with prominent irritable mood may be difficu lt to distinguish from manic episodes with
irritable mood or from mixed episodes. This di stinction requires a careful clinical evalua-
tion of the presence of manic symptoms.
Mood disorder due to another medical condition. A major depressive episode is the
appropriate diagnosis if the mood  disturbance is not judged, based on individual history,
physical examination, and laboratory findings, to be the direct pathophysiological conse-
quence of a specific medical condition (e.g.,  multiple sclerosis, st roke, hypothyroidism).
Substance/medication-induced de pressive or bipolar disorder. This disorder is distin-
guished from major depressive disorder by the fact that a substance (e.g., a drug of abuse,
a medication, a toxin) appears to be etiologically related to the mood disturbance. For ex-
ample, depressed mood that occurs only in the context of withdrawal from cocaine would
be diagnosed as cocaine-induced depressive disorder. 
Attention-deficit/hyperactivity disorder. Distractibility and low frustration tolerance
can occur in both attention-deficit/ hypera ctivity disorder and a major depressive epi-
sode; if the criteria are met for both, attention-deficit/hyperactivity disorder may be diag-
nosed in addition to the mood  disorder. However, the clinic ian must be cautious not to
overdiagnose a major depressive episode in ch ildren with attention-deficit/hyperactivity
disorder whose disturbance in mood is characte rized by irritability rather than by sadness
or loss of interest.