Prevalence of multimorbidity in people with and without severe mental illness: a systematic review and meta-analysis

BACKGROUND

People with severe mental illness, such as schizophrenia-spectrum disorder and bipolar disorder, face poorer health outcomes from multiple chronic illnesses. Physical multimorbidity, the coexistence of two or more chronic physical conditions, and psychiatric multimorbidity, the coexistence of three or more psychiatric disorders, are both emerging concepts useful in conceptualising disease burden. However, the prevalence of physical and psychiatric multimorbidity in this cohort is unknown. This study aimed to estimate the absolute prevalence of both physical and psychiatric multimorbidity in people with severe mental illness, and also compare the odds of physical multimorbidity prevalence against people without severe mental illness.

METHODS

We searched CINAHL, EMBASE, PubMed, and PsycINFO from inception until Feb 15, 2024, for observational studies that measured multimorbidity prevalence. To be included, studies had to have an observational study design, be conducted in an adult population (mean age ≥18 years) diagnosed with either schizophrenia-spectrum disorder or bipolar disorder, and include a measurement of occurrence of either physical multimorbidity (≥2 physical health conditions) or psychiatric multimorbidity (≥3 psychiatric conditions total, including the severe mental illness). From control studies, a random-effects meta-analysis compared odds of physical multimorbidity between people with and without severe mental illness. Absolute prevalence of physical and psychiatric multimorbidity in people with severe mental illness was also calculated. Sensitivity and meta-regression analyses tested an array of demographic, diagnostic, and methodological variables.

FINDINGS

From 11 144 citations we included 82 observational studies featuring 1 623 773 individuals with severe mental illness (specifically schizophrenia-spectrum disorder or bipolar disorder), of which 21 studies featured 13 235 882 control individuals without severe mental illness (descriptive data for the entire pooled cohorts were not available for numbers of males and females, age, and ethnicity). This study did not feature involvement of people with lived experience. The odds ratio (OR) of physical multimorbidity between people with and without severe mental illness was 2·40 (95% CI 1·57-3·65, k=11, p=0·0009). This ratio was higher in younger severe mental illness populations (mean age ≤40 years, OR 3·99, 95% CI 1·43-11·10) compared with older populations (mean age >40 years, OR 1·55, 95% CI 0·96-2·51; subgroup differences p=0·0013). For absolute prevalence, 25% of those with severe mental illness have physical multimorbidity (95% CI 0·19-0·32, k=29) and 14% have psychiatric multimorbidity (95% CI 0·08-0·23, k=21).

INTERPRETATION

This is the first meta-analysis to estimate physical alongside psychiatric multimorbidity prevalence, showing that these are common in people with schizophrenia-spectrum disorder and bipolar disorder. The greater burden of physical multimorbidity in people with severe mental illness compared with those without is higher for younger cohorts, reflecting a need for earlier intervention. Our findings speak to the utility of multimorbidity for characterising the disease burden associated with severe mental illness, and the importance of facilitating integrated physical and mental health care.

FUNDING

None.

Association of symptom severity and cerebrospinal fluid alterations in recent onset psychosis in schizophrenia-spectrum disorders - An individual patient data meta-analysis

Neuroinflammation and blood-cerebrospinal fluid barrier (BCB) disruption could be key elements in schizophrenia-spectrum disorderś(SSDs) etiology and symptom modulation. We present the largest two-stage individual patient data (IPD) meta-analysis, investigating the association of BCB disruption and cerebrospinal fluid (CSF) alterations with symptom severity in first-episode psychosis (FEP) and recent onset psychotic disorder (ROP) individuals, with a focus on sex-related differences. Data was collected from PubMed and EMBASE databases. FEP, ROP and high-risk syndromes for psychosis IPD were included if routine basic CSF-diagnostics were reported. Risk of bias of the included studies was evaluated. Random-effects meta-analyses and mixed-effects linear regression models were employed to assess the impact of BCB alterations on symptom severity. Published (6 studies) and unpublished IPD from n = 531 individuals was included in the analyses. CSF was altered in 38.8 % of individuals. No significant differences in symptom severity were found between individuals with and without CSF alterations (SMD = -0.17, 95 %CI -0.55-0.22, p = 0.341). However, males with elevated CSF/serum albumin ratios or any CSF alteration had significantly higher positive symptom scores than those without alterations (SMD = 0.34, 95 %CI 0.05-0.64, p = 0.037 and SMD = 0.29, 95 %CI 0.17-0.41p = 0.005, respectively). Mixed-effects and simple regression models showed no association (p > 0.1) between CSF parameters and symptomatic outcomes. No interaction between sex and CSF parameters was found (p > 0.1). BCB disruption appears highly prevalent in early psychosis and could be involved in positive symptomś severity in males, indicating potential difficult-to-treat states. This work highlights the need for considering BCB breakdownand sex-related differences in SSDs clinical trials and treatment strategies.

