Rosa Jurado

Laboratory Paradigms of Impulsivity and Alcohol Dependence: A Review

Impulsivity can be defined as choosing a smaller, immediate reward over a larger, delayed reward. From this perspective, addictive behaviors such as substance abuse and pathological gambling reflect a series of impulsive choices. However, impulsivity is not a homogeneous construct. Laboratory measures of impulsivity reflect two types of processes. The first is related to behavioral inhibition and refers to an individual’s ability to appropriately inhibit thoughts or actions. The second is the delay of reward dimension, namely the degree to which immediate (rewarding) consequences have more control over an individual’s behavior than consequences that are delayed. In this review, we describe how alcohol is associated with significant impairments in these paradigms. We also suggest that they may have a role in the development of alcohol dependence. These results are in agreement with a model in which delay of gratification might be a marker for early use and/or abuse of alcohol, whereas impairment in behavioral inhibition might be a marker for maintained use in time and, therefore, for progression towards alcohol dependence.

Variables involved in the cue modulation of the startle reflex in alcohol-dependent patients.

Cue modulation of the startle reflex is a paradigm that has been used to understand the emotional mechanisms involved in alcohol dependence. Attenuation of the startle reflex has been demonstrated when alcohol‐dependent subjects are exposed to alcohol‐related stimuli. However, the role of clinical variables on the magnitude of this response is unknown. The objective of this study was to determine the relationship between a number of clinical variables—severity of alcoholism, family history of alcoholism (FHA+), personality traits related to the sensitivity to reward—and the startle reflex response when subjects with alcohol dependence were viewing alcohol‐related cues. After detoxification, 98 participants completed self‐report instruments and had eye blink electromyograms measured to acoustic startle probes [100‐millisecond burst of white noise at 95 dB(A)] while viewing alcohol‐related pictures, and standardised appetitive, aversive and neutral control scenes. Ninety‐eight healthy controls were also assessed with the same instruments. There were significant differences on alcohol‐startle magnitude between patients and controls. Comparisons by gender showed that women perceived alcohol cues and appetitive cues more appetitive than men. Male and female patients showed more appetitive responses to alcohol cues when compared with their respective controls. Our patients showed an appetitive effect of alcohol cues that was positively related to severity of alcohol dependence, sensitivity to reward and a FHA+. The data confirmed that the pattern of the modulation of the acoustic startle reflex reveals appetitive effects of the alcohol cues and extended it to a variety of clinical variables.

Factor structure and psychometric properties of the TFEQ in morbid obese patients, candidates to bariatric surgery

BACKGROUND To analyze the factor structure and psychometric properties of the TFEQ in a morbid obese Spanish sample of bariatric surgery candidates. METHOD Multi-trait/ multi-item analyses and alpha coefficients were conducted to test the convergent /discriminant validity and the internal consistency reliability. Principal components analyses (varimax) were used to explore the factor structure. Sub-group factor analyses by gender, age and body mass index (BMI) were conducted to identify unstable items. RESULTS The internal structure of the original TFEQ factors was unsatisfactory, especially the Disinhibition Scale. Most Disinhibition and Hunger items were grouped on one factor labeled “Dysregulation Eating”. Cognitive Restraint was split into two factors. The first one, related to the behavioral component of Restraint, labeled “Restrained Behaviour” and the second one related to weight and eating concerns called “Predisposition to Restraint”. CONCLUSIONS The original factor structure of the TFEQ was not replicated. A revised 23-item instrument, representing the three new derived factors is offered as a valid screening instrument for severely obese patients.

Neuropsychological Models of Depression

Depression is a psychiatric disorder with high prevalence in Mental Health Centers and in the general population. In recent decades there has been a growing interest in applying models of emotion and motivation to the study of affective disorders. Two of the most relevant models in this field have investigated the relationship between depression and positive and negative affects and also the association between emotional functioning and cortical brain asymmetries in subjects with depression.

