Rosa Jurado-Barba

Characterizing cannabis-induced psychosis: A study with prepulse inhibition of the startle reflex

Cannabis-induced psychotic disorder (CIPD) refers to psychotic symptoms that arise in the context of cannabis intoxication. Prepulse inhibition (PPI) deficits have been extensively identified in schizophrenia and in cannabis abusers. We aimed to characterize PPI in CIPD patients. We used a sample of 48 CIPD patients, 54 schizophrenia patients and cannabis abuse (SCHZ), 44 cannabis dependents (CD), and 44 controls. CIPD, SCHZ and CD were abstinent of cannabis consumption for 9 months. Participants were assessed with PPI at 30, 60, and 120 ms. At 30 ms, CIPD showed lower PPI levels than controls, and SCHZ obtained worse functioning than controls and CD. At 60 ms, only SCHZ exhibited worse PPI percentages (of object) than controls. Finally, at 120 ms, CIPD showed higher PPI levels than SCHZ, and SCHZ obtained lower percentages than controls. We found that CIPD and SCHZ patients showed deficits at the most pre-attentional levels, whereas CIPD patients performed better than SCHZ at higher attentional levels. These results suggest that CIPD constitutes a different group of patients than that of SCHZ. Deficits in PPI functioning at 30 ms could be a useful psychophysiological measure to detect CIPD patients, who are frequently confused with cannabis abusers whose symptoms may mimic that of schizophrenia.

Association between maltreatment and polydrug use among adolescents

Different studies have related sexual and physical abuse during childhood and adolescence to the development of substance abuse disorders. Nevertheless, we are not aware of the role that other more common maltreatment types, such as neglect, will play among the most risky pattern of consumption: the polydrug use. A clinical sample of 655 adolescents, divided into two groups: polydrug users and non-polydrug users, were assessed on their pattern of drug consumption, history of childhood maltreatment, current psychopathology and their family history of alcoholism. Polydrug users had a greater prevalence of all types of maltreatment, although the most associated to this group were sexual abuse and emotional neglect. Other relevant variables to adolescent consumption were: the diagnosis of depressive disorder, the presence of anxiety traits and the family history of alcohol dependence. Polydrug users have higher risks of having had problems during infancy and adolescence, such as maltreatment and other psychopathological conditions, with the addition of family history of alcoholism. Accordingly, practitioners should take into account that those variables may influence polydrug abuse because it is the most risky pattern for subsequent dependence of substances, and they should always be considered during treatment.

Sensory Gating Deficits in First-Episode Psychosis: Evidence From Neurophysiology, Psychophysiology, and Neuropsychology.

Abstract Sensory gating deficits are commonly found in patients with schizophrenia. However, there is still scarce research on this issue. Thirty-eight patients with first-episode psychosis (FEP) were compared to thirty-eight controls. A condition-test paradigm of event-related potentials (ERP), prepulse inhibition (PPI), and some specific tasks of the MATRICS Consensus Cognitive Battery (MCCB) were used (i.e., TMT, BACS-SC, and Fluency for processing speed and CPT-IP for attention and vigilance). The ERP components measured were P50, N1, and P2. The PPI intervals examined were 30, 60, and 120 msec. Regarding the MCCB, processing speed and attention/vigilance cognitive domains were selected. FEP patients showed significant deficits in N1 and P2 components, at 30 and 60 PPI levels and in all the MCCB subtests selected. We obtained significant relationships in N1 with PPI-60, and with one MCCB subtest for processing speed. In addition, this same subtest showed significant association with P2. Therefore, sensory gating functioning is widely impaired since the very early stages of schizophrenia.

Cognitive impairments in patients with first episode psychosis: The relationship between neurophysiological and neuropsychological assessments.

