180 Depressive Disorders
Primary depressive disorder. A substance/medication-induc ed depressive disorder is
distinguished from a primary de pressive disorder by the fact that a substance is judged to
be etiologically related to the symptoms, as  described earlier (see section “Development
and Course” for this disorder).
Depressive disorder due to another medical condition. Because individuals with other
medical conditions often take medications for th ose conditions, the clinician must consider the
possibility that the mood symptoms are caused by the physiological consequences of the med-
ical condition rather than the medication, in which case depres sive disorder due to another
medical condition is diagnosed. The history often provides the primary basis for such a judg-
ment. At times, a change in the treatment for the other medical condition (e.g., medication sub-
stitution or discontinuation) may be needed to determine empirically whether the medication
is the causative agent. If the clinician has ascertained that the disturbance is a function of both
another medical condition and su bstance use or withdrawal, both  diagnoses (i.e., depressive
disorder due to another medical condition and substance/medication-induced depressive
disorder) may be given. When there is insuffic ient evidence to determine whether the depres-
sive symptoms are associated with substance (including a medication) ingestion or with-
drawal or with another medical condition or are primary (i.e., not a function of either a
substance or another medical condition), a diagno sis of other specified depressive disorder or
unspecified depressive diso rder would be indicated.
Comorbidity
Compared with individuals with major depre ssive disorder and no comorbid substance
use disorder, those with substance/medicati on-induced depressive disorder have higher