Correlation Between Clinical and Drinking Variables, and Psychophysiological Processes Involved in Alcohol Dependence

Background Alcoholics show attentional bias when viewing alcohol-related pictures, a low magnitude of the startle response when viewing alcohol-related cues, and a poor inhibitory control. However, it has not been studied which clinical and drinking variables modulate these paradigms. Objectives To explore which clinical and drinking variables modulate attentional bias, affective modulation of the startle reflex and behavioural inhibition in alcoholics. Methods 127 alcoholics were tested with 3 psychophysiological tasks: the dot probe task (attentional bias), the startle response when viewing alcohol cues (affective modulation of the startle reflex) and the Stop Signal Task-Modified (behavioural inhibition). Clinical variables were evaluated using the Barrat Scale (BS), the Hamilton Anxiety Scale (HAS) and the Hamilton depression Scale (HDS). Drinking variables were assessed with the Timeline follow back (TLF). Results Attentional bias correlated with the number of drinking days, mean intake of alcohol and score of the HDS. Affective modulation of the startle reflex correlated with mean intake of alcohol, scores of the HDS and the BS. Behavioural inhibition correlated with scores of the HDS, the HAS and the BS. Conclusions Psychophysiological tasks correlated with drinking variables (mean intake of alcohol and the number of drinking days) and clinical variables (impulsivity, anxiety and depression). Clinicians should take these variables into account when treating alcoholics because they can be controlled with appropriate pharmacological treatment and it is well known that attentional bias, affective modulation of the startle reflex and behavioural inhibition are implicated in maintaining alcohol consumption and increasing the risk of relapse.

Startle-Response Based Tasks and Laboratory Measures of Impulsivity in Abstinent Alcoholic Patients

AIMS It is well known that impulsivity is a risk factor for the development of Addictive Disorders, and more specifically Alcohol Use Disorders (AUD). Recently, the Startle-Response Based Tasks (SRBT) and its different forms of plasticity have been found to be impaired in the alcoholic population. This is the first study to explore the correlation between impulsivity laboratory tasks and the SRBT test, in order to determine whether impulsivity and startle response (SR) could be related and in turn, explain their association with Alcohol Dependence (AD). METHODS SUBJECTS 40 men, who met DSM-IV criteria for AD and had been abstinent for at least one month. Impulsivity was assessed using three laboratory tests: Continuous Performance Test (CPT), Stop-Signal Task (SST) and Differential Reinforcement for Low-Rate Responding (DRL6). Patients also underwent the SR test. They were compared to 40 matched controls. RESULTS Impulsivity laboratory measures tasks (SST and commissions of the CPT) correlated positively with the magnitude of SR (P < 0.05) and with habituation (P < 0.05). Scores on DRL6 correlated negatively with the magnitude of SR (P < 0.05). This was not found in the control group. CONCLUSIONS The fact that impulsivity laboratory measures and the SR are correlated in patients but not in controls, could imply the existence of a common link for these two measures in alcoholic patients. Our findings support the hypothesis of the existence of two different vulnerability pathways for the development of AUD: anxiety and disinhibitory behaviour.

EPA-0843 - Relationship between psychophysiological processes involved in alcohol dependence

Background Current data suggest that at least three psychophysiological paradigms are involved in Alcohol Dependence: attentional bias; affective modulation of the startle reflex and behavioural inhibition. These three paradigms have not been studied together in a sample of alcohol dependent subjects. Objectives To show that the performance on these three psychophysiological processes allows discriminating alcohol dependent subjects (with different severity) from healthy controls. Methods 59 alcohol dependent subjects were assessed with the following three psychophysiological tasks: The dot probe task (which assesses attentional bias), the startle response when viewing alcohol cues (which evaluates affective modulation of the startle reflex), and the Modified- Stop Signal-Task (which measures behavioral inhibition). The Severity of Alcohol Dependence Scale (SAD) was used for grouping patients based on their dependence severity. 52 healthy subjects were assessed as the control group. Results All three paradigms correctly discriminated between patients and controls. Patients were divided into three subgroups according to their scores on the SAD (mild, moderate and severe dependence). The performance of the three groups in the three paradigms studied was also different. Patients with more severe dependence had more attentional bias for alcohol cues, exhibited lower magnitudes of startle response when viewing alcohol cues, and showed lower capacity to inhibit their behaviour when words related to alcohol were being seen. Conclusions Subjects with alcohol dependence showed different psychophysiological response patterns compared to controls in the three paradigms studied. These response patterns seem to be associated with the severity of dependence, and they could be used to determine the outcome of the treatment in patients with alcohol dependence.