Cost-effective treatments are needed to reduce the burden of depression. One way to improve the cost-effectiveness of psychotherapy might be to increase session frequency, but keep the total number of sessions constant.

To evaluate the cost-effectiveness of twice-weekly compared with once-weekly psychotherapy sessions after 12 months, from a societal perspective.

An economic evaluation was conducted alongside a randomised controlled trial comparing twice-weekly versus once-weekly sessions of psychotherapy (cognitive–behavioural therapy or interpersonal psychotherapy) for depression. Missing data were handled by multiple imputation. Statistical uncertainty was estimated with bootstrapping and presented with cost-effectiveness acceptability curves.

Differences between the two groups in depressive symptoms, physical and social functioning, and quality-adjusted life-years (QALY) at 12-month follow-up were small and not statistically significant. Total societal costs in the twice-weekly session group were higher, albeit not statistically significantly so, than in the once-weekly session group (mean difference €2065, 95% CI −686 to 5146). The probability that twice-weekly sessions are cost-effective compared with once-weekly sessions was 0.40 at a ceiling ratio of €1000 per point improvement in Beck Depression Inventory-II score, 0.32 at a ceiling ratio of €50 000 per QALY gained, 0.23 at a ceiling ratio of €1000 per point improvement in physical functioning score and 0.62 at a ceiling ratio of €1000 per point improvement in social functioning score.

Based on the current results, twice-weekly sessions of psychotherapy for depression are not cost-effective over the long term compared with once-weekly sessions.

Twice weekly sessions of cognitive behavioral therapy (CBT) and interpersonal psychotherapy (IPT) for major depressive disorder (MDD) lead to less drop-out and quicker and better response compared to once weekly sessions at posttreatment, but it is unclear whether these effects hold over the long run.

Compare the effects of twice weekly v. weekly sessions of CBT and IPT for depression up to 24 months since the start of treatment.

Using a 2 × 2 factorial design, this multicentre study randomized 200 adults with MDD to once or twice weekly sessions of CBT or IPT over 16–24 weeks, up to a maximum of 20 sessions. Main outcome measures were depression severity, measured with the Beck Depression Inventory-II and the Longitudinal Interval Follow-up Evaluation. Intention-to-treat analyses were conducted.

Compared with patients who received once weekly sessions, patients who received twice weekly sessions showed a significant decrease in depressive symptoms up through month 9, but this effect was no longer apparent at month 24. Patients who received CBT showed a significantly larger decrease in depressive symptoms up to month 24 compared to patients who received IPT, but the between-group effect size at month 24 was small. No differential effects between session frequencies or treatment modalities were found in response or relapse rates.

Although a higher session frequency leads to better outcomes in the acute phase of treatment, the difference in depression severity dissipated over time and there was no significant difference in relapse.

It is unclear what session frequency is most effective in cognitive–behavioural therapy (CBT) and interpersonal psychotherapy (IPT) for depression.

Compare the effects of once weekly and twice weekly sessions of CBT and IPT for depression.

We conducted a multicentre randomised trial from November 2014 through December 2017. We recruited 200 adults with depression across nine specialised mental health centres in the Netherlands. This study used a 2 × 2 factorial design, randomising patients to once or twice weekly sessions of CBT or IPT over 16–24 weeks, up to a maximum of 20 sessions. Main outcome measures were depression severity, measured with the Beck Depression Inventory-II at baseline, before session 1, and 2 weeks, 1, 2, 3, 4, 5 and 6 months after start of the intervention. Intention-to-treat analyses were conducted.

Compared with patients who received weekly sessions, patients who received twice weekly sessions showed a statistically significant decrease in depressive symptoms (estimated mean difference between weekly and twice weekly sessions at month 6: 3.85 points, difference in effect size d = 0.55), lower attrition rates (n = 16 compared with n = 32) and an increased rate of response (hazard ratio 1.48, 95% CI 1.00–2.18).

In clinical practice settings, delivery of twice weekly sessions of CBT and IPT for depression is a way to improve depression treatment outcomes.

Psychotherapies for depression are equally effective on average, but individual responses vary widely. Outcomes can be improved by optimizing treatment selection using multivariate prediction models. A promising approach is the Personalized Advantage Index (PAI) that predicts the optimal treatment for a given individual and the magnitude of the advantage. The current study aimed to extend the PAI to long-term depression outcomes after acute-phase psychotherapy.

Data come from a randomized trial comparing cognitive therapy (CT, n = 76) and interpersonal psychotherapy (IPT, n = 75) for major depressive disorder (MDD). Primary outcome was depression severity, as assessed by the BDI-II, during 17-month follow-up. First, predictors and moderators were selected from 38 pre-treatment variables using a two-step machine learning approach. Second, predictors and moderators were combined into a final model, from which PAI predictions were computed with cross-validation. Long-term PAI predictions were then compared to actual follow-up outcomes and post-treatment PAI predictions.

