What is mental illness?

Published on October 6, 2012

When you hear that someone has been diagnosed with a ‘mental illness’ — what enters your mind? 

Is it that the person is perhaps psychotic?  Delusional?  Dangerous?  Would it change your opinion of your babysitter?  Your new love interest? Since the phrase mental illness is often used as a blanket term to describe everything from anxiety to psychosis, it often difficult to discern what is actually meant.

defining mental illness

Citing recent public policy debates in Australia, for instance, a paper recently published in the The Australian and New Zealand Journal of Psychiatry points out “those advocating for more funding often cite statistics on the prevalence of mental illness in the community as well as the levels of unmet need, for example, a commonly-cited statistic in these recent debates is that one in five adults, or one in four young people, suffers from mental illness.”1

Discussions like this beg the question — what  exactly is mental illness?  The American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders seems a likely resource to answer the question.  To that point, the paper authors are right in mentioning “with the imminent release of DSM-5 there have been fierce debates about the possible inclusion of a number of new conditions.”

The new DSM-5, due to be released in March of 2013 will show a greater dependence upon the flood of neuroanatomical, biochemical and imaging discoveries rushing out of laboratories worldwide. One important development is an increasingly biochemically- nuanced interpretation of mental illness. 

Take for example the now recognized connection between hormone levels and mental illness.  Further, correlations have been identified between several major illnesses such as cancer and heart disease with mental illness.  Complicating things even more is the increasing tendency to view mental illness from a bio-psycho-social perspective that introduces an almost endless number of variables.

Because of the quickly changing landscape of mental healthmental illness diagnosis, the authors appear prudent in their insistence that “those advocating for increased funding for services and research should clearly define what they mean by the terms 'mental illness' and 'unmet need' or else refer to specific disorders.”  The suggestion of specificity is as important for the newly included DSM-5 illnesses as it is for those that will be deleted.  

Attenuated Psychosis Syndrome is an example of a diagnosis that has been quite controversial for some time and the American Psychiatric Association has decided to exclude it from the forthcoming DSM edition.  Originally theorized to identify potentially psychotic persons at an early age, the criteria depended to heavily of the symptom of hallucinations.  Consequently, since a significant proportion of those who suffer hallucinations do not meet the clinical threshold established for mental illness, patients were over-diagnosed with the syndrome.

Still discussing the advantage of being more specific in with terms, I agree with the authors’ assertion that “the issue of public understanding of the phrase “mental illness” also has implications for stigma reduction campaigns.”  However, I am not completely supportive of their statement, “Given that the public largely associates the term 'mental illness' with more severe disorders, it is likely that 'mental illness' is acceptable for anti-stigma campaigns that focus on these disorders, while campaigns that aim to de-stigmatize high prevalence disorders should use specific labels.”

My fear is that the public might erroneously conclude a correlation between illness severity and media attention.  For example, if they assume a direct correlation, that only the most severe conditions are mentioned by name in campaigns, it would have the effect of reinforcing their uninformed fears.  Even the converse supposition—less media coverage means less disease severity—would be distorted.

The researchers also expend effort to “highlight the risks of broadening public conception of the label “mental illness” to include lower prevalence disorders, as this may risk spreading the stigmatizing attitudes linked to severe illnesses to disorders such as anxiety or depression.”  I must differ on this strategy also.  My concern is that “prevalence” is largely a function of the sensitivity and specificity of our technology.  A condition might increase in statistical prevalence because of improved detection, not increased incidence.  Thus, given the increasing ability of science to detect abnormalities via biochemical, imaging and molecular techniques, we can expect several diseases to become “more prevalent” in the coming years.

More to the point of the author’s claim that we should reserve the term “mental illness” for the higher prevalence conditions, I believe that as our detection increases, we will undoubtedly be able to identify diseases at earlier stages, but this does not mean that reduce the prevalence should reduce our attention. Take for example cervical cancer.  Since the introduction of the Papanicolaou test (Pap smear) the incidence of cervical cancer has been reduced by up to 80% in some populations2 , yet today it is still the second most common cancer in women worldwide3.

In general, I support the authors’ premise. Once we identify the mental illness, we can identify the therapy, which goes a great way to enabling the accurate planning of relevant federal, state and municipal budgets.

If you are connected to this topic through personal experience or otherwise, let us know your thoughts.  Until next time…KEEP THINKING!



1 Jorm, Anthony F.; Reavley, Nicola J. Public confusion caused by differing understandings of the term ‘mental illness’. Australian and New Zealand Journal of Psychiatry, Vol 46(5), May 2012, 397-399.

2 M. Arbyn; et al. (2010). "European Guidelines for Quality Assurance in Cervical Cancer Screening. Second Edition—Summary Document". Annals of Oncology 21 (3): 448–458. doi:10.1093/annonc/mdp471. PMC 2826099. PMID 20176693

3 Armstrong EP (April 2010). "Prophylaxis of Cervical Cancer and Related Cervical Disease: A Review of the Cost-Effectiveness of Vaccination Against Oncogenic HPV Types". Journal of Managed Care Pharmacy 16 (3): 217–30. PMID 20331326.


Written by:

Tony Brown

Tony Brown is a former U.S. Army (Reserve) Medical Officer, and currently completing his studies as an M.D./PhD/MBA candidate, with a research thesis titled, “Pharmacology and the Neurological Correlates of Consciousness.”

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