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The Signature Biobank is a longitudinal repository of biospecimen, psychological, sociodemographic, and diagnostic data that was created in 2012. The Signature Consortium represents a group of approximately one hundred Quebec-based transdisciplinary clinicians and research scientists with various expertise in the field of psychiatry. The objective of the Signature Biobank is to investigate the multi-faceted underpinnings of psychiatric disorders among patients in crisis. The Signature Consortium is expanding and includes new active members that seek to highlight the contributions made by Signature Biobank since its inception. This article details our research protocol, directions, and summarizes contributions. To date, we have collected biological samples (n = 1,986), and questionnaire data (n = 2,085) from psychiatric emergency patients of the Institut universitaire en santé mentale de Montréal (Quebec, Canada), with a large proportion from whom both data types were collected (n = 1,926). In addition to this, a subsample of patients was followed-up at hospital discharge, and two additional outpatient clinic appointments (n = 958 with at least one follow-up). In addition, a socio-demographically matched comparison group of individuals who were not hospitalized for psychiatric disorders (n = 149) was recruited from the surrounding catchment area. To summarize, a systematic review of the literature shows that the Signature Biobank has contributed to better characterizing psychiatric comorbidities, biological profiles, and psychosocial functioning across some of the most common psychiatric disorders, including psychosis, mood, anxiety, and substance use disorders. The Signature Biobank is now one of the world's largest repositories of data collected from patients receiving care at a psychiatric emergency unit., Competing Interests: Declaration of competing interest The authors report no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In schizophrenia cannabis abuse/dependence is associated with poor compliance and psychotic relapse. Despite this, the reasons for cannabis abuse remain elusive, but emotions may play a critical role in this comorbidity. Accordingly, we performed a functional magnetic resonance imaging study of emotional memory in schizophrenia patients with cannabis abuse (dual-diagnosis, DD). Participants comprised 14 DD patients, 14 non-abusing schizophrenia patients (SCZ), and 21 healthy controls (HC) who had to recognize positive and negative pictures while being scanned. Recognition of positive and negative emotions was prominently impaired in SCZ patients, relative to HC, while differences between DD and HC were smaller. For positive and negative stimuli, we observed significant activations in frontal, limbic, temporal and occipital regions in HC; in frontal, limbic and temporal regions in DD; and in temporal, parietal, limbic and occipital regions in the SCZ group. Our results suggest that emotional memory and prefrontal lobe functioning are preserved in DD relative to SCZ patients. These results are consistent with previous findings showing that cannabis abuse is associated with fewer negative symptoms and better cognitive functioning in schizophrenia. Longitudinal studies will need to determine whether the relative preservation of emotional memory is primary or secondary to cannabis abuse in schizophrenia., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Substance use disorders (SUDs) are common in patients with schizophrenia and this comorbidity is associated with a poorer prognosis, relative to non-abusing patients. One hypothesis that has been advanced in the literature is that dual diagnosis (DD) patients may have a different personality profile than non-abusing schizophrenia patients. The present case-control study aimed to characterize levels of personality traits (sensation-seeking, social anhedonia, and impulsivity) in substance abuse/dependence patients with (DD group; n=31) and without schizophrenia (SUD group; n=39), relative to non-abusing schizophrenia patients (SCZ group; n=23), and healthy controls (n=25). Impulsivity was assessed using the Barratt Impulsivity Scale. Sensation-seeking was assessed using the Zuckerman Sensation Seeking Scale. Social anhedonia was assessed with the Chapman Social Anhedonia Scale. We found that sensation-seeking was significantly higher in DD and SUD, relative to SCZ patients. We found that social anhedonia was significantly elevated in DD and SCZ, relative to healthy controls. We found that impulsivity was significantly higher in DD, SCZ and SUD patients, compared to healthy controls. The results suggest that sensation-seeking is prominent in substance abuse/dependence (irrespective of schizophrenia), social anhedonia is prominent in schizophrenia (irrespective of substance abuse/dependence), and impulsivity is prominent in all three populations., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Background: It has been suggested that the dopaminergic system is involved in the pathophysiology of mood disorders. We conducted a multicenter study of families with mood disorders, to investigate a possible linkage with genes coding for dopamine receptor D2, dopamine receptor D3 and tyrosine hydroxylase (TH)., Methods: Twenty three mood disorder pedigrees collected within the framework of the European Collaborative Project on Affective Disorders were analyzed with parametric and non-parametric linkage methods. Various potential phenotypes were considered, from a narrow (only bipolar as affected) to a broad (bipolar+major depressive+schizoaffective disorders) definition of affection status., Results: Parametric analyses excluded linkage for all the candidate genes, even though small positive LOD (Limit of Detection) scores were observed for TH in three families. Non-parametric analyses yielded negative results for all markers., Conclusion: The D2 and D3 dopamine receptors were, therefore, not a major liability factor for mood disorders in our sample, whereas TH may play a role in a subgroup of patients.

Latent inhibition, retarded learning after preexposure to the to-be-conditioned stimulus, has been implied as a tool for the investigation of attentional deficits in schizophrenia and related disorders. The present paper reviews research that used Pavlovian conditioning as indexed by autonomic responses (electrodermal, vasomotor, cardiac) to investigate latent inhibition in adult humans. Latent inhibition has been demonstrated repeatedly in healthy subjects in absence of a masking task that is required in other latent inhibition paradigms. Moreover, latent inhibition of Pavlovian conditioning is stimulus-specific and increases with an increased number of preexposure trials which mirrors results from research in animals. A reduction of latent inhibition has been shown in healthy subjects who score high on questionnaire measures of psychosis proneness and in unmedicated schizophrenic patients. The latter result was obtained in a within-subject paradigm that holds promise for research with patient samples.

The serotonergic system is implicated in the pathogenesis of affective disorders. In particular, the role of the postsynaptic 5-hydroxytryptamine (serotonin) type 2 receptor (5-HT2) has been documented by several studies. The 5-HT2A receptor gene located on chromosome 13 (13q14-21) can be considered a candidate gene for bipolar affective disorder (BPAD). We tested association between a 5-HT2A receptor DNA variant and BPAD using a case-control design. Eighty-three BPAD patients and 129 unrelated normal controls, carefully matched for sex and geographical origin, were studied. Allele and genotype frequencies as well as homo-heterozygote distribution at the 5-HT2A receptor polymorphism were compared between the two groups. No significant allelic or genotypic associations were observed. There was no significant difference for homo-heterozygote distribution between the two groups. These preliminary results may indicate that in our sample the 5-HT2 receptor polymorphism studied is unlikely to play a role in the genetic susceptibility to BPAD.