More treatment but no less depression: The treatment-prevalence paradox

Summary & key facts

Since the 1980s, treatments for depression have gotten better and a lot more people can get them. But the proportion of people in the general population with depression has not gone down. The researchers looked at seven ideas to explain this paradox. They found little support for the idea that better treatment was hidden by more people being misdiagnosed or by a true rise in new cases. Instead, the best evidence shows that published studies make treatments look more effective than they really are, treatments work less well outside of controlled studies, and treatment helps people with single or short episodes more than it helps those with long-lasting or recurring depression. There is almost

Key facts:

• Treatments for depression have improved and become much more available since the 1980s, but the overall number of people with depression in the general population has not fallen.
• The researchers considered seven possible explanations for this mismatch between more treatment and steady prevalence.
• Two explanations would still mean treatments worked: that doctors are now mislabeling normal distress as depression, or that new cases of depression have really increased. The authors found little evidence for either of those ideas.
• There is strong evidence that published studies overstate how well depression treatments work, both in the short term and the long term.
• Depression treatments are noticeably less effective when used in everyday real-world settings than they are in controlled research studies.
• How much treatment reduces depression in the population depends a lot on the type of depression. People with long-lasting or recurring depression benefit less at the population level than people with single or short episodes.
• Very little research has looked at whether current treatments sometimes cause harm, so we don’t know enough about possible negative effects and this needs more study.

Abstract

Treatments for depression have improved, and their availability has markedly increased since the 1980s. Mysteriously the general population prevalence of depression has not decreased. This "treatment-prevalence paradox" (TPP) raises fundamental questions about the diagnosis and treatment of depression. We propose and evaluate seven explanations for the TPP. First, two explanations assume that improved and more widely available treatments have reduced prevalence, but that the reduction has been offset by an increase in: 1) misdiagnosing distress as depression, yielding more "false positive" diagnoses; or 2) an actual increase in depression incidence. Second, the remaining five explanations assume prevalence has not decreased, but suggest that: 3) treatments are less efficacious and 4) less enduring than the literature suggests; 5) trial efficacy doesn't generalize to real-world settings; 6) population-level treatment impact differs for chronic-recurrent versus non-recurrent cases; and 7) treatments have some iatrogenic consequences. Any of these seven explanations could undermine treatment impact on prevalence, thereby helping to explain the TPP. Our analysis reveals that there is little evidence that incidence or prevalence have increased as a result of error or fact (Explanations 1 and 2), and strong evidence that (a) the published literature overestimates short- and long-term treatment efficacy, (b) treatments are considerably less effective as deployed in "real world" settings, and (c) treatment impact differs substantially for chronic-recurrent cases relative to non-recurrent cases. Collectively, these a-c explanations likely account for most of the TPP. Lastly, little research exists on iatrogenic effects of current treatments (Explanation 7), but further exploration is critical.

Topics

Mental Health Research Topics Mental Health Treatment and Access Treatment of Major Depression

Categories

Experimental and Cognitive Psychology Psychology Social Sciences

Tags

Clinical psychology Depression (economics) Distress Economics Environmental health Incidence (geometry) Macroeconomics Medicine Optics Physics Population Psychiatry Psychology

Conditions & symptoms

Depression Lack of energy or motivation Poor sleep Sadness or low mood