Objective: It has been argued that Axis I and Axis II disorders diagnosed i
n substance users refer to substance-induced conditions rather than to inde
pendent psychiatric conditions; this argument will be referred to as the su
bstance-related artifact hypothesis. Furthermore, Axis II symptoms co-occur
ring with Axis I disorders have been attributed to the contamination of per
sonality assessment by mood and/or anxiety state effects (the trait-state a
rtifact hypothesis). The present study is the first to prospectively examin
e thr validity of these two hypothesized "artifacts" in substance users. Me
thod: In 276 individuals (57.6% female) applying for substance use treatmen
t, current substance use disorders, mood/anxiety disorders and Axis II diso
rders were diagnosed using semistructured interviews both at baseline and a
t I-year follow-up. The substance-related artifact hypothesis is tested by
examining the covariation between recovery from substance use disorders on
the one hand and recovery from and/or improvement of mood/anxiety and Axis
II disorders on the other hand. The trait-state artifact hypothesis is test
ed by examining the covariation between recovery from mood/anxiety disorder
s on the one hand and recovery from and/or improvement of Axis II disorders
on the other hand. Results: Recovery from substance use disorders covaried
with recovery from and improvement of mood/anxiety disorders, bur not with
recovery from or improvement of Axis II pathology. Furthermore, recovery f
rom mood/anxiety disorders covaried with recovery from and improvement of p
ersonality disorders, in particular Cluster C disorders. Conclusions: Resul
ts from this study suggest-that mood/anxiety disorders, but not personality
disorders, diagnosed among people with substance use disorder may partly r
eflect substance-related artifacts. Furthermore, this study provides eviden
ce for the contention that semistructured interview assessment of Axis LI,
at least without inquiry on an item-by-item basis, is susceptible to contam
ination by mood/anxiety slate effects.