When a person has subthreshold depression they typically display a group of depressive symptoms but the number, duration, or quality of the symptoms are not present in a sufficient scale to meet the criteria for a diagnosis of major depression.
In the new study, adults with subthreshold depression were randomly assigned to receive either usual care in which there was no psychological intervention (n=116) or a behavioral activation focused on mindfulness training (n=115).
Intervention participants were invited to attend weekly two-hour mindfulness training sessions for eight consecutive weeks.
After a year of training, there was a statistically significant difference in the incidence of major depressive disorder between groups (11 percent in the mindfulness group compared to 27 percent in usual care).
Investigators also discovered mindfulness training had a small effect in reducing depression symptoms (between-group mean difference = 3.85). Other secondary outcomes demonstrated no significant change.
Researchers suggest that, for patients with subthreshold depression who have not had a major depressive episode in the past six months, mindfulness training is a feasible method of preventing major depression.
Future research will compare cost-effectiveness, health service use implications, and acceptability of mindfulness training.
The study appears in the journal Annals of Family Medicine.
Source: Annals of Family Medicine