Cognitive deficits in schizophrenia have been widely reported. Neurophysiological and neuropsychological assessments have been conducted to study these impairments. Event-related potentials (ERPs) are relevant markers of cognitive deficits in schizophrenia, and reductions in specific ERP components have been found. The MATRICS Consensus Cognitive Battery (MCCB) was developed to obtain a consensus battery for the assessment of cognitive deficits in schizophrenia. Here, we aimed to study modulations of several ERP components in first episode psychosis (FEP). We also examined neuropsychological deficits using the MCCB, and correlations between ERP and MCCB impairments. Thirty-eight FEP patients were compared to thirty-eight healthy controls. The following ERP components were examined: P1, N1, MMN, P2, early-P3 and late-P3. We used an auditory three-stimulus oddball paradigm, with standard (60%), target (20%) and distractor (20%) stimuli. FEP patients showed significantly lower amplitudes of P2, early-P3 and late-P3 components. FEP patients also showed significant deficits in all the MCCB cognitive domains. Finally, correlational analyses found strong associations between amplitudes of P2, early-P3 and late-P3 components and MCCB tests for attention and speed of processing. These findings indicate that deficits in late auditory ERP components are present in FEP, whereas early components are preserved. These reductions in late ERP components were related to attentional deficits in FEP as assessed by MCCB. These findings indicate that MCCB is a valid battery for studying cognitive impairments in the initial stages of schizophrenia, and highlight the utility of converging neurophysiological and neuropsychological measures to examine attentional impairments in schizophrenia.

Cannabis Abuse Effects on Prepulse Inhibition in Patients With First Episode Psychosis in Schizophrenia

Deficits in prepulse inhibition (PPI) and cannabis abuse are consistently found in schizophrenia. The authors studied PPI deficits in first episode psychosis (FEP) with schizophrenia and cannabis abuse influence. Thirty-five patients with FEP and 22 control subjects were examined. Patients were divided into cannabis use disorder (CUD) (N=21) and non-CUD (N=14). Startle measures were as follows: PPI at 30, 60, and 120 msec. Patients with CUD and patients without CUD showed lower PPI at 30 msec than control subjects. At 60 msec, patients with CUD obtained higher %PPI than patients without CUD, and patients without CUD obtained lower levels than control subjects. These findings show that cannabis abuse may improve PPI in patients with FEP at some levels.

Stress induced by the socially evaluated cold-pressor test cause equivalent deficiencies of sensory gating in male subjects with schizophrenia and healthy controls

It is known that patients with schizophrenia show a deficiency in the prepulse inhibition reflex (PPI). These patients display abnormalities in autonomic nervous system and hypothalamic-pituitary-adrenal function and may have an altered sensitivity to stress. To date, no studies have been carried out to determine the effect of acute stress on the PPI. We investigated whether there was a differential response in reactivity to acute stress caused by the socially evaluated cold-pressor test (SECPT) in a sample of 58 chronic male patients with schizophrenia and 28 healthy control subjects. PPI, salivary cortisol and heart rate (HR) were measured. The patients were evaluated in two sessions (with and without the SECPT) 72 h apart and basal measurements were carried out and 30 min post-startle probe. We found an increase in salivary cortisol levels and the HR with SECPT condition in both groups and a significantly lower PPI% in patients with schizophrenia. The most relevant findings of this study are that the impairment of the PPI is increased by stress. Stress-induced increase in cortisol in both groups, mainly in healthy control group which allows us to hypothesize that at least such deterioration may be due to the hypercortisolemia caused by the SECPT.

Psychological symptomatology and impaired prepulse inhibition of the startle reflex are associated with cannabis-induced psychosis

Background: Cannabis-induced psychotic disorder (CIPD) is a psychiatric disorder induced by cannabis consumption. The psychological and psychophysiological features of this disorder are still unknown. We aimed to examine the psychological, personality and psychophysiological features of patients with CIPD. This study is an analytical extension of our previously published data, which previously found prepulse inhibition (PPI) deficits in the CIPD group used in this current paper. Methods: We used a sample of 45 patients with CIPD. After 9 months of follow up, these patients were assessed with a Symptom Checklist-90-R (SCL-90-R) questionnaire of psychopathology, with the Eysenck Personality Questionnaire, and with a psychophysiological paradigm of inhibition of the startle reflex (PPI). These results were compared with a group of patients with schizophrenia and cannabis abuse (SCHZ) (n = 54); patients with cannabis dependence (CD) (n = 21); and healthy controls (n = 50). Results: CIPD patients obtained significant higher scores in the SCL-90-R subscale of neuroticism. These patients showed PPI percentages similar to SCHZ patients within early attentional levels (30 ms). The variables with greater correlation, and that appeared in the CIPD group were interpersonal sensitivity, depression and phobia. Conclusions: Neurotic symptomatology and difficulties in inhibition of the startle reflex might be risk factors for developing CIPD.

