Common Mental Disorders Depression - New Zealand Doctor

psychological therapies were of equivalent efficacy to other treatments (in most cases
antidepressants and GP care), but were better tolerated.
A recent New Zealand study 388 compared CBT and IPT in 177 outpatients with
depression and found CBT and IPT equally effective for mild and moderate
depression, with about 55% of patients experiencing at least a 60% reduction in
symptom scores over 16 weeks. Cognitive behavioural therapy was more effective than
IPT in severe depression. Melancholia did not predict poor response to either therapy.
Other evidence from mixed settings suggests that CBT, IPT and BT are as effective as
antidepressants 65,331-333 and that CBT and BT may have a longer-lasting effect. 65,389
Both IPT and CBT may be useful as a maintenance treatment. 65 Combined therapy
with CBT and antidepressants may enhance the effectiveness and tolerability
of treatment, particularly for people with more severe depression 65 and may also
reduce relapse rates in patients with residual symptoms. 65
A 2006 meta-regression of studies from a variety of settings found that the mode
of delivery of CBT did not impact on its effectiveness, although the evidence for
telephone and computerised CBT was limited. 390 It was unclear to what extent the
professional background of the therapist affected efficacy: it was clear that trained
psychologists delivered effective therapy, but there was insufficient evidence to
determine the effect of delivery by other health care practitioners. 390
Psychological therapies: issues for evidence-based practice
The evidence on psychological therapies applies to ‘textbook’ approaches which target
depression and have a behavioural element, such as CBT, BT, IPT, MBCT and PST.
The GDT notes that in practice most therapists use a less structured approach than the
methods used in research and it is unclear whether this influences clinical outcomes.
Given the resource problems with formal therapy, it may be useful for members of
primary care teams to develop the skills to teach simple cognitive strategies such
as PST, activity scheduling and goal-directed therapy. Ideally, these therapies will
be provided within primary care, 352 but some skills may need to be introduced from
elsewhere. Any psychological therapy offered in the treatment of depression should
use a recognised therapeutic approach (eg, CBT, IPT or PST) which focuses on
depression, resilience and behavioural support, or includes components targeted to
the individual’s specific problem. 9,65
Other features likely to affect outcomes but which have not been subject to controlled
comparison are a good therapeutic relationship and (on the part of the patient)
motivation, positive expectations and receptiveness to the therapeutic model. 391
The NICE (2004) findings on non-specific counselling derive from three studies of
widely differing and eclectic approaches and need to be viewed with caution. In the
opinion of the GDT, psychological therapies that encourage rumination may not be
helpful for people with depression and may potentially cause harm. Currently, there
is a trend towards the use of specific interventions such as behavioural activation, a
type of behavioural therapy that is a component of CBT. In the opinion of the GDT,
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Identification of Common Mental Disorders and Management of Depression in Primary Care