Is Depression Overdiagnosed?

About 121 million people are affected by depression worldwide, according to the World Health Organization, and rates of diagnosis have increased significantly in recent years. But are too many people now being diagnosed with depression? Gordon Parker, MB BS, MD, PhD, DSc, and Ian Hickie, MD, debated whether the diagnostic criteria for depression are too broad, leading to overdiagnosis in the general population, in editorials published in the August 18 BMJ and shared their opinions with NeuroPsychiatry Reviews.

DEPRESSION IS OVERDIAGNOSED

Dr. Parker, Executive Director of the Black Dog Institute at the Prince of Wales Hospital in Sydney, believes that lowering the threshold for depression diagnosis risks leading to the treatment of normal emotional states as illness. “Everyone gets depressed,” Dr. Parker told NeuroPsychiatry Reviews, “and we can certainly destigmatize ‘depression’ as it ranges from the severe disease states even through to the normal mood states—by information and by suggesting appropriate strategies. The problem emerges if the overdiagnosis leads to inappropriate [treatment] or overtreatment.” Dr. Parker is also a Scientia Professor in the School of Psychiatry at the University of New South Wales in Sydney.

In the 1980 revision of its diagnostic manual, the DSM-III, the American Psychiatric Association exchanged a descriptive definition of depressive disorders for a criterion-based dimensional system, which categorized the disease into major and minor disorders, noted Dr. Parker. “Although its descriptive profile prioritized melancholic features (such as serious psychomotor disturbance or anergia), DSM-III’s operational criteria were set ‘at the lowest order of inference,’” he stated. A patient who reported dysphoric mood for two weeks—including feeling sad, blue, or down in the dumps—and experienced appetite change, sleep disturbance, drop in libido, and fatigue could now obtain medical insurance coverage for depression. Minor depressive disorder, or dysthymia, requires “even fewer and less substantive symptoms such as crying, decreased productivity, and feeling sorry for yourself,” he added. Dr. Parker also asserted that easing the threshold for diagnosis has blunted the clarification of causes and treatment specificity, as no reproducible consistent pattern of neurobiologic changes or treatment responses has been observed in major depression.

DEPRESSION IS NOT OVERDIAGNOSED

In contrast, some clinicians believe that the melancholic definition of depression requires patients to meet an extreme form of illness, and reversion to this attitude would deny treatment to many who still need help. “Its main purpose is to restrict treatment to the most severe cases only,” said Dr. Hickie, Executive Director of the Brain and Mind Research Institute at the University of Sydney, in an interview with NeuroPsychiatry Reviews. “This approach attracts the least criticism of the practitioner but also yields the least benefit for the community at large.” The danger, he said, is that most suicides occur in persons with only moderately severe depression.

Dr. Hickie views the current diagnostic criteria for depression, and the subsequent increased rate of diagnosis, as the cause and effect of a reduced stigma against the symptoms of disease. “We have at last abandoned the demeaning labels of stress, nervous breakdown, and adolescent angst,” he said. The risks of not getting treatment are better understood as well. As for attaching a medical diagnosis to a normal emotional state, “Normal sadness does not often present for medical help,” said Dr. Hickie. And when it does, “most doctors can now differentiate normal sadness and distress from the more severe clinical conditions.”

OPTIMIZING TREATMENT FOR DEPRESSION

Drs. Hickie and Parker believe that some patients would benefit from therapeutic interventions other than antidepressant treatment. “We should concentrate on providing effective treatments (not just medicines) to as many people as are likely to receive great benefits,” said Dr. Hickie. “Suicide rates remain unacceptably high …, and the most effective method for reduction is active treatment of depression.” He also advised extra caution when treating patients younger than 18. “Community concern should focus on whether drugs or psychological approaches are given as first-line treatments,” he said, though he did note that the overall response in those younger patients with more severe disorders is encouraging.

In Dr. Parker’s view, patients with melancholia-rooted depression could be helped by medications, but other causes may need to be treated with other forms of therapy. “People with melancholia have a 60% to 70% chance of responding to an antidepressant, as against a 10% response to placebo,” he said. “As you move from such a biological disorder to the nonmelancholic conditions, the differential gradient for antidepressant efficacy attenuates.” Therefore, when patients with a nonmelancholic form of depression are diagnosed and prescribed such medications, their hopes for improvement are raised but may not come to fruition. Instead, Dr. Parker recommended treatment of the true cause of a patient’s nonmelancholic depression. This might involve counseling if the cause is social or cognitive behavior therapy if the cause is psychological.

“In essence, we are arguing a more commonsense approach that occurs across the rest of medicine but does not appear to be applied widely in managing the mood disorders,” concluded Dr. Parker.           

—Jessica Dziedzic

Suggested Reading
Hickie I. Is depression overdiagnosed? No. BMJ. 2007;335 (7615):329.
Parker G. Is depression overdiagnosed? Yes. BMJ. 2007;335 (7615):328.

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