The self-medication hypothesis suggests that clients use substances as a me
ans to reduce their psychiatric symptoms. However, substance use as a form
of self-medication also can be interpreted as exacerbating symptoms. Behavi
oral Principles may provide a useful perspective to understand this apparen
t contradiction. The authors investigated the relationship of types of subs
tance use with psychiatric symptoms among 220 participants with co-occurrin
g disorders in an acute care psychiatric unit. Participants were assessed f
or their use of 6 different classes of substances within 3 months of admiss
ion. Hierarchical logistic regression analyses found that particular substa
nces were associated with each of the diagnostic categories and that the Pa
ttern of associated substances differed by diagnostic category in a way tha
t supported both self-medication and symptom exacerbation hypotheses. Self-
medication and symptom exacerbation can be defined and treated in cognitive
-behavioral terms. Harm reduction strategies seem to offer great promise in
this context.