P3 Component as a Potential Endophenotype for Control Inhibition in Offspring of Alcoholics

Aims To assess inhibitory processes and the ongoing event-related potential (ERP) activity of offspring of alcoholics (OA) during a Go/No-Go task, with the purpose of characterizing possible psychophysiological endophenotypes for alcohol-dependent vulnerability. Short summary EEG recordings and ERP measurements of young adults with positive and negative family history of alcoholism where obtained while they performed a Go/No-Go task to assess inhibitory processes. Offspring of alcoholics showed a different ERP pattern compared to the control group and exerted greater effort than the control group. Methods ERP measurements were obtained by electroencephalogram (EEG) recordings of 65 participants divided into two groups: one group of 30 subjects with positive family history of alcoholism and a control group of 35 subjects with negative family history of alcoholism. They performed a Go/No-Go task, where each individual was required to classify visual stimuli by colour (Go) and inhibit their response to a No-Go signal. Results OA have higher P3 amplitudes during the Go condition in all of the regions analysed and higher No-Go P3 amplitudes than control subjects in the frontal region. Unlike controls, OA have no differences between the P3 amplitudes across conditions. Conclusions The absence of differences between the P3 Go and No-Go observed in the OA group can be interpreted as a possible alteration related with inhibition, in a way that they may need to recruit similar resources for inhibitory and classificational processes for both conditions. Therefore, the P3 component may be considered as a useful endophenotype and a vulnerability marker to develop addictive behaviour.

Single Case Study: Neuropsychological Functioning in a Patient Diagnosed with Intermittent Explosive Disorder Pre and Post Neurosurgery.

Intermittent explosive disorder (IED) is characterized by a difficulty to resist the urge to carry out a recognized harmful behavior. The central symptom is aggressiveness, expressed in isolated episodes. Executive function impairments are habitually found in impulse control disorders. Neuropsychology of impulsivity is related to dysfunctions in the orbito-frontal cortex, dorsolateral cortex and anterior-cingulated regions, being consequently involved in cognitive mechanisms of inhibition. Lesions in those areas are common in IED. In the most severe cases of IED, surgical procedures are required for treatment. In this study, we examined JML; a patient suffering from a severe case of IED. He experienced frequent episodes of auto and heteroaggression and multiple psychiatric admissions, and thus stereotactic surgery was the recommended treatment. The procedure consisted of an electrode situated lateral to the lateral ventricle, targeting the projections between frontal and subcortical affected regions. We aimed to study the neuropsychological functioning of JML, before and after electrode implantation. Our results suggested that surgery in IED improves cognitive performance at some levels. JML significantly improved his cognitive flexibility, measured with WCST, and alternate attention assessed with CPT and TMT-B tests, after electrode implantation. Cognitive flexibility deficits may be also related to increased aggressiveness. Therefore, improvements at this level may involve a reduction of impulsivity and aggressive behavior.

The Modulation of the Startle Reflex as Predictor of Alcohol Use Disorders in a Sample of Heavy Drinkers: A 4-Year Follow-Up Study

BACKGROUND Previous studies demonstrated that patients with alcohol use disorders (AUDs) show altered startle reflex responses to alcohol-related stimuli. However, there is little information about the role of these altered responses in the development of AUDs. This study examined the startle reflex response to different visual stimuli and the role of these patterns in the development of AUDs in a 4-year follow-up. METHODS Two hundred and thirty-nine (nondependent) heavy-drinking participants were selected. In the baseline period, the startle reflex responses to alcohol-related, aversive, appetitive, and neutral pictures were assessed. Startle reflex responses to these pictures were used as predictive variables. Status drinking (alcohol dependence and nondependence) assessed at 4-year follow-up was used as outcome measure. RESULTS At the 4-year follow-up assessment, 46% of participants fulfilled DSM-IV alcohol abuse or dependence criteria. Alcohol dependence status was predicted by an attenuated startle reflex response to alcohol-related and aversive pictures. CONCLUSIONS This study revealed that an attenuated modulation of startle reflex response to alcohol-related and aversive stimuli could be used as a clinical marker to predict the development of AUDs in participants with previous alcohol consumption.