People with psychosis (the psychosis group) were recruited at the time of their first clinical contact for psychotic symptoms at a general academic hospital (the Hospital Clinic of Barcelona). As part of the Spanish national health system, the hospital offers psychiatric services for all who live in the surrounding catchment area, Esquerra Eixample, in the city of Barcelona. Esquerra Eixample is a relatively homogeneous middle/upper-middle class neighbourhood in the centre of the city. Although it is also possible to seek private care outside of the assigned catchment area, the Hospital Clinic is a regional referral center for psychosis, and in a survey of 2968 admissions to the emergency department of a large general hospital in an adjoining catchment area, there were no individuals with psychosis from Esquerra Eixample.
The psychosis group had a maximum cumulative (lifetime) antipsychotic exposure of 1 week, and no antipsychotic use in the 30 days prior to the study. Participants with psychosis were allowed to receive anti-anxiety medication (lorazepam) the night before blood was drawn, to a maximum of 3 mg, but not on the day of assessment.
The healthy control group (the control group) were recruited using advertisements. We attempted to match the control group to the psychosis group on BMI, age, gender, smoking habit (average number of cigarettes per day), and residence in the catchment area (yes/no) of the Hospital Clinic. All of the participants were White residents of Spain except for one Asian and one North African person in each of the groups. The control group had no current or prior diagnosis of any Axis I DSM-IV15 psychiatric disorder, after being assessed with the structured clinical interview for Axis I DSM-IV psychiatric disorders (SCID-I).16
Additional inclusion and exclusion criteria for all participants were: age from 18 to 64 years; no history of diabetes or other serious medical or neurological condition associated with glucose intolerance or insulin resistance (e.g. Cushing’s disease); not taking a medication associated with insulin resistance (hydrochlorothiazide, furosemide, ethacrynic acid (available in the USA), metolazone, chlortalidone, beta blockers, glucocorticoids, phenytoin, nicotinic acid, ciclosporine, pentamidine or narcotics); no history of cocaine use in the previous 30 days; and have not previously received an antipsychotic or antidepressant medication. Additional exclusion criteria for the control group were no lifetime diagnosis of schizophrenia or major depressive disorder and no current diagnosis of adjustment disorder. All participants gave informed consent for participation in the study, which was conducted under the supervision of the institutional review boards of the authors’ institutions.
Masked to glucose measures, individuals from the two groups that had been recruited were chosen in such a way to assure good matching as a group on gender, age, BMI and smoking habit, and to have an equal number of people in each group. This entailed omitting 6 people from the psychosis group, primarily because of a lower BMI, as well as 22 people in the control group, for purposes of matching.
A secondary, confirmatory analysis was also conducted in which all of the participants who had been recruited were included, and the matching variables were used as covariates.
The psychosis group had a maximum cumulative (lifetime) antipsychotic exposure of 1 week, and no antipsychotic use in the 30 days prior to the study. Participants with psychosis were allowed to receive anti-anxiety medication (lorazepam) the night before blood was drawn, to a maximum of 3 mg, but not on the day of assessment.
The healthy control group (the control group) were recruited using advertisements. We attempted to match the control group to the psychosis group on BMI, age, gender, smoking habit (average number of cigarettes per day), and residence in the catchment area (yes/no) of the Hospital Clinic. All of the participants were White residents of Spain except for one Asian and one North African person in each of the groups. The control group had no current or prior diagnosis of any Axis I DSM-IV15 psychiatric disorder, after being assessed with the structured clinical interview for Axis I DSM-IV psychiatric disorders (SCID-I).16
Additional inclusion and exclusion criteria for all participants were: age from 18 to 64 years; no history of diabetes or other serious medical or neurological condition associated with glucose intolerance or insulin resistance (e.g. Cushing’s disease); not taking a medication associated with insulin resistance (hydrochlorothiazide, furosemide, ethacrynic acid (available in the USA), metolazone, chlortalidone, beta blockers, glucocorticoids, phenytoin, nicotinic acid, ciclosporine, pentamidine or narcotics); no history of cocaine use in the previous 30 days; and have not previously received an antipsychotic or antidepressant medication. Additional exclusion criteria for the control group were no lifetime diagnosis of schizophrenia or major depressive disorder and no current diagnosis of adjustment disorder. All participants gave informed consent for participation in the study, which was conducted under the supervision of the institutional review boards of the authors’ institutions.
Masked to glucose measures, individuals from the two groups that had been recruited were chosen in such a way to assure good matching as a group on gender, age, BMI and smoking habit, and to have an equal number of people in each group. This entailed omitting 6 people from the psychosis group, primarily because of a lower BMI, as well as 22 people in the control group, for purposes of matching.
A secondary, confirmatory analysis was also conducted in which all of the participants who had been recruited were included, and the matching variables were used as covariates.
