Should depression be managed as a chronic disease?

In 1970 L G Kiloh and I finished recruiting patients for a prospective
study of depression in admissions to a new general hospital psychiatric
unit. When we published the 15 year follow up we discovered that our
patients had not done at all well[1].

Only (20%) a fifth recovered and remained continuously well, (60%) three
fifths recovered but had further episodes, and (20%) a fifth either
committed suicide or were always incapacitated. An English 15 year follow
up study published at the same time showed identical results [2].

The obvious conclusion was that people admitted to hospital in the 1970s
with a depressive illness did not have a good prognosis. In retrospect, I
ask why more of those who relapsed did not return to us for treatment.

These results are not atypical. A detailed 12 year follow up in US
specialist care showed that patients on average had symptoms in 59% of
weeks and met full criteria for a depressive episode in 15% of weeks [3].

Depression seems to be a chronic recurring disorder, seldom well managed if
one simply waits for the patient to initiate further consultations.


Summary points

1. The burden of depression is not being reduced.

2. The episodic nature of depression and the acute response to treatment
means that episodes seem easy to treat.

3. They can be if patients comply with drug and cognitive therapy regimens.

4. The main problem is the next recurrence, if patients do not to come for
treatment at all.

5. To reduce the burden of depression, we argue for a chronic disease
management model.

6. We should manage depression proactively to ensure long term compliance
with treatment.


Methods

I identified references to remission and relapse of depression during the
writing up of the Australian national mental health survey. References to
long term prognosis came from my earlier work. A conference question, "What
is the clinical implication of your findings?" led me to the Wagner model
of chronic disease management.


Depression is treatable

In 1990, depression was the 4th most important determinant of the global
burden of disease and the largest determinant of disability in the world [4].

The burden of depression is not being reduced, partly because too many
people do not seek treatment and partly because efficacious treatments are
not used effectively [5].

Neither good education of providers [6,7], nor increased prescribing of
antidepressants [8], seems to reduce the burden. This has puzzled informed
observers [9].

There is good evidence from controlled trials of the efficacy of short term
treatment [10], exactly as the drug advertisements suggest.

Four types of antidepressant drugs, cognitive behaviour and interpersonal
therapy, and electroconvulsive therapy have all been shown to produce
benefits of 0.5 to 1.0 standard deviation over the response to placebo.

However, most trials cover only short periods, just long enough to
establish the acute response to treatment. The longest comparison trial of
maintenance treatment is only three years [11].

The change in the placebo control group itself is considerable, greater
than the additional improvement due to any specific treatment and probably
the largest in any mental disorder [12]. This is in part because of the
frequency of spontaneous remission and in part because of the sensitivity
of depressed patients to the encouraging effects of being in treatment [13].

These two factors, a large response to acute treatment and the short
duration of many episodes without treatment, lead to the idea that
depression should not be a disease of great burden. This optimism is ill
founded.


Remission and relapse are common

Just what is the likelihood of spontaneous remission? Two wave prospective
surveys are necessary to determine the duration of depressive episodes in
the community.

There are two such surveys [14,15], and both show that the median duration
of depressive episodes was 8 weeks (mean 16 weeks), with only 5% of people
not recovered at 1 year.

In the Australian mental health survey less than half the people with
depressive episodes some time during the year had symptoms that met the
criteria for depression during the month of the interview.

Depression is a disorder that remits [5, 16]. Depression also recurs.

The people in the Australian survey who met criteria for depression during
the previous year dated the onset of their first episode an average of 5.4
years earlier (range 1-54 years).

Nearly half (44%) reported a previous episode within 12 months of their
latest episode, and 39% had met ICD-10 criteria (international
classification of diseases, 10th revision) for a full remission between the
2 episodes.

The US national comorbidity survey showed that (75%) three quarters of
people aged 15-54 years who had ever met criteria for depression had had
more than 1 episode [17]. Their mean age was 34, and they reported an
average of 11 prior episodes, each lasting from two to 69 weeks.

In our twin study people with a lifetime history of depression reported an
average of 8 episodes in the 11 years since their first episode [18]. The
duration of episodes was similar to that reported in the US survey.

Depression in the community remits and recurs, and the frequency of
remission may lead clinicians to underestimate the probability of relapse.


Managing depression as a chronic disease

A model of practice in which patients seek help only when they deem it
necessary is not appropriate for an episodic but lifelong condition that
affects hope and volition, reduces compliance, and predisposes to suicide.

Would it be better managed by a chronic disease management model like that
used for diabetes?

But even that is difficult. Consider a person recovering after 12 months of
despair, loss of energy, weight loss, and insomnia. At the point of
recovery, few doctors would want to broach the issue of chronicity, and few
patients (we used to think) would want to hear about it.

Yet if the diagnosis was diabetes there would be instant discussion of the
chronic nature of the disorder and the steps needed to manage it.

Wagner et al described a model for the management of chronic disease and
gave examples of the changes to usual practice needed [19]. Katon et al
have applied this model to depression to prevent chronicity and relapse,
the principal determinants of burden [20].

There seem to be four components:

1. Practice reorganisation: Establish a register of cases and proactively
organise consultations, seeing people frequently during an acute phase and
less frequently during remissions.

2. Patient education: Use booklets, videotapes, and family consultations to
educate patients and their families about the signs and symptoms of
depression, about antidepressant drugs, about psychological approaches to
aid recovery, and about early warning signs that herald relapse.

