Page 12 - The SA Journal Diabetes & Vascular Disease Volume 9 No 4 (November 2012)

154 VOLUME 9 NUMBER 4 • NOVEMBER 2012
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specialists, 71 responded and only approximately 30% indicated that
they would screen their patients for comorbid MDD.13 Low recognition
of comorbid depression in diabetes by non-psychiatric physicians
has also been described in the USA.14 In the UK, a survey performed
among doctors and nurses in 464 UK diabetes centres assessed the
availability of psychological services for people with diabetes in the
UK, as well as compliance with national guidelines and skills of the
diabetes team in psychological aspects of diabetes management.15 Of
these, 267 responded and 53 were interviewed. Less than one-third
(84) of the responding centres had access to specialist psychological
services, over two-thirds (182) of the centres had not implemented the
majority of national guidelines and only 2.6% of the centres met all
the guidelines. Most (81%) expert providers interviewed by telephone
were under-resourced to meet the psychological needs of their
patients. The authors concluded that expert psychological support was
not available to the majority of diabetes centres.
Nevertheless, not many studies have been performed evaluating
the effect of screening for MDD in diabetes mellitus. Some studies
have screened for MDD in the primary care setting. A study by
Valenstein et al. reported that annual and periodic screening for
MDD in the primary care setting cost more than $50 000/QALY,
but that one-off screening was cost effective.16 They suggested that
cost effectiveness of screening may improve if treatment becomes
more effective. A Cochrane review and meta analysis performed by
Gilbody et al. concluded that if used without further instruction or
support for the clinician, case-finding or screening questionnaires
for depression had little impact on the detection and management
of depression by clinicians.17
As there is a clear discrepancy between the needs of the patients
and the actual clinical practice concerning screening, this article
describes the rationale and requirements for screening and suggests
a practical approach for the clinical setting that may meet the needs
of people with comorbid diabetes and depression.
Requirements for screening
Screening procedures require (1) a clear description of the condition
for which screening is needed, (2) availability of effective treatment
as follow-up strategy to the screening, (3) a valid instrument for
detecting the condition by screening, and (4) persons with diabetes
willing to collaborate with screening and follow-up treatment. This
implies that screening should be followed by proposing a suitable
treatment to persons with diabetes diagnosed with comorbid MDD.
Description of the condition
As screening should be followed by proper treatment advice
and persons with diabetes should be eager to follow this advice,
screening should aim to identify not only if depressive symptoms are
present, but also the severity of the symptoms in terms of burden
for the patient, given that high symptom burden is associated with
motivation to be treated. Preferably, the instrument should be
able to detect if depressive symptoms are present and if they can
be classified as an MDD as described in Diagnostic and Statistical
Manual of Mental Disorders (4th edn) (DSM-IV). 18 The main criteria
are shown in Table 1.
Availability of effective treatment
A recent systematic review and meta-analysis established that in
general, treatment of comorbid MDD in persons with diabetes is
more effective than usual care.19 Providing treatment for comorbid
MDD in persons with diabetes improves depressive symptoms
to a large extent, no matter which treatment is provided, i.e.
psychotherapy with self-management, pharmacotherapy or
collaborative care.17 However, this does not automatically improve
glycaemic control and specific interventions are needed for that.17
Antidepressants
Several studies have evaluated the effects of antidepressants in
patients with comorbid MDD in diabetes. Fluoxetine, sertraline,
nortriptyline and paroxetine have been reported to significantly
improve depressive symptoms.20 Fluoxetine is associated with
weight loss, lower glucose and blood lipids.21 Sertraline is effective
in relapse prevention. 22 Sertraline and paroxetine improve comorbid
anxiety, quality of life and general functioning.23 However, these
antidepressants show no influence on glycaemic control except
for sertraline which reduced glycated haemoglobin A1 c (HbA1 C)
compared with baseline and placebo.24 The mechanism of this
effect of sertraline is unknown. In general, the studies are small and
therefore, further research in this field is certainly needed. 13
Valid instruments for screening
On top of the criteria mentioned above, DSM-IV diagnosis of MDD
requires that the symptoms do not include those that are clearly due
to a general medical condition. In the case of persons with diabetes
a screening instrument would therefore be required to discern
between symptoms of MDD and those of diabetes. Studies should
be available that test the validity of instruments in identifying MDD
in patients with diabetes, assessing the instrument in patients with
diabetes and comparing this to the gold standard for diagnosis of
MDD, i.e. a clinical interview. Several studies have attempted this
and identified the BDI,25 the Centre for Epidemiological Studies
Depression Scale (CES-D26) and the Patient health questionaire
( PHQ-927) as valid instruments for this purpose.
Beck Depression Inventory (BDI)
BDI identifies people with comorbid MDD at a cut-off score ≥ 16 for
the entire 21-item measure.25
CES-D
McHale et al. found the CES-D to be superior to three other
questionnaires, namely the Hospital Anxiety and Depression scale
( HADS), the Silverstone Concise Assessment for Depression (SCAD)
and the Depression in the Medically Ill questionaire (DMI), in
detecting MDD in persons with diabetes. 26
Table 1. Main DSM-IV criteria for major depressive disorder
At least one of the two following symptoms for two weeks, nearly
every day:
1) Depressed mood
2) Loss of interest or pleasure
Furthermore, at least four of the following extra symptoms:
3) Weight loss or decrease or increase in appetite
4) Insomnia or hypersomnia
5) Psychomotor agitation or retardation
6) Fatigue or loss of energy
7) Feelings of worthlessness or guilt
8) Diminished ability to think or concentrate
9) Recurrent thoughts of death, recurrent suicidal ideation without a specific
plan or a suicide attempt or a specific plan for committing suicide