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In 1996, Australia's National Health Priority Area initiative identified mental health as a priority area, and, currently, a draft Depression Action Plan has been released for community consideration. This year, a National Depression Initiative has been set up, with Jeff Kennett, the former Premier of Victoria, as chairman. Both these processes recognise the magnitude of the problem and the need for management strategies, while indirectly contributing powerfully to destigmatisation.

In this issue of the Journal, McManus and colleagues ⁵ report a tripling in antidepressant prescriptions in the 1990s in Australia and most other developed countries, and illustrate the "diffusion of an innovation", clearly in line with the noted explosion of information about depression.

In contrast, when antidepressants were discovered in the late 1950s, companies were reluctant to release them commercially, as the market was judged too small.⁶ Depression then was a disorder virtually confined to asylums, and only later formally defined. The American Psychiatric Association's DSM-III manual introduced "major depression" in 1980, an entity then quantified as dominating psychiatric practice, and highly prevalent in general practice and the community. Minor depressive disorders were defined and, more recently, entities such as "sub-clinical depression" and "sub-syndromal depression" have appeared. These have been shown to be associated with considerable disability and amenable to intervention, and thus postulated as disorders.⁷ If such trends continue, depression will soon be destigmatised by virtue of a depressive subtype for everyone!

Such extensions raise predictable questions. Where should the line be drawn in determining "caseness"? As a consequence of stigma or other factors, were we previously minimising, misinterpreting and missing depression? Or are we now excessively "pathologising" aspects of human distress?

When psychiatry emerged from its quaintness in the 1960s by adopting a dominant biological model, the "barons" advocating the new Zeitgeist joined with the pharmaceutical industry to promote depression as a medical disorder, and a singularly effective treatment modality -- antidepressant drugs. New drugs were then marketed to redress both the clinical and profit limitations of the old antidepressants. But let's not be critical of the pharmaceutical industry for doing its job, and instead question whether its advertised message should be echoed by professionals. In essence, the message has three components:

• depression is a distinct medical condition, best treated by antidepressant drugs;

• the new drugs are as effective as their predecessors; and

• the new drugs have few side effects, are well tolerated and safe.

Each of these issues is worth examining.

• First, is depression a distinct medical condition?⁸ Not so. Depression can be a normal mood state -- brief, self-remitting, and ubiquitous. It also exists as a disease, now commonly termed "melancholia", having negligible spontaneous and placebo response rates, with strong biological origins mandating physical treatments.

  More problematic is the group of disorders once termed neurotic or reactive depression, representing the heterogeneous residue left after excluding the melancholic disorders. It has no distinct or defining clinical features, and high placebo and spontaneous remission rates. This group is better viewed as comprising "spectrum disorders", whereby people with certain temperament styles (eg, anxious worrying, introverted, volatile, obsessional) are disposed to develop depression as a consequence of their temperament style when facing certain stressors. As these temperament styles reflect extremes of normal personality dimensions, the non-melancholic conditions are themselves dimensional, allowing disorder status and need for intervention to be arbitrarily defined, and, as detailed by McManus and colleagues,⁵ providing the growth arena for the new antidepressant drugs.

• Second, how effective are our current antidepressant drugs? For psychotic melancholia,⁹ psychotherapies have no primary role. An antidepressant drug alone will benefit only a quarter, an antipsychotic drug alone a third, while their combination (as with electroconvulsive therapy) will benefit 80% -- distinctly differing levels of effectiveness.⁹ For non-psychotic depression, the dissonance between drug efficacy data and clinical observation is perturbing. A recent review considered 150 efficacy studies involving 160 000 patients with major depression, concluding that the newer and older antidepressants were equally efficacious.¹⁰ However, clinical effectiveness data suggest that the older antidepressants (ie, the tricyclics and the irreversible monoamine oxidase inhibitors) are more effective for melancholia, while, for non-melancholic depression, the newer antidepressants appear (overall) to be as effective.¹¹ Thus, by "homogenising" depression as an entity, specificity of drug action is submerged, assisting marginalisation of the older (low-profit) antidepressants.

• Thirdly, how safe, acceptable and tolerable are the newer antidepressants? Drop-out rates due to adverse effects only slightly favour them,¹² with an appreciable percentage of patients experiencing side effects, which range from alarming (serotonergic reactions on commencement, discontinuation reactions, drug-drug interactions) to inconvenient. Perhaps the most-conceded benefits are their clear-cut cardiac advantages and their non-lethality when taken in overdose.

But how truly beneficial are the newer antidepressants? The selective serotonin reuptake inhibitors (SSRIs) are generally considered to be safe and well tolerated. Rarely conceded, and often unrecognised, is that they have the potential to modify several personality styles that dispose to non-melancholic depression (eg, anxious worrying).¹³ This gives SSRIs a powerful prophylactic role, strongly underpinning patient and prescriber acceptability.

