In the UK, primary care (as the name suggests) is the first port of call for most people seeking to access healthcare support, including any care or advice they may need for mental distress. Depressive experiences are common and therefore many people will speak with primary care doctors and other professionals about these difficulties.

The NICE depression pathway recommends that individuals seeking support in relation to depression be offered a combination of psychotherapy and pharmacotherapy. Much of the burden of this care and support falls on primary care, so it’s vital that we have reliable evidence about the safety and effectiveness of talking treatments, so that GPs can confidently refer patients.

Systematic reviews, such as the recent publication by Linde and colleagues (2015), provide us with a means of summarising and synthesising the best available evidence. Along with patient values and preferences and clinical experience, they are an important component for any evidence-based clinical decision.

The authors sought to review existing literature regarding the efficacy of psychotherapy in relation to usual care or placebo in a population drawn from primary care settings. They also wished to explore the efficacy of differing psychotherapy modalities and delivery models.

Methods

• This report represents a component of a larger study assessing the efficacy of both psychotherapy and pharmacotherapy in primary care settings (We’ll be blogging about the pharmacotherapy review separately on the Mental Elf in the near future)
• The authors undertook a systematic search of the published literature
• They identified randomised control trials that compared psychotherapy with usual care or placebo in adults with depressive experiences
• Studies were selected that recruited through direct referral from primary care, or through systematic waiting room screening
• Trials were subdivided according to their delivery method and therapeutic modality

Bias

• Risk of bias was appraised using a standardised measure, although measures relating to blinding of participants or providers were excluded owing to the complexity of applying these measures in psychological therapies
• Included trials were ranked according to their risk of bias (low, high or uncertain)

Outcomes

• Where available participant measured ratings were used (e.g. the Beck Depression Inventory), observer rated scales were used where these measures were not available
• Response was defined as a 50% reduction in symptom severity, remission as a reduction in severity score to below a specified level
• Acceptability of the interventions were measured through study drop-out rates and, where possible, through records of adverse events in the study

Meta-analysis

• Post-treatment rating differences between treatment and control groups were combined together in a meta-analysis
• Odds ratios were calculated for outcomes such as remission or withdrawal from trial
• Variation between study findings (heterogeneity) were measured and reported

Results 

• 30 studies were included in the meta-analysis, with a total of 5,159 participants overall
• 27 of the included studies had a ‘usual care’ control group
• Most trials incorporated CBT as the therapeutic intervention in some form:
  • Face-to-face
  • Remote therapist led
  • Guided self-help CBT
  • No contact CBT (e.g. computer based)

Bias

• 10 trials were felt to be at low risk of bias
• 9 were uncertain
• 11 were high risk

Clinical characteristics

• Baseline depression rating scores were not reported in this analysis
• The longest follow up period was 26 weeks and this was in only 3 of the reported trials

Effectiveness findings

• Meta-analysis for most therapies demonstrated small to moderate benefits of psychotherapy over control group, although few individual studies showed statistically significant evidence of efficacy
• Face-to-face problem solving therapy and remote problem solving therapy did not demonstrate this effectiveness
• Most of the included studies showed a moderate to high variation in their findings, with the exception of face-to-face CBT and interpersonal psychotherapy which were reported as having no variation in findings. Although a visual inspection of the scatter of results in the case of CBT trials would suggest this could be a reporting mistake
• Analysis of the findings in terms of remission of symptoms could only demonstrate effectiveness in two therapeutic subgroups:
  • Other face-to-face psychological therapies
  • Guided self-help CBT

Acceptability

• No difference was observed between drop out rates in intervention or control groups for any subgroup
• There was insufficient reporting on adverse events to draw any conclusion in relation to possible therapy side-effects

Publication bias

• Inspection of the published study results suggests that a positive publication bias may be present, but there were insufficient studies to comment on individual therapy modalities

Conclusions

The authors state:

There is evidence that psychological treatments are effective in depressed primary care patients. For CBT approaches, substantial evidence suggests that interventions that are less resource intensive might have effects similar to more intense treatments.

Discussion

So what are we to make of this synthesis of the available evidence? It seems clear that psychotherapy has a small to moderate effect for people accessing primary care in relation to depressive symptoms. However, what can we say beyond this?

That this study reviews the available evidence in relation to primary care is important, as this is where many people seek help without necessarily receiving referrals into the mental health services. Embedding mental health expertise within primary care is clearly of importance.

However the number of participants within these studies is small, as usual the length of follow up is short, with only three trials reaching 6 months follow up. There is no indication of whether the authors of this analysis considered handling of longer term data in their analysis. The variation of findings between trials is also significant, for example for face-to-face CBT only one included trial showed a statistically significant effect and this only included 34 participants. Finally the risk of bias in reported trials was high or unclear in the majority of cases.

Overall the message remains the same. Depressive experiences are intensely personal in nature and often deep routed in their implications. Simple measures such as severity rating do not adequately capture this experience and while of use in clinical trials, more complex assessments are essential if we are to adequately capture individual experience.

We need better quality evidence that follows individual experience over longer periods of time before we can begin to truly understand the implications of varying psychotherapy, and other treatment, options.

Links

Linde K et al. Effectiveness of Psychological Treatments for Depressive Disorders in Primary Care: Systematic Review and Meta-Analysis. Ann Fam Med 2015 Jan;13(1):56-68.

National Institute for Health and Care Excellence – Depression care pathway.