178 Depressive Disorders
can induce depressive mood di sturbances. Clinical judgment is essential to determine
whether the medication is truly associated with inducing the depressive disorder or
whether a primary depressive disorder happen ed to have its onset while the person was
receiving the treatment. For example, a depres sive episode that developed within the first
several weeks of beginning alpha-methyldopa (an antihypertensive agent) in an individ-
ual with no history of major depressive diso rder would qualify for the diagnosis of med-
ication-induced depressive diso rder. In some cases, a prev iously established condition
(e.g., major depressive disorder , recurrent) can recur while th e individual is coincidentally
taking a medication that has the capacity  to cause depressive symptoms (e.g., L-dopa, oral
contraceptives). In such cases, the clinicia n must make a judgment  as to whether the med-
ication is causative in this particular situation.
A substance/medication-induced depressive disorder is distinguished from a primary
depressive disorder by considering the onset, course, and other factors associated with the
substance use. There must be evidence from the history, phy sical examination, or labora-
tory findings of substance use, abuse, intoxication, or withdrawal prior to the onset of the
depressive disorder. The withdrawal state for some substances can be relatively pro-
tracted, and thus intense depressive symptoms can last for a long period after the cessation
of substance use. 
Prevalence
In a nationally representative U.S. adult po pulation, the lifetime pr evalence of substance/
medication-induced depressive disorder is 0.26%.
Development and Course
A depressive disorder associated with the use of substance (i.e., alcoho l, illicit drugs, or a