Severe mental illness (SMI): another muddled idea from psychiatry

  • February 22, 2021

Not all psychiatrists recognize this explicitly, but there is an assumption in psychiatric practice that mental disorders are arranged in a hierarchy with those at the top being more serious than those lower down. The hierarchy has often been represented in a pyramid introduced some 50 years ago by two academics working in Edinburgh. 

At the bottom of the pyramid are states of personal distress (in the original account called dysthymic states) characterised by symptoms such as anxiety, irritability, low mood and non-specific physical symptoms. In the so-called neurotic disorders the symptoms are still recognizable as part of distress, but one or more of them seems to have taken on a life of its own – out of proportion to other symptoms of distress and perhaps distorted or expressed in an unusual way. Higher up the pyramid are delusional (psychotic) states, characterised by the emergence of symptoms that are not part of mainstream experience – like holding delusional beliefs or hearing voices. At the very top are extreme states where mental life is so disrupted that a stable sense of self is difficult to find.

This arrangement represents a hierarchy in another sense, that of progressive deterioration in the organisation of mental function so that those higher up can have symptoms from any of the states lower down in the hierarchy without their diagnosis needing to change, but not vice versa.

The hierarchy is nodded at in the arrangement of the two standard diagnostic manuals – current editions DSM5 and ICD11 – in which schizophrenia and related disorders appear before severe mood disorders and then move on to the neurotic disorders.

Over time, perhaps especially in the UK, it has become common practice to talk about severe mental illness, initialised (always a bad sign) as SMI, and SMI has come to mean “any psychotic disorder”. This was never a good idea. In many branches of medicine the diagnosed disorder can be a pointer to severity but the coupling is not so strong that diagnosis can be taken as a severity statement. Some diabetes is more severe than some cancer and some COPD is more severe than some leukaemia.

So, what do we mean by severity? The answer takes us into matters that are more important to patients than the classificatory ordering of symptom states – for example impact on life expectancy, quality of life, ability to function physically (impairment or handicap) or socially (participation) come into the frame.

Is there a tension between these two ways of looking at severity? The UK government’s vaccination policy in the COVID pandemic certainly suggests some lack of clarity about what severe mental illness is and why it matters. The official order of priority for receiving the vaccine is described in a series of Priority Groups, defined by likelihood that COVID infection will be serious and could lead to death. Thus, age defines the top groups.  Priority Group 6 includes adults aged 16 to 65 years in an at-risk group defined by clinical conditions one of which, in an uncomfortable change of grammar in the list, is “are severely mentally ill”. Further clarification comes in the COVID-19 Green Book Chapter 14a which defines severe mental illness as (again the weird change of grammar)  “Individuals with schizophrenia or bipolar disorder, or any mental illness that causes severe functional impairment.” A recent commentary in The Lancet described the rationale as follows: “Patients with severe mental illness, which is patients with psychotic disorder, bipolar disorder, or severe depression, are at a significantly increased risk of being hospitalised or dying from COVID.”

So, the Green Book definition takes it both ways – severity as psychosis and severity as illness causing severe (not defined) functional impairment – whereas the research underlying the decision seems to refer only to the diagnosis-based definition of severity. The advantage of the latter approach is that it is logically consistent with the other priority groups, taking likelihood of hospitalisation or death as the indication for vaccination, and there are at least some plausible mechanisms for such poor outcomes. The disadvantage is that equating severe mental illness with psychosis is clearly wrong and leads to a sense of injustice among those whose illness is severe by quite reasonable more person-centred criteria. The disadvantage of the former (Green Book) approach is that while it acknowledges a wider definition of severity of illness – including, as recommended by some experts, people such as those who have eating disorders or have been given a diagnosis of personality disorder – it is no longer clear why severity thus defined puts somebody in a priority group for vaccination.

It is difficult to escape the conclusion that there is something inherently wrong with the term Severe Mental Illness (SMI). When equated with psychosis it fails to recognize that severity is not adequately captured by diagnosis. When the initials are dropped and it refers to any mental illness, it lacks specificity as a criterion for decision-making.  It would be better replaced with a more accurate and specific terminology.

Mental health in the COVID pandemic: searching for historical comparisons

  • December 31, 2020

I was struck by this week’s variously-reported claim from Adrian James, the current president of RCPsych, that the pandemic is “the biggest hit to mental health since World War 2” (Mail Online) or “poses the greatest threat to mental health since second world war” (Guardian). My initial response was heartsink – yet more melodrama with yet another wartime analogy, especially something I could do without as plucky Britain goes it alone again as we leave the EU. But then I got thinking – where would you look for comparator epochs if you wanted to take this claim at face value? Two candidates come to mind; each covers 5 years.

The threat

First up, the post-war years 1947-1951. Winter 1946/47 was one of the worst winters on record, exacerbated by a fuel shortage for which the Labour Govt (personified in Manny Shinwell) was blamed, at least by the press. Industrial output is estimated to have fallen by 10% in the following year. The Labour Party held on at the 1950 general election but lost the snap election called the next year. In that year, 1951, there was a major influenza epidemic which is estimated to have increased all-cause mortality in those over 65 years by about 50% and causing the greatest number of excess winter deaths in any year in the second half of the twentieth century. Peak death rates in Liverpool were higher than during the Spanish flu epidemic of 1918.

My runner up is the years 1980-84. Thatcherism had a grip and there was social unrest with riots in 1981 in Brixton and Toxteth. On the economic front unemployment ran at 2.5-3 million (more than 10% of the working age population) and the hugely disruptive and divisive miners’ strike dominated 1984.

Set against these threats we have to ask about resilience in the population. The post-war years saw continued rationing and poor housing and poor physical health at levels we go nowhere near approaching. The NHS was founded but will have had little impact on mental health provision. It is difficult to know what to make of any sense of national unity and social solidarity at this time; much is made of growing disillusion with Attlee’s government but in 1951 they still gained more of the popular vote than did Churchill. They lost to our electoral system. Society in the 1980s was more affluent and physically healthier and the NHS had grown hugely, but it was undoubtedly troubled. Thatcher was a divisive leader of a divisive government, notwithstanding populist moves like selling off our social housing and privatising services in support of the idea of a laughably-named share-owning democracy.

The hit

So, there are elements of our current predicament in these previous epochs. How could we judge each in terms of their mental health impact? I find this pretty much impossible to say and we don’t get a clue from the press coverage. As with all NHS bed numbers, psychiatric bed numbers have fallen dramatically from about 155,000 (1953/54) to 67,000 (1987/88) and 18,000 (2019/20) so numbers of admissions won’t help. The Mental Health Acts of 1959 and 1983 will have dramatically changed practice and patterns of service delivery. The only robust measure of population mental health – the suicide rate – has fallen pretty steadily over the decades, with the most consistent evidence for deterioration coming at times of economic recession and mass unemployment.

It would be interesting to see a thoughtful analysis of these questions about the nature of major social upheavals and their consequences for mental health, but if it’s going on it’s not making it into the public domain. A note from March 2020 states that SPI-B received input from academic specialists in history; that committee’s terms of reference for October 2020 do not mention historians as one of the academics from whom advice is being sought.  What a pity.


Subscribe to keep updated!