Abstract
Introduction The Young Mania Rating Scale (YMRS) is the gold standard to
assess manic symptoms of bipolar disorder, yet the clinical meaning of scores is
unknown. To clinically understand and interpret YMRS scores, we examined
linkages between the total and change scores of YMRS with the Clinical Global
Impression (CGI) ratings.
Methods Individual participant data (N=2,988) from eight
randomized, double-blind, placebo-controlled trials were included. Data were
collected at baseline and subsequent visits. Spearman’s correlation
coefficients ρ were computed, and equipercentile linking was
implemented.
Results A YMRS score of 6 points corresponded approximately to
‘borderline mentally ill,’ 12 points to ‘mildly
ill,’ 20 points to ‘moderately ill,’ 30 points to
‘markedly ill,’ 40 points to ‘severely ill,’ and
52 points to ‘among the most extremely ill’ patients on the
CGI-S. A reduction of CGI-S by one point as well as ‘minimally
improved’ on the CGI-I corresponded approximately to an absolute
decrease of 4 to 8 YMRS points or a 21% to 29% reduction of YMRS
baseline score whereas a reduction of CGI-S by two points and ‘much
improved’ on the CGI-I corresponded to an absolute decrease of 10 to 15
points or a 42% to 53% reduction of YMRS baseline score.
Discussion The current study findings offer clinicians meaningful cutoff
values to interpret YMRS scores. Moreover, these values contribute to the
definition of treatment targets, response, remission, and entry criteria in
mania trials.
Key words
bipolar - cutoff - response - remission criterion - interpretation - minimal clinically
important difference