Therapeutics•

Problem-solving therapy reduces disability more than supportive therapy in older adults with major depression and executive dysfunction

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Question

Is problem-solving therapy (PST) better than supportive therapy (ST) for reducing disability in older adults with depression and executive dysfunction?

Patients

221 older adults (aged >59 years) with major non-psychotic depression (Structured Clinical Interview for Axis-I DSM-IV disorders), 24-item Hamilton Depression Rating Scale score ≥20, Mini-Mental State Examination score ≥24, Mattis Dementia Rating Scale initiation/preservation domain (DRS-IP) score ≤33 and Stroop Colour-Word Test score ≤25.

Setting

Two research centres (Weill Cornell Medical College and University of California at San Francisco), USA; 2002–2007.

Intervention

PST versus ST for 12 weeks. PST was delivered individually over 12, once-weekly sessions and followed the unpublished manual, Social Problem Solving Therapy for Depression and Executive Dysfunction, which is based on setting and achieving goals, creating action plans and evaluating the accomplishment of goals. The first five sessions were educational, the subsequent seven based on enhancing skills and the final two on a relapse-prevention plan. Experienced clinical psychologists or licensed social workers received specific training in the delivery of each intervention.

Outcomes

Disability assessed using the 12-item WHO Disability Assessment Schedule II (WHODAS II), which gives a composite score across domains of understanding and communicating, getting around, self-care, household and work activities, getting along with others and participation in society. Assessments were carried out at baseline, weekly during the 12-week intervention (disability during treatment) and then at weeks 24 and 36 (disability after treatment). Between-group score differences were compared using mixed-effects models for longitudinal data; the models included treatment group, treatment site, time trend, and site × treatment and time × treatment interactions.

Patient follow-up

93.2% assessed at 12 weeks, 78.3% at 24 weeks and 75.6% at 36 weeks. 100% included in intention-to-treat analysis.

Methods

Design

Randomised controlled trial.

Allocation

Unclear.

Blinding

Single blinded (outcome assessors blinded, but not therapists or participants).

Follow-up period

36 weeks (12-week intervention period and 24-week postintervention follow-up).

Main results

Although both groups showed reductions in disability during treatment, PST reduced disability more than ST over the 12-week period (treatment × time interaction: p=0.01). Overall, PST gave about an 0.18 points-per-week greater reduction in total disability score than ST over 12 weeks (average baseline WHODAS II score 26.6; week 12 least squares means scores: 21.6 with PST vs 23.7 with ST). Moderator analyses demonstrated that PST had a greater effect in people with more previous depressive episodes and greater cognitive impairment. After treatment completed, both groups demonstrated an increase in disability score (p=0.03), with no difference between the groups in the course of disability (treatment × time interaction: p=0.66). This meant that the score difference between the groups was maintained (least squares means WHODAS II scores at 24 weeks: 22.5 with PST vs 24.5 with ST and at 36 weeks: 23.4 with PST vs 25.2 with ST).

Conclusions

In older adults with major depression and executive dysfunction, a 12-week PST intervention reduces disability more than ST. Although disability increases again after treatment completion, the difference between the treatments is maintained.

Abstracted from

AlexopoulosGS, RauePJ, KiossesDN, et al. Problem-solving therapy and supportive therapy in older adults with major depression and executive dysfunction: effect on disability.Arch Gen Psychiatry2011;68:33–41.

Sources of funding: National Institute of Mental Health and the Sanchez Foundation.

Commentary

The reciprocal relationship between late-life depression and disability is complex: depression is one of the major causes of disability, but disability due to physical illness often causes depression. In this study, Alexopoulos and colleagues investigate the effect of non-pharmacologic treatment of late-life depression on disability. They have reported in a previously published article1 that problem-solving therapy (PST) as well as supportive therapy (ST) reduced depressive symptoms in a sample of 221 older patients with major depression and executive dysfunction. However, PST was associated with greater improvement and higher rates of response and remission than ST. In this new analysis of the same study, they found that PST and ST also reduce disability. PST is superior to ST, but the effect size is small: the difference between the two therapies in score reduction on the WHO Disability Assessment Schedule II (WHODAS II) is only 2.3 points, or less than 10% of the baseline score of the study group (26.6) and less than one-third of the corresponding SD (7.6). Improvement in depression scores predicts improvement in disability (WHODAS II) scores the following week. Similarly, improvement in disability predicts improvement in depression the following week. However, although the difference in depression scores between PST and ST does not explain the difference in disability score, the difference in disability partially explains (mediates) the difference in depression score.

The authors argue convincingly that this reciprocal relationship does not solely reflect reporting bias, that is, patients whose depression is improving report better function. Taking into account the timing of the observed improvement, PST appears successful at motivating and activating older depressed patients. In turn, the resulting increased perception of self-efficacy leads to optimism and reduction in depressive symptoms. This mechanistic interpretation of the results of this study is congruent with some of the hypothesised ways in which cognitive-behavioural therapy (CBT) treats mid-life depression. Most older depressed patients do not have access to experienced psychotherapists formally trained in the administration of PST (or CBT). However, all health professionals who treat these patients can incorporate in their therapeutic interactions some of the behavioural ingredients of PST (or CBT).

Competing interests: None.

Areán PA, Raue P, Mackin RS, et al. Problem-solving therapy and supportive therapy in older adults with major depression and executive dysfunction. Am J Psychiatry 2010; 167:1391–8.
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