Inflammatory cerebrospinal fluid markers in schizophrenia spectrum disorders: A systematic review and meta-analysis of 69 studies with 5710 participants

BACKGROUND

There is increasing evidence of immune dysregulation and neuroinflammation occurring in schizophrenia. The aim of this study is to combine studies on routine CSF parameters, as well as cytokines and inflammatory proteins, in individuals with schizophrenia spectrum disorders.

METHODS

CSF parameters were summated and inverse variance meta-analyses using a random effects model were performed comparing mean difference or odds ratios. Between study heterogeneity was assessed using the I2 statistic. Quality assessment and sensitivity analyses were performed.

RESULTS

There were 69 studies of 5710 participants, including 3180 individuals with schizophrenia spectrum disorders. Averaged CSF parameters were within normal limits, however, between 3.1 % and 23.5 % of individual cases with schizophrenia spectrum disorders had an abnormal CSF result: Protein (abnormal in 23.5 % cases), albumin (in 18.5 %), presence of oligoclonal bands (in 9.3 %), white blood cell count (in 3.6 %), and IgG levels (3.1 %). Meta-analysis of 55 studies with non-psychiatric controls demonstrated a significant increase in CSF total protein (MD: 3.50, CI: 0.12-6.87), albumin ratio (MD: 0.55, CI: 0.02-0.09), white cell count (MD: 0.25, CI: 0.05-0.46), IL-6 (SMD: 0.53, CI: 0.29 to 0.77) and IL-8 (SMD: 0.56, CI: 0.11 to 1.01). Sensitivity analysis did not alter findings.

CONCLUSION

Abnormal CSF parameters, cytokines and inflammatory proteins were found in a significant proportion of individuals with schizophrenia spectrum disorders. This may indicate alterations to blood brain barrier function and permeability, CSF flow dynamics or neuroinflammation. Further research is needed to explore these potential mechanisms.

Making meaning of multimorbidity and severe mental illness: A viewpoint

People living with severe mental illness, such as schizophrenia and bipolar affective disorder, frequently experience poorer physical health compared to those without mental illness. This issue has hitherto been approached through the disease-centred construct of comorbidity, where subsequent conditions are viewed as secondary to an 'index condition'. In contrast, this Viewpoint sets out to explain why multimorbidity, a patient-centred concept that instead refers to the coexistence of multiple chronic illnesses, is a more versatile and robust framework for tackling the issue of poor physical health in people with severe mental illness. In establishing this argument, this Viewpoint has sought to address three key areas. First, this article will discuss the epidemiology of both physical and psychiatric multimorbidity, with respect to how they manifest at greater frequency and at younger ages in people with severe mental illness. Second, the profound consequences of this multimorbidity burden will be explored, with respect to the 'three D's' of death (premature mortality), disability (functional impacts) and deficit (health-economic impacts). Finally, the utility of multimorbidity as a framework will be illustrated through a proposal for a three-dimensional multimorbidity construct composed of (1) quantity, (2) severity and (3) duration of an individual's chronic illnesses. Consequently, this Viewpoint aims to capture why it is necessary for modern psychiatry to grasp the concept of multimorbidity to facilitate holistic healthcare for people living with severe mental illness.

Alteration patterns of peripheral concentrations of cytokines and associated inflammatory proteins in acute and chronic stages of schizophrenia: a systematic review and network meta-analysis

BACKGROUND

Immune system dysfunction is considered to play an aetiological role in schizophrenia spectrum disorders, with substantial alterations in the concentrations of specific peripheral inflammatory proteins, such as cytokines. However, there are inconsistencies in the literature over which inflammatory proteins are altered throughout the course of illness. Through conducting a systematic review and network meta-analysis, this study aimed to investigate the patterns of alteration that peripheral inflammatory proteins undergo in both acute and chronic stages of schizophrenia spectrum disorders, relative to a healthy control population.

METHODS

In this systematic review and meta-analysis, we searched PubMed, PsycINFO, EMBASE, CINAHL, and the Cochrane Central Register of Controlled Trials from inception to March 31, 2022, for published studies reporting peripheral inflammatory protein concentrations in cases of people with schizophrenia-spectrum disorders and healthy controls. Inclusion criteria were: (1) observational or experimental design; (2) a population consisting of adults diagnosed with schizophrenia-spectrum disorders with a specified indicator of acute or chronic stage of illness; (3) a comparable healthy control population without mental illness; (4) a study outcome measuring the peripheral protein concentration of a cytokine, associated inflammatory marker, or C-reactive protein. We excluded studies that did not measure cytokine proteins or associated biomarkers in blood. Mean and SDs of inflammatory marker concentrations were extracted directly from full-text publshed articles; articles that did not report data as results or supplementary results were excluded (ie, authors were not contacted) and grey literature and unpublished studies were not sought. Pairwise and network meta-analyses were done to measure the standardised mean difference in peripheral protein concentrations between three groups: individuals with acute schizophrenia-spectrum disorder, individuals with chronic schizophrenia-spectrum disorder, and healthy controls. This protocol was registered on PROSPERO, CRD42022320305.

FINDINGS

Of 13 617 records identified in the database searches, 4492 duplicates were removed, 9125 were screened for eligibility, 8560 were excluded after title and abstract screening, and three were excluded due to limited access to the full-text article. 324 full-text articles were then excluded due to inappropriate outcomes, mixed or undefined schizophrenia cohorts, or duplicate study populations, five were removed due to concerns over data integrity, and 215 studies were included in the meta-analysis. 24 921 participants were included, with 13 952 adult cases of schizophrenia-spectrum disorder and 10 969 adult healthy controls (descriptive data for the entire cohort were not available for age, numbers of males and females, and ethnicity). Concentration of interleukin (IL)-1β, IL-1 receptor antagonist (IL-1RA), soluble interleukin-2 receptor (sIL-2R), IL-6, IL-8, IL-10, tumour necrosis factor (TNF)-α, and C-reactive protein were consistently elevated in both individuals with acute schizophrenia-spectrum disorder and chronic schizophrenia-spectrum disorder, relative to healthy controls. IL-2 and interferon (IFN)-γ were significantly elevated in acute schizophrenia-spectrum disorder, while IL-4, IL-12, and IFN-γ were significantly decreased in chronic schizophrenia-spectrum disorder. Sensitivity and meta-regression analyses revealed that study quality and a majority of the evaluated methodological, demographic, and diagnostic factors had no significant impact on the observed results for most of the inflammatory markers. Specific exceptions to this included: methodological factors of assay source (for IL-2 and IL-8), assay validity (for IL-1β), and study quality (for transforming growth factor-β1); demographic factors of age (for IFN-γ, IL-4, and IL-12), sex (for IFN-γ and IL-12), smoking (for IL-4), and BMI (for IL-4); and diagnostic factors including diagnostic composition of schizophrenia-spectrum cohort (for IL-1β IL-2, IL-6, and TNF-α), antipsychotic-free cases (for IL-4 and IL-1RA), illness duration (for IL-4), symptom severity (for IL-4), and subgroup composition (for IL-4).

INTERPRETATION

Results suggest that people with schizophrenia-spectrum disorders have a baseline level of inflammatory protein alteration throughout the illness, as reflected by consistently elevated pro-inflammatory proteins, hypothesised here as trait markers (eg, IL-6), while those with acute psychotic illness might have superimposed immune activity with increased concentrations of hypothesised state markers (eg, IFN-γ). Further research is required to determine whether these peripheral alterations are reflected within the central nervous system. This research facilitates an entry point in understanding how clinically relevant inflammatory biomarkers might one day be useful to the diagnosis and prognostication of schizophrenia-spectrum disorders.

FUNDING

None.

Forensic psychiatry for people with learning disability

The forensic psychiatry of learning disability is a subspeciality which exists on the ‘borderlines’ between other areas. It takes in information from forensic psychiatry, learning disability, child and adolescent psychiatry, psychology, genetics and pharmacology to name but a few.

The acute-phase mediator serum amyloid A is associated with symptoms of depression and fatigue

OBJECTIVE

Establish whether inflammatory biomarkers-serum amyloid A (SAA), C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α)-are related to key symptoms of depression, including anxiety and fatigue, in a cross-sectional, out-patient setting to identify biomarkers that reflect psychiatric symptomatology in a naturalistic, real-life population.

METHODS

We measured SAA, CRP, IL-6, and TNF-α in plasma samples from 89 adult psychiatric out-patients by multiplex, high-sensitivity electrochemiluminescent assays. Psychiatric symptoms were evaluated using the Hamilton Depression Rating Scale (HAMD-17), the Patient Health Questionnaire (PHQ-9), and the Center for Epidemiological Studies Depression Scale (CES-D).

RESULTS

Plasma SAA was most robustly associated with depressive symptoms across diagnostic boundaries in this cohort of out-patients. Elevated SAA was significantly associated with higher total scores on the HAMD-17 scale and correlated with multiple scale items that rated symptoms of fatigue and depressed mood, but not with anxiety-related items.

CONCLUSIONS

SAA might constitute a cross-diagnostic marker indicative of depressed mood and fatigue in a naturalistic patient setting. Because SAA activates Toll-like receptors 2 and 4, present on macrophages and glial cells, its association with depression severity could also implicate this inflammatory mediator in the pathogenesis of mood disorders.

Long-term outcome from a medium secure service for people with intellectual disability

BACKGROUND

The purpose of this paper is to describe long-term outcomes for patients discharged over a 12-year period from a medium secure service for people with intellectual disabilities (ID).

METHODS

A cohort study using case-notes analysis and a structured interview of current key informants.

RESULTS

Eleven per cent of the sample was reconvicted. Fifty-eight per cent of the sample showed offending-like behaviour that did not lead to police contact. Twenty-eight per cent of the sample was currently detained in hospital under the Mental Health Act. The presence of a personality disorder, a history of theft or burglary, and young age increased the risk of reconviction. Contact with the police was less likely in those with schizophrenia. Re-admission to hospital was associated with the presence of offending-like behaviours, rather than any specific diagnosis.

CONCLUSION

In terms of reconviction, these results are good compared with those from general forensic services; however, behavioural problems continue for many years and are managed without recourse to the criminal justice system. There is a borderline group whose needs are poorly defined and serviced. Declaration of interests Horizon National Health Service Trust, the managing authority of the service, gave the grant for this study; the corresponding author was working in the service.

Dengue virus type 2 in Cuba, 1997: conservation of E gene sequence in isolates obtained at different times during the epidemic

It was recently reported that disease severity increased during the 1997 Cuban dengue 2 virus epidemic and it was suggested that this might be explained by the appearance of neutralization resistant escape mutants. We investigated these observations and ideas by sequencing 20 dengue 2 virus isolates obtained during the early (low case fatality rate) and the late (high case fatality rate) phases of the outbreak. Our results showed total conservation of the E gene sequence for these isolates suggesting that the selection of envelope gene escape mutants was not the determinant of increased disease severity. Alignment of these sequences with those available in GenBank, followed by Maximum likelihood phylogenetic analysis generated a tree, which indicated that our isolates are closely related to the virus that circulated in Venezuela in 1997/98 and subsequently in Martinique in 1998. This "American/Asian" genotype has therefore gradually dispersed across the Caribbean region during the past 5 years.

Service-user and professional issues

A review of the current literature on service-user and professional issues revealed a distinctive pattern of concerns. Whilst these mainly have an origin in the wider world of disability, they have a relevance for forensic services. Advocacy, sexuality, abuse, offending, victimology, emergency management of behaviour, law, social exclusion, models of disability and research ethics dominated the literature. There was a paucity of work on professional development or service design, although this may have been an artefact resulting from the search methodology. In the view of the present author, the striking omissions were economics, the ethics of treatment and confidentiality, and the role of society in making decisions for those who cannot make decisions for themselves. The emphasis was on the 'libertarian' disability agenda and the more 'paternalistic' concerns of forensic services were somewhat neglected.

Audit to improve use of central venous catheters

Staff in one trust undertook an audit of the management of central venous catheters in the intensive care unit with the aim of measuring practice against current good practice guidelines. Specific areas of interest were infection rates, aseptic technique and training.

Primitive (developmental) reflexes, tardive dyskinesia and intellectual impairment in schizophrenia

Primitive reflexes, also known as higher cerebral, developmental or release reflexes, are present in foetal and infant life, and are found in certain organic brain diseases. They are normally regarded as non-localising signs of cerebral immaturity or dysfunction which are uncommon in the normal population. The main aims of this study were to find out whether recent reports of an association between primitive reflexes and severity of cognitive impairment in dementia and between primitive reflexes and tardive dyskinesia in schizophrenia could be replicated in a younger population of schizophrenic patients. Forty-eight schizophrenic patients (mean age 51 years) were assessed for primitive reflexes, involuntary movements and cognitive function, and 58% exhibited at least one primitive reflex and 23% at least two. No association was found between primitive reflexes and cognitive impairment or between primitive reflexes and tardive dyskinesia. These results fail to support the hypothesis that the presence of primitive reflexes in some schizophrenic patients indicates a vulnerability to tardive dyskinesia and intellectual decline with advancing age, but long-term prospective studies would be required to test this hypothesis adequately. Nevertheless, these findings support the notion of neurodevelopmental or neurodegenerative brain disease in at least a proportion of patients with schizophrenia.

Selenium toxicosis in feeder pigs

Selenium toxicosis was diagnosed in feeder pigs on a central Michigan farm. Use of a commercial supplement, found to contain approximately 20 times the intended Se concentration, resulted in a Se concentration of 8.1 mg/kg of the complete feed. This was fed for 34 days during which daily feed consumption decreased approximately 35%, several pigs developed weakness and forelimb paresis, and 1 pig died. The highest serum Se concentration measured was 1,550 ng/ml (normal range, 140 to 190 ng/ml). Normal feed consumption returned when an alternative feed was provided. Mean serum Se concentrations of representative pigs, monitored over the subsequent 26 days, decreased from 905 to 258 ng/ml. Histologic examination of a recovering pig revealed skeletal and cardiac myopathy and bilaterally symmetric malacia of the gray matter of the ventral horns of the spinal cord. During the developing toxicosis, the pigs consumed an estimated 11.4 mg of Se/pig/d.

A follow-up study of Asian problem drinkers

This is a follow-up study of 70 patients referred for treatment of drinking problems. At the end of 12 months, it was found that 60% remained in abstinence, 8.5% social drinking, 28.5% relapsed or defaulted and 3% died. A poor outcome was observed in patients between 20 and 39 years old as compared to those between 40 and 59 years old. Patients with SADQ scores of less than 20 had good outcomes. However, there was no significant difference between Indian and Chinese patients. Marital status and social class were not useful predictors of outcome.

Clinical economics education in the International Clinical Epidemiology Network. INCLEN Economics Faculty

The application of rigorous epidemiologic methods to clinical questions has broadened the scope of research in epidemiology and enhanced the quality of clinical research. The International Clinical Epidemiology Network (INCLEN) has enabled physicians from developing countries to obtain training in epidemiologic methods and to provide leadership in clinical epidemiology in their home schools of medicine. The INCLEN program has recently incorporated another major theme of research training, clinical economics, which introduces research related to the effective use of limited resources. This article describes the rationale for the development of the INCLEN Clinical Economics program, outlines its organization and curriculum, and explores the challenges to its successful implementation.

Psychosis associated with HIV infection

Five cases of psychiatric illness, presenting as functional psychosis, occurring in male homosexuals with human immunodeficiency virus (HIV) infection are described and compared with similar cases in the literature. The association between psychosis and infection with HIV is discussed with particular emphasis on the significance of functional versus organic presentation.

Trypanosoma cruzi and Trypanosoma rangeli in Saimiri sciureus from Bolivia and Saguinus mistax from Brazil

Examination of blood films for trypanosomes in primates housed at the Tulane University Delta Regional Primate Research Center showed that 47% (32/68) of the Bolivian Saimiri sciureus and 51% (68/135) of Brazilian Saguinus mistax harbored one or more types: Trypanosoma (Schizotrypanum) cruzi in 6% to 7% and Trypanosoma (Herpetosoma) spp. or Trypanosoma (Megatrypanum) spp. in 39% and 45%, respectively. Trypanosomes were isolated from a sample of the infected monkeys and morphobiological studies were carried out. Both T. cruzi and Trypanosoma rangeli were demonstrated. The transmission of T. rangeli by Rhodnius prolixus, Rhodnius neglectus, and Triatoma infestans was assessed: only R. prolixus transmitted the infection by bite. T. rangeli has not been found previously in Bolivia, nor has any trypanosome been reported previously in Saguinus mistax.