Do your homework, do better in treatment?

Previous research has shown homework completion in addiction treatment is related to better outcomes. This could simply be a marker of success, however, rather than a cause of it. This study helped shed some light on how strongly homework completion actually relates to positive treatment response.

YOUR ASSIGNMENT: Read more and discover what the researchers found.


A major assumption in virtually all psychosocial approaches for psychiatric disorders, including substance use disorder, is that the patient does work outside of the therapy session. This outside work – often referred to as “homework” – is intended to help apply new skills learned and practiced in treatment to real-world experiences, as well as to help internalize insights and progress into one’s day to day thinking, feeling, and behavior.


As might be expected, previous research shows the better someone adheres to their homework, the better their substance use outcomes. This research, however, has not been able to rule out whether this homework completion could simply reflect overall motivation to make a change, commitment to treatment, or the working alliance (e.g., relationship) with the therapist. In turn, it could be that each of these factors, rather than the homework completion itself, was accounting for the positive effects of homework completion on better outcomes.

This study by Decker and colleagues helped to address this limitation with prior studies. Study authors investigated the effect of homework completion, above and beyond individuals’ demonstrated commitment to treatment, measured in this study by how many treatment sessions they attended.


The study combined data from four previous randomized controlled trials of cognitive-behavioral therapy for cocaine use disorder. Three of the studies (1, 2, & 3) tested a 12-week face-to-face treatment, as well as 1-, 3-, 6-, and 12-month follow-ups, and the fourth tested an 8-week computerized treatment, with 1-, 3-, and 6-month follow-ups.

This study included just the 158 individuals who attended at least two sessions – to provide a chance to report whether they completed the homework assignment from the previous session.


Homework completion was measured by the number of assignments completed divided by the total assignments received and checked, which was then converted to an ordinal category:



As mentioned above, the primary analysis controlled for the percentage of sessions attended out of the total possible number of sessions attended (either 12 or 8). The main outcomes were percent days abstinent from cocaine (by self-report) and the percentage of cocaine-negative urine drug tests. Regarding participant characteristics, on average they used cocaine 14 of 28 days upon entering the study (SD = 8.5).

In addition to cocaine use disorder, 81% also had alcohol use disorder, 30% with antisocial personality disorder, 22% major depressive disorder, and 11% anxiety disorder in their lifetime. They were mostly male (73%), with relatively equal proportions of White (46%) and Black (43%) individuals by race; 42% were employed and, regarding education level, 81% completed high school or greater.



Better homework completion was related to better outcomes during cocaine treatment, even when controlling for patients’ treatment attendance & how severe they were at baseline.

Taking these other factors in account, homework completion explained 17% of individuals’ cocaine abstinence during treatment.


Post-treatment results were more mixed. While the effect of homework completion on whether an individual had a negative drug test (i.e., positive result) at the follow-up was significant at 3-months post-treatment and just missed significance at 6 months post-treatment, it was not significant at the 1 or 12-month follow-ups.

In terms of the real-world meaning of these results, if someone had 10 assignments during treatment and completed 10 drug tests, compared to patients who completed 1 to 4 of these assignments, individuals who completed five or more had 2.1 more negative drug tests during treatment (out of 10) and a 20% greater chance of a negative drug test at 3-month follow-up.


The result that homework completion can impact treatment outcomes in cognitive-behavioral therapy for cocaine use disorder is certainly not unexpected. That said the fact that it remains important even when someone’s initial severity and their treatment attendance is taken into account is an important clinical research finding.

Study authors theorize that homework completion could be a marker of skill acquisition (e.g., do they feel competent at being able to implement assertive drink and other drug refusal), or perhaps how well one can implement the skill in their day to day life.

Although the quantity of one’s coping skills has, somewhat counterintuitively, not been found to explain the benefit of cognitive behavioral therapy in research, one recent study suggests that the quality of these coping skills – rather than quantity – may explain some of its benefit.

  1. There were many factors that were not measured in this study, and could account for the apparent effect of homework completion on better outcomes. For example, personality traits of conscientiousness and agreeableness (i.e., the extent to which someone complies with authority or expectations) could be important, as individuals high in these traits would be more likely to complete homework, and perhaps more likely to abstain or reduce cocaine use to please their therapist or adhere to treatment expectations.
  2. Another key missing variable was age, as many – but not all – studies show older age is related to better treatment outcomes.
  3. It is worth mentioning that homework completion was not related to gender, race, education level, referral to the study treatment by the criminal justice system, prior mental health treatment, or the presence of another psychiatric disorder in addition to substance use disorder. This suggests these factors did not account for the effect of homework completion on better cocaine outcomes in this study.


Next steps would be to investigate why homework completion is important to better outcomes. Does more completion lead to better and more quality skills acquisition? Could homework completion help reinforce the motivation and confidence to abstain from, or reduce substance use? These and other questions will be important to investigate in future studies.


  • For individuals & families seeking recovery: If you or your loved one is receiving psychosocial treatment for substance use disorder, completing your outside activities – sometimes referred to as homework assignments – is likely to improve your chances of a positive outcome.
  • For Scientists: This study showed that homework completion is uniquely related to positive outcomes in cognitive behavioral therapy for cocaine use disorder, over and above initial severity and treatment attendance. Future studies may use mediation models to understand better exactly why homework completion is helpful, so that its usefulness in treatment can be maximized. Furthermore, this study suggests that treatment engagement may consist of several components, such that, at a minimum, homework completion should be measured in addition to treatment attendance.
  • For Policy makers: Patient engagement in treatment can be measured in several ways. This study showed that both homework completion and treatment attendance may be important predictors of how well a patient responds to treatment. Policies and funding to help treatment programs measure their patients’ treatment engagement in a multitude of ways could prove fruitful in terms of helping target and leverage the most important aspects of therapy.
  • For Treatment professionals and treatment systems: Patient engagement in treatment can be measured in several ways. This study showed that both homework completion and treatment attendance may be important predictors of how well a patient responds to treatment. Given available resources, consider tracking patients’ engagement using a multitude of variables, including but not limited to their treatment attendance and completion of outside activities, often referred to as homework.


Decker, S. E., Kiluk, B. D., Frankforter, T., Babuscio, T., Nich, C., & Carroll, K. M. (2016). Just showing up is not enough: Homework adherence and outcome in cognitive–behavioral therapy for cocaine dependence. Journal of Consulting and Clinical Psychology, 84(10), 907.