One predictor (parental alcohol abuse) and two moderators (recent life events; childhood maltreatment) were identified. Individuals assigned to their PAI-indicated treatment had lower follow-up depression severity compared to those assigned to their PAI-non-indicated treatment. This difference was significant in two subsets of the overall sample: those whose PAI score was in the upper 60%, and those whose PAI indicated CT, irrespective of magnitude. Long-term predictions did not overlap substantially with predictions for acute benefit.

If replicated, long-term PAI predictions could enhance precision medicine by selecting the optimal treatment for a given depressed individual over the long term.

Although equally efficacious in the acute phase, it is not known how cognitive therapy (CT) and interpersonal psychotherapy (IPT) for major depressive disorder (MDD) compare in the long run. This study examined the long-term outcomes of CT v. IPT for MDD.

One hundred thirty-four adult (18–65) depressed outpatients who were treated with CT (n = 69) or IPT (n = 65) in a large open-label randomized controlled trial (parallel group design; computer-generated block randomization) were monitored across a 17-month follow-up phase. Mixed regression was used to determine the course of self-reported depressive symptom severity (Beck Depression Inventory II; BDI-II) after treatment termination, and to test whether CT and IPT differed throughout the follow-up phase. Analyses were conducted for the total sample (n = 134) and for the subsample of treatment responders (n = 85). Furthermore, for treatment responders, rates of relapse and sustained response were examined for self-reported (BDI-II) and clinician-rated (Longitudinal Interval Follow-up Evaluation; LIFE) depression using Cox regression.

On average, the symptom reduction achieved during the 7-month treatment phase was maintained across follow-up (7–24 months) for CT and IPT, both in the total sample and in the responder sample. Two-thirds (67%) of the treatment responders did not relapse across the follow-up period on the BDI-II. Relapse rates assessed with the LIFE were somewhat lower. No differential effects between conditions were found.

Patients who responded to IPT were no more likely to relapse following treatment termination than patients who responded to CT. Given that CT appears to have a prophylactic effect following successful treatment, our findings suggest that IPT might have a prophylactic effect as well.

There appears to be consensus that patients with only one or two prior depressive episodes do not benefit from treatment with mindfulness-based cognitive therapy (MBCT).

To investigate whether the effect of MBCT on residual depressive symptoms is contingent on the number of previous depressive episodes (trial number NTR1084).

Currently non-depressed adults with residual depressive symptoms and a history of depression ($2 prior episodes: n = 71; $3 episodes: n = 59) were randomised to MBCT (n = 64) or a waiting list (control: n = 66) in an open-label, randomised controlled trial. The main outcome measured was the reduction in residual depressive symptoms (Hamilton Rating Scale for Depression, HRSD-17).

Mindfulness-based cognitive therapy was superior to the control condition across subgroups (β =–0.56, P<0.001). The interaction between treatment and subgroup was not significant (β = 0.45, P = 0.16).

Mindfulness-based cognitive therapy reduces residual depressive symptoms irrespective of the number of previous episodes of major depression.

Daily-life stress sensitivity is associated with depression, but prospective data are lacking.

To examine associations between baseline ecological daily-life stress sensitivity and later depression, and to identify genetic and non-genetic factors moderating the transition from stress sensitivity to depression.

Daily-life stress sensitivity was assessed at baseline in twins (n = 502). One baseline and four follow-up measurements of depressive symptoms and negative life events were collected, as well as interview-based diagnoses at baseline and last follow-up. Hypothesised genetic markers were determined.

Baseline stress sensitivity was associated with increased depressive symptoms at follow-up and risk of major depressive disorder. Both genetic liability and major life events moderated the probability of transition from stress sensitivity to depression.

Onset of depression is attributable to pre-onset ecological measurements of stress sensitivity, particularly where genetic liability is high and individuals have reached a stage where the influence of competing environmental causes is low.

A bias to develop negative affect in response to daily life stressors may be an important depression endophenotype, but remains difficult to assess.

To assess this mood bias endophenotype, uncontaminated by current mood, in the course of daily life.

The experience samping method was used to collect multiple appraisals of daily life event-related stress and negative affect in 279 female twin pairs. Cross-twin, cross-trait associations between daily life mood bias and DSM – IV depression were conducted.

Probands whose co-twins were diagnosed with lifetime depression showed a stronger mood bias to stress than those with co-twins without such a diagnosis, independent of probands' current depressive symptoms and to a greater extent in monozygotic twins than in dizygotic twins.

Genetic liability to depression is in part expressed as the tendency to display negative affect in response to minor stressors in daily life. This trait may represent a true depression endophenotype.