3. Expert systems: Have clinical practice guidelines for diagnosis and for
management of acute episodes, maintenance, and relapse. Establish criteria
for specialist consultation and for sharing care with psychologists and
nurses.

4. Computer support: Produce a package that records treatment and outcome
measures and flags when progress is not as expected.


Does this work?

Enhanced treatment of acute episodes in accord with the Wagner criteria
produced better outcomes in depressive patients treated in primary care,
but 1 year later the outcomes were no better than with usual care [21]. The
authors concluded that continued enhanced care was required, which is not
surprising given the chronic nature of the disorder.

Is this feasible?

Quite apart from the burden of disease, persistence of chronic conditions
produces direct treatment costs. People with depression generate twice the
healthcare costs of other primary care attenders, high even after the
impact of comorbid conditions is controlled [22].

Proactive care costs more than usual care, but the cost per patient
successfully treated is lower, and the cost effectiveness higher, than for
patients given usual care [23].

Proactive care for people with subsyndromal depression was not found to be
cost effective, which means that the cost profiles of strategies for
maintenance and prevention of relapse need to be improved [24], perhaps by
consultations by ancillary staff or by interactive voice response
telephony, and compared with the gains possible from use of funds for other
conditions.


Is being so proactive fair?

Managing depression as a chronic disorder raises 3 questions for which
there are no conclusive answers:

1. How do patients respond when told their disease is likely to recur?

Many doctors are concerned that telling people the true prognosis will
cause their depression to worsen. This belief seems to be widely held and
certainly needs research. At this centre we have begun to be more honest
with people about their prognosis. This takes time, but we have had no
complaints and compliance has improved. "This is the first time I have
understood the importance of treatment," is the usual response we get from
patients. People have a right to the truth.

2. How do you identify the people likely to relapse?

About (50%) half of a community sample of people who have recovered from
depression will relapse within 1 year, and most will relapse within 2
years. Clinical practice guidelines suggest that maintenance treatment be
deferred until the 2nd or 3rd episode [25,26]. People seldom seek help for
their 1st attack of depression, only for subsequent attacks, although good
interviewing and good rapport may be required to elucidate the earlier
episodes. The 1st treated episode is often the 3rd or 4th actual episode.
Again research is needed.

3. How do we know that a proactive chronic disease model is better than the
present "laissez-faire" model?

We, like the Seattle group [20], have adopted a proactive approach to
management of current illness. When people do not take their drugs,
implement their pleasant event activities, use problem solving, or attend
for appointments we ask why. Whether such proactive care works in the
longer term is simply unknown, and research is needed. However, we think
anything is better than leaving patients to languish at home, too dysphoric
and anergic to seek help.

Depression and diabetes are alike in burden, and both have chronic courses
marked by periods without symptoms and by occasional emergencies.

The UK prospective diabetes study showed the effectiveness of intensive
follow up in preventing long term complications in diabetic patients [27].

There has been no equivalent study in depression, and, given the promise of
the work by the Seattle group, the time is ripe for such a long term
prospective study.

We must encourage research into efficient strategies for long term
treatment and prevention of relapse in depression. After all, it is the
largest single cause of disability in the world.


References

1.  Br J Psychiatry 1988; 153: 752-757
2.  Br J Psychiatry 1988; 153: 741-751
3.  Arch Gen Psychiatry 1998; 55: 694-700
4.  Lancet 1997; 349: 1498-1504
5.  Bull World Health Organ 2000; 78: 446-454
6.  Br J Gen Pract 1999; 49: 99-102
7.  Lancet 2000; 355: 185-191
8.  Clin Drug Invest 1998; 16: 453-462
9.  Br J Gen Pract 1999; 49: 91-92
10. Oxford: Oxford University Press, 1998
11. Arch Gen Psychiatry 1990; 47: 1093-1099
12. Br J Psychiatry (in press)
13. Science 1999; 284: 238-240
14. Psychol Med 1997; 27: 107-117
15. J Abnorm Psychol 1992; 101: 277-286
16. Br J Psychiatry (in press)
17. J Affective Disord 1997; 45: 19-30
18. J Affective Disord 1990; 19: 23-29
19. Millbank Q 1996; 74: 511-543
20. Gen Hosp Psychiatry 1997; 19: 169-178
21. Am J Psychiatry 1999; 156: 643-645
22. Arch Gen Psychiatry 1995; 52: 850-856
23. Pychosom Med 1998; 60: 143-149
24. JAMA 1995; 273: 51-58
25. AHCPR Publication No 93-0551
26. American Psychiatric Association. 1996
27. Lancet 1998; 352: 823-833


Gavin Andrews,
professor of psychiatry.
WHO Collaborating Centre for Mental Health and, School of Psychiatry,
UNSW at St Vincent's Hospital,
299 Forbes Street, Sydney, 2010, Australia
[log in to unmask]
(Accepted 25 October 2000)
BMJ 2001;322:419-421 ( 17 February )
http://bmj.com/cgi/content/full/322/7283/419

janet paterson, an akinetic rigid subtype parkie
53 now / 44 dx cd / 43 onset cd / 41 dx pd / 37 onset pd
TEL: 613 256 8340 SMAIL: PO Box 171 Almonte Ontario K0A 1A0 Canada
EMAIL: [log in to unmask] URL: http://www.geocities.com/janet313/