Common Mental Disorders Depression - New Zealand Doctor

Secondary care evidence
Based on evidence from secondary care, a US health technology assessment 448 concluded
that the accuracy of assessment tools for depression used in women with postnatal
depression was fairly consistent with results reported for their use in general primary care
settings. However, the authors noted that the lack of precision in the results, particularly
with respect to diagnostic sensitivity, precluded the recommendation of any particular
screening instrument or any particular cut off. Based on similar evidence, the Scottish
Intercollegiate Guidelines Network (SIGN) 2002 guideline 449 recommends the routine
use of the EPDS for screening for postnatal depression but notes that the EPDS is not a
diagnostic tool and that the diagnosis of postnatal depression requires clinical evaluation.
Screening and assessment:
issues for evidence-based practice
There is evidence that postnatal depression is inadequately recognised and treated
in New Zealand. 446 In view of the potentially very serious consequences of failure to
identify a mental disorder in women in the antenatal or postnatal period, a policy of
targeted screening for mental disorders in all women in the antenatal or postnatal
period is recommended. At a pregnant woman’s first contact with primary care, at
her maternity care ‘booking’ visit and 6-week postnatal check, practitioners should
consider asking questions that screen for depression as part of routine assessment. 101
In the opinion of the GDT, the practitioner should also consider using questions to
screen for anxiety and substance use (see Box 5.2).
For around 22% of women with postnatal depression, onset may occur later than 6 weeks
after childbirth. 450 The infant’s 3-month or 5-month immunisation visit presents a further
opportunity for maternal screening. 447 The GDT notes that maternal screening may in
future become part of Ministry of Health recommendations for Well Child packages.
Although the verbal 2–3 question screening tools have not been evaluated specifically
for use in the antenatal or postnatal period, they have been validated for identifying
common mental disorders in adults in primary care (see 5.4 Assessment Tools:
Evidence Review). Moreover, there is evidence that targeted screening of selected
high-risk adults is feasible, that it increases the identification rate of common mental
disorders in adults in primary care and also increases the likelihood of general
practitioner intervention (see 5.2: Targeted Screening of High-risk Groups, Targeted
Screening: Evidence Review). Women in the antenatal and postnatal period are
regarded as a high-risk group because mental disorders occurring during pregnancy
and the postnatal period may have greater adverse consequences for all concerned
than they do at other times. 101 The GDT notes that, in this population as in others,
routine screening needs to be accompanied by easy access to effective and acceptable
treatment where required, and that research is needed to determine whether screening
for common mental health disorders results in improved long-term outcomes.
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Identification of Common Mental Disorders and Management of Depression in Primary Care