Miquel Sànchez-Turet

Neuropsychological functioning in a subclinical obsessive-compulsive sample

BACKGROUND Previous neuropsychological research has suggested that the study of psychometrically defined subclinical samples might be a valid approach to understand the underlying pathophysiology of obsessive-compulsive disorder (OCD). This approach has the potential benefit of overcoming some of the methodological problems linked to the use of clinical samples. METHODS A group of subclinical obsessive-compulsive (OC) subjects (n = 35), selected on the basis of their scores on the Padua Inventory, and a control group were assessed on executive functioning tasