Association of Age, Antipsychotic Medication, and Symptom Severity in Schizophrenia With Proton Magnetic Resonance Spectroscopy Brain Glutamate Level: A Mega-analysis of Individual Participant-Level Data

Importance

Proton magnetic resonance spectroscopy (1H-MRS) studies indicate that altered brain glutamatergic function may be associated with the pathophysiology of schizophrenia and the response to antipsychotic treatment. However, the association of altered glutamatergic function with clinical and demographic factors is unclear.

Objective

To assess the associations of age, symptom severity, level of functioning, and antipsychotic treatment with brain glutamatergic metabolites.

Data Sources

The MEDLINE database was searched to identify journal articles published between January 1, 1980, and June 3, 2020, using the following search terms: MRS or magnetic resonance spectroscopy and (1) schizophrenia or (2) psychosis or (3) UHR or (4) ARMS or (5) ultra-high risk or (6) clinical high risk or (7) genetic high risk or (8) prodrome* or (9) schizoaffective. Authors of 114 1H-MRS studies measuring glutamate (Glu) levels in patients with schizophrenia were contacted between January 2014 and June 2020 and asked to provide individual participant data.

Study Selection

In total, 45 1H-MRS studies contributed data.

Data Extraction and Synthesis

Associations of Glu, Glu plus glutamine (Glx), or total creatine plus phosphocreatine levels with age, antipsychotic medication dose, symptom severity, and functioning were assessed using linear mixed models, with study as a random factor.

Main Outcomes and Measures

Glu, Glx, and Cr values in the medial frontal cortex (MFC) and medial temporal lobe (MTL).

Results

In total, 42 studies were included, with data for 1251 patients with schizophrenia (mean [SD] age, 30.3 [10.4] years) and 1197 healthy volunteers (mean [SD] age, 27.5 [8.8] years). The MFC Glu (F1,1211.9 = 4.311, P = .04) and Glx (F1,1079.2 = 5.287, P = .02) levels were lower in patients than in healthy volunteers, and although creatine levels appeared lower in patients, the difference was not significant (F1,1395.9 = 3.622, P = .06). In both patients and volunteers, the MFC Glu level was negatively associated with age (Glu to Cr ratio, F1,1522.4 = 47.533, P < .001; cerebrospinal fluid-corrected Glu, F1,1216.7 = 5.610, P = .02), showing a 0.2-unit reduction per decade. In patients, antipsychotic dose (in chlorpromazine equivalents) was negatively associated with MFC Glu (estimate, 0.10 reduction per 100 mg; SE, 0.03) and MFC Glx (estimate, -0.11; SE, 0.04) levels. The MFC Glu to Cr ratio was positively associated with total symptom severity (estimate, 0.01 per 10 points; SE, 0.005) and positive symptom severity (estimate, 0.04; SE, 0.02) and was negatively associated with level of global functioning (estimate, 0.04; SE, 0.01). In the MTL, the Glx to Cr ratio was positively associated with total symptom severity (estimate, 0.06; SE, 0.03), negative symptoms (estimate, 0.2; SE, 0.07), and worse Clinical Global Impression score (estimate, 0.2 per point; SE, 0.06). The MFC creatine level increased with age (estimate, 0.2; SE, 0.05) but was not associated with either symptom severity or antipsychotic medication dose.

Conclusions and Relevance

Findings from this mega-analysis suggest that lower brain Glu levels in patients with schizophrenia may be associated with antipsychotic medication exposure rather than with greater age-related decline. Higher brain Glu levels may act as a biomarker of illness severity in schizophrenia.

Relation of inflammatory markers with symptoms of psychotic disorders: a large cohort study

AIMS

Immunological mechanisms may play a role in symptomatology of patients with a psychotic disorder. Besides metabolic problems and medication use, inflammatory processes that may occur due to the disorder may cause increased inflammatory markers and concurrent psychiatric symptoms. The aim of this study is to investigate whether levels of C-reactive protein (CRP) and white blood cell count (WBC) are related to positive and negative symptoms of psychotic disorders, and whether age, gender, duration of illness, smoking behavior, haloperidol equivalents, mediation use, body mass, and metabolic syndrome affect this relation.

METHODS

CRP and WBC values of 2123 patients with a psychotic disorder were related to positive and negative symptoms measured with a psychiatric interview. CRP was analyzed by survival analysis accounting for detection limit and WBC by linear mixed model analysis. In case of a significant association, the confounding factors were added to the model.

