Background: An earlier paper reported positive outcomes immediately following access to a cognitive-behavioural therapy (CBT) internet intervention and a depression information website.
Aims: To determine 6-month and 12-month outcomes of the interventions relative to a placebo control condition.
Method: Participants allocated to the depression information website condition, the CBT internet intervention and the placebo control condition were followed up at 6 and 12 months by survey. The primary outcome measure was the Center for Epidemiologic Studies-Depression (CES-D) scale. Of 525 participants recruited, 79% completed their assigned intervention and 60% were retained at 12-month follow-up. Attrition was handled using mixed-model repeated-measures ANOVA.
Results: Both the CBT site and depression information sites were associated with statistically significant benefits in CES-D score reduction compared with controls at post-test. At 6-months follow-up, the reduction seen for the people allocated to the CBT arm remained significant, whereas that for the depression information website arm was not. At 12 months, both active interventions were statistically significantly superior to the control condition.
Conclusions: There is some evidence that benefits of these brief internet interventions are retained beyond their endpoint. The impact of human support provided by interviewers in the trial must be considered when comparing these outcomes to routine use of both internet interventions.