Their anti-worry role is neither trivial nor worthy of inciting "cosmetic psychopharmacology" claims. For many who develop non-melancholic depression, taking an SSRI is associated with a normalising of worry and a lessening of both anxiety and irritability. Real-world problems remain, but are viewed and addressed more normally, and resilience to stressful events is increased.

Such properties of the SSRIs are noteworthy and, in light of the prevalence of "at-risk" temperament styles (let alone depression), offer a strong utilitarian argument for the SSRIs and some other new antidepressant classes. Regrettably, current alternatives for managing non-melancholic depression are few, when practice and training issues are considered along with efficiency and effectiveness. Many chant the utility of cognitive behaviour therapy, but we need to be assured that advocacy is not merely "non-drug" voting. Although cognitive behaviour therapy (CBT) has high treatment credibility, King, after reviewing several major trials, argues that CBT has little treatment specificity for depression, is highly demanding of time and requires well-trained therapists.¹⁴ The high non-specific remission rate attests to the importance of CBT having non-specific therapeutic ingredients, which, together with the high spontaneous remission rate, argue for wise counselling for those with non-melancholic disorders.

Finally, should we worry about increased prescribing? Alone, the growth of any effective treatment should be welcomed. But the new Zeitgeist may encourage doctors to reach for a prescription pad at the first suggestion of "depression", welcoming the time and cost efficiency. Such a narrow approach may meet the doctor's practice needs, but is rarely welcomed by patients. Mental health literacy data reveal that the public rates antidepressant medication poorly and as addictive, issues which need redressing.¹⁵ Any prescription of an antidepressant should be one component of a pluralistic approach, with the prescriber appreciating the patient's world and predicaments, and providing counselling to assist the patient to come to terms with depression's manifestations, consequences and "meanings".

Gordon B Parker
Professor, School of Psychiatry, University of New South Wales
Research Director, Mood Disorders Unit, Prince of Wales Hospital, Sydney, NSW

1. World Health Organization and the World Bank. The Global Burden of Disease: summary. Cambridge, Mass: The Harvard School of Public Health, Harvard University Press, 1996.
2. Mathers CD, Vos ET, Stevenson CE, et al. The Australian Burden of Disease Study: measuring the loss of health from diseases, injuries and risk factors. Med J Aust 2000; 172: 592-596.
3. Andrews G, Hall W, Teeson M, et al. National Survey of Mental Health and Wellbeing. Report 2. The Mental Health of Australians. Canberra: Mental Health Branch, Department of Health and Aged Care, 1999.
4. Kessler RC, McGonagle KA, Zhao S, et al. Lifetime and 12-month prevalence of DSM-III-R psychiatric disorders in the United States. Arch Gen Psychiatry 1994; 51: 8-19.
5. McManus P, Mant A, Mitchell PB, et al. Recent trends in the use of antidepressants in Australia, 1990-1998. Med J Aust 2000; 173: 458-461.
6. Healy D. The antidepressant era. Cambridge, Mass: Harvard University Press, 1997.
7. Judd LL, Paulus MP, Wells KB, et al. Socioeconomic burden of subsyndromal depressive symptoms and major depression in a sample of the general population. Am J Psychiatry 1996; 153: 1411-1417.
8. Parker G. Classifying depression: should paradigms lost be regained? Am J Psychiatry 2000; 157: 1204-1211.
9. Parker G, Roy K, Hadzi-Pavlovic D, et al. Psychotic (delusional) depression: a meta-analysis of physical treatments. J Affect Dis 1992; 24: 17-24.
10. Anderson IM. Selective serotonin reuptake inhibitors versus tricyclic antidepressants: a meta-analysis of efficacy and tolerability. J Affect Dis 2000; 58: 19-36.
11. Parker G, Mitchell O, Wilhelm K, et al. Are the newer antidepressant drugs as effective as established physical treatments? Results from an Australasian clinical panel review. Aust N Z J Psychiatry 1999; 33: 874-881.
12. Mitchell PB. The new antidepressants -- are they worth the cost? Aust Prescriber 1995; 4: 82-84.
13. Andrews W, Parker G, Barret E. The SSRI antidepressants: defining their "other" possible properties. J Affect Dis 1998; 49: 141-144.
14. King R. Evidence-based practice: where is the evidence? The case of cognitive behaviour therapy and depression. Aust Psychol 1998; 33: 83-88.
15. Jorm AF, Korten AE, Jacomb PA et al. Mental health literacy: a survey of the public's ability to recognise mental disorders and their beliefs about the effectiveness of treatment. Med J Aust 1997; 166: 182-186.

©MJA 2000
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