RESULTS

Both WBC and CRP were related to both positive and negative symptoms, even after correction for age, gender, smoking, use of medication and metabolic problems. Of the covariates, gender, metabolic problems, smoking and statins also showed a strong association with inflammatory markers.

CONCLUSIONS

This study in a large patient-group confirmed that inflammatory markers are related to psychotic disorders, particularly negative symptoms. Future studies could use more precise measures of inflammatory markers and measure symptomatic state at specific moments in illness progression.

Exploring the use of Routine Outcome Monitoring in the treatment of patients with a psychotic disorder

BACKGROUND

Routine Outcome Monitoring (ROM) has become part of the treatment process in mental health care. However, studies have indicated that few clinicians in psychiatry use the outcome of ROM in their daily work. The aim of this study was to explore the degree of ROM use in clinical practice as well as the explanatory factors of this use.

METHODS

In the Northern Netherlands, a ROM-protocol (ROM-Phamous) for patients with a psychotic disorder has been implemented. To establish the degree of ROM-Phamous use in clinical practice, the ROM results of patients (n=204) were compared to the treatment goals formulated in their treatment plans. To investigate factors that might influence ROM use, clinicians (n=32) were asked to fill out a questionnaire about ROM-Phamous.

RESULTS

Care domains that were problematic according to the ROM-Phamous results were mentioned in the treatment plan in 28% of cases on average (range 5-45%). The use of ROM-Phamous in the treatment process varies considerably among clinicians. Most of the clinicians find ROM-Phamous both useful and important for good clinical practice. In contrast, the perceived ease-of-use is low and most clinicians report insufficient time to use ROM-Phamous.

CONCLUSIONS

More frequent ROM use should be facilitated in clinicians. This could be achieved by improving the fit with clinical routines and the ease-of-use of ROM systems. It is important for all stakeholders to invest in integrating ROM in clinical practice. Eventually, this might improve the diagnostics and treatment of patients in mental health care.

[Clinical application of ROM in psychosis]

AIM

The use of 'routine outcome monitoring' (ROM) in mental health care has increased widely during the past decade. However, little is known about the use of ROM outcome in daily clinical practice. We investigated to what extent ROM results were reflected in psychotic patients' treatment plans.

DESIGN

Cross-sectional study.

METHOD

The ROM-Phamous, a ROM-protocol for patients with psychotic disorders in which data is collected on the basis of interviews, questionnaires and physical examination was implemented in the northern Netherlands. A random sample of 100 patients was extracted from the 2010 ROM database (n = 1040), from which we determined the prevalence of a number of problem areas. We then investigated whether these problems were reflected in patients' treatment plans.

RESULTS

The sample consisted of 63 men and 37 women, with a mean age of 44 years and a mean duration of illness of 18 years. The prevalence of symptoms and psychosocial problems was 13-37%; the prevalence of cardiovascular risk factors was 11-86%. The majority of problems identified with ROM were not reflected in patients' treatment plans; the opposite also occurred: psychosocial problems, in particular, mentioned in the treatment plans were not always identified with ROM.

CONCLUSION

ROM and treatment should ideally be integrated in mental-health services, but currently appear to be separate processes. If improvement of integration of ROM and clinical practice succeeds it could lead to improvement of care for psychiatric patients. Further investigation is warranted. Conflict of interest and financial support: ICMJE forms provided by the authors are available online along with the full text of this article.

Normal brain activation in schizophrenia patients during associative emotional learning

Emotional deficits are among the core features of schizophrenia and both associative emotional learning and the related ability to verbalize emotions can be reduced. We investigated whether schizophrenia patients demonstrated impaired function of limbic and prefrontal areas during associative emotional learning. Patients and controls filled out an alexithymia questionnaire and performed an associative emotional learning task with positive, negative and neutral picture-word pairs during fMRI scanning. After scanning, they indicated for each pair whether they remembered it. We conducted standard GLM analysis and Independent Component Analysis (ICA). Both the GLM results and task-related ICA components were compared between groups. The alexithymia questionnaire indicated more cognitive-emotional processing difficulties in patients than controls, but equal experienced intensity of affective states. Patients remembered less picture-word pairs, irrespective of valence. GLM analysis showed significant visual, temporal, amygdalar/hippocampal, and prefrontal activation in all subjects. ICA identified a network of brain areas similar to GLM, mainly in response to negative stimuli. Neither analysis showed differences between patients and controls during learning. Although in previous studies schizophrenia patients showed abnormalities in both memory and emotion processing, neural circuits involved in cross-modal associative emotional learning may remain intact to a certain degree, which may have potential consequences for treatment.