 2009;31(4):320-330
20442793
Psychopharmacology (Berl). 2001 Mar 1;154(2):161-8
11314678
Eur Psychiatry. 1998 Dec;13(8):399-406
19698655
Multivariate Behav Res. 1979 Jan 1;14(1):57-74
26766619
Brain Res Bull. 2001 Nov 15;56(5):495-507
11750795
Neuropsychopharmacology. 1999 May;20(5):424-33
10192823
Schizophr Res. 2005 Jan 1;72(2-3):235-48
15560968
Scand J Psychol. 2007 Dec;48(6):459-66
18028068
Behav Med. 1998 Fall;24(3):107-14
9850804
Int J Geriatr Psychiatry. 2001 Oct;16(10):980-6
11607943
J Pers Soc Psychol. 1992 Nov;63(5):832-8
1447695
Psychopharmacology (Berl). 2006 Aug;187(3):268-83; discussion 284-92
16826400
Trends Pharmacol Sci. 2008 Sep;29(9):445-53
19086254
Psychol Assess. 2000 Sep;12(3):287-97
11021152
J Gerontol B Psychol Sci Soc Sci. 2002 Sep;57(5):S275-84
12198107
Biol Psychiatry. 2002 Mar 1;51(5):400-6
11904134
J Pers Assess. 2008 May;90(3):280-5
18444124
Eur Neuropsychopharmacol. 2000 Jul;10(4):289-95
10871712
Psychol Assess. 2007 Dec;19(4):369-81
18085930
Psychometrika. 1965 Jun;30:179-85
14306381
Multivariate Behav Res. 1979 Oct 1;14(4):403-14
26804437
Arch Gen Psychiatry. 1994 Feb;51(2):98-108
8297217
PLoS One. 2009 Jun 01;4(6):e5754
19484132
J Pers Assess. 2000 Feb;74(1):48-62
10779932
Psychopharmacology (Berl). 2004 Mar;172(2):145-56
14615876
Psychol Bull. 1999 Jan;125(1):3-30
9990843
J Psychopharmacol. 2009 Nov;23(8):923-35
18635693
Multivariate Behav Res. 2009 Jan-Feb;44(1):1-27
26795105
Pharmacopsychiatry. 1998 Jul;31 Suppl 2:80-4
9754838
Multivariate Behav Res. 1966 Apr 1;1(2):245-76
26828106
Psychometrika. 2010 Jun;75(2):243-248
20640194
J Appl Psychol. 2004 Oct;89(5):792-808
15506861
Psychol Assess. 2010 Sep;22(3):471-91
20822261
Pharmacopsychiatry. 2005 Nov;38(6):301-11
16342002