Mental illnesses are currently diagnosed based on behavior and symptoms; there is currently no chemical test to determine mental illness.  The determination of a mental illness is made based on the diagnostic criteria set forth in the Diagnostic and Statistical Manual of Mental Disorders, which is now in its fifth edition (DSM-V).

The National Institute of Mental Illness (NIMH) at https://www.nimh.nih.gov/health/statistics/mental-illness explains that “Nearly one in five U.S. adults live with a mental illness (52.9 million in 2020). Mental illnesses include many different conditions that vary in degree of severity, ranging from mild to moderate to severe. Two broad categories can be used to describe these conditions: Any Mental Illness (AMI) and Serious Mental Illness (SMI).   AMI encompasses all recognized mental illnesses. SMI is a smaller and more severe subset of AMI.” 

The NIMH distinguishes them in this way:

    “Any mental illness (AMI) is defined as a mental, behavioral, or emotional disorder. AMI can vary in impact, ranging from no impairment to mild, moderate, and even severe impairment (e.g., individuals with serious mental illness as defined below).” 

     “Serious mental illness (SMI) is defined as a mental, behavioral, or emotional disorder resulting in serious functional impairment, which substantially interferes with or limits one or more major life activities. The burden of mental illnesses is particularly concentrated among those who experience disability due to SMI.”  

The problem is that most people don’t understand the differences, and particularly how SMI is unique.  Decision-makers too often blur the line between SMI and AMI, often because it is easier to talk about, prevent and treat milder forms of mental illness with publicly popular “mental health” programs emphasizing reducing stress, practicing mindfulness, setting up support groups in schools to ease anxiety among students, and similarly valuable and low-hanging therapeutic fruit.

                                                                                          SERIOUS MENTAL ILLNESS SHOULD BE RECLASSIFIED AS A SERIOUS BRAIN DISORDER.

However, SMI is entirely different, in that it involved psychosis and needs intense, specialized treatment. SMI involves actual disease of the brain and is more than a behavioral or emotional disorder.  Disorders like schizophrenia, schizo-affective disorder, severe depression, and severe bipolar disorder, where psychosis is a symptom are brain-based and medical in nature.  FASMI is part of a movement, led by the National Shattering Silence Coalition (NSSC), dedicated to the reclassification of serious mental illnesses as serious brain disorders (SBDs) and the inclusion of SBDs in the National Neurological Conditions Surveillance System.  See the NSSC’s Points of Unity at https://docs.google.com/document/d/1BTWvJbbjBOq5HWeZolkjHHyLLSFgxn3vcuu9vY-B-K0/edit. This would move the treatment of SMI under the umbrella of neurological and medical conditions which are handled differently (and distinguished from milder mental illnesses in terms of insurance coverage, placement in hospitals/facilities, etc.). 

As the Mental Illness Policy Organization puts it: “US mental health spending and mental health non-profits focus almost exclusively on people who do not have serious mental illness, rather than those who do. This is the single major problem with the US mental health system. More money will not help the seriously mentally ill if it is not allocated to the seriously ill. Prioritization is needed. / We should replace mission creep with mission control and return the mental health system to one that gets treatment to those with the most serious mental illness rather than one that works to improve the mental health of all others.”  https://mentalillnesspolicy.org/serious-mental-illness-not

Read more in this blog by Katie Dale here.  

Also see:

https://www.nimh.nih.gov/health/statistics/mental-illness

https://smiadviser.org/about/serious-mental-illness

https://www.samhsa.gov/serious-mental-illness

https://guildservices.org/blog/what-is-a-serious-mental-illness/ 

https://www.ncbi.nlm.nih.gov/books/NBK20369/

Mental Health vs. Mental Illness:  https://healingmindsnola.org/video-archives/

See also the Schizophrenia and Psychosis Action Alliance – https://sczaction.org/ – which leads a movement for systemic change  including  the principle that schizophrenia is a treatable brain disease and should be treated like any other neurological illness.