Procrastination is a common problem among university students, with at least half of the population reporting great difficulties initiating or completing certain tasks and assignments. Procrastination can have a negative impact on course grades and the ability to achieve a university degree, but can also lead to psychological distress, such as, stress and anxiety. Cognitive Behavior Therapy (CBT) is often considered treatment of choice, but few studies have investigated its effectiveness in regular clinical settings.

The current study explored its treatment effects using a pragmatic randomized controlled trial comparing treatment delivered during eight weeks as unguided self-help via the Internet (ICBT) or as group CBT. In total, 92 university students with severe procrastination were included in the study (registered as a clinical trial on Clinicaltrials.gov: NCT02112383). Outcome measures included self-reported procrastination, depression, anxiety, and physical and psychological well-being, which were distributed at pre- and posttreatment, as well as six-month follow-up. An outcome measure of procrastination was also administered weekly. Linear mixed and fixed effects models were calculated, along with improvement and deterioration rates.

The results showed that both unguided ICBT and group CBT yielded large within-group effect sizes on procrastination, Cohen's d = 1.24- 1.29, 95% Confidence Interval (CI) [0.76- 1.74], and small to moderate benefits for depression, anxiety, and well-being, d = 0.37-0.68, 95% CI [-0.06-1.12]. In total, 32.6% were improved at post-treatment and 45.6% at follow- up. No differences between conditions were observed directly after the treatment period, however, participants in group CBT continued or maintained their improvement at follow- up, while participants in unguided ICBT showed signs of deterioration. The findings from the current study suggest that CBT might be an effective treatment for students with problems of procrastination, but that a group format may be better for some in order to sustain their benefits over time. Procrastination is a common problem among university students, but few clinical trials have investigated the efficacy of different treatment interventions for this condition. The current study compared the results of CBT delivered as an unguided Internet-based treatment and CBT distributed in groups. The findings suggest that a both formats is beneficial for many individuals with difficulties of procrastination, but that group CBT could be better for some, at least in the long-run. Together with a previous randomised controlled trial of CBT for procrastination evidence now looks promising with regard to providing effective treatments for this condition, but more research is warranted in terms of improving the results and to evaluate the benefits using also behavioural measures.