When depression and substance abuse occur together, as
is common, either condition can hamper effective treatment
of the other. Behavioral interventions that address
both conditions have not been rigorously tested. Although
delivering such interventions by computer holds promise
for extending their reach, their effectiveness in treating
these co-occurring disorders remains unknown. In a randomized
trial, researchers measured the effectiveness of an
intervention combining principles of motivational interviewing
(MI) and cognitive behavioral therapy (CBT) in the
treatment of depression and co-morbid alcohol and/or cannabis
use. After a single baseline brief-intervention session,
97 persons with co-occurring depression and heavy alcohol
and/or cannabis use were randomized to receive either no
further treatment (n=30) or nine 1-hour sessions of MI/
CBT treatment delivered either by a therapist (n=35) or by
computer (n=32). Sixty-seven patients completed the
study. Depression and alcohol/cannabis use were assessed
at 3, 6, and 12 months following treatment completion.
• Although the initial treatment session demonstrated
modest efficacy for depression as well as alcohol and/
or cannabis use, outcomes across all 3 conditions were
further improved among MI/CBT recipients.
• The proportion of participants with improved depressive symptoms (Beck Depression Inventory score,
<17) and with diminished alcohol and/or cannabis use
(<50% as many hazardous use days per month) at 12
months did not differ significantly among recipients of
therapist- or computer-delivered interventions.
Comments: These data provide clear evidence that combining
interventions to target depression as well as alcohol
and/or cannabis use can improve outcomes in both conditions,
and that delivering such interventions by computer
may be effective and reduce costs associated with therapist
time. The results might have been less favorable had intent-to-
treat analyses assumed that participants lost to follow-up
had resumed drug use. In addition, the intensity of the
intervention (10 hour-long sessions) raises questions about
feasibility in typical practice settings. As computer-delivered
interventions gain acceptance, further studies to define
cost- effectiveness and completion rates outside of research
settings are warranted.

Source: . Addiction. 2009; 104(3):378–388. . Computer-
based psychological treatment for comorbid depression
and problematic alcohol and/or cannabis use: a randomized
controlled trial of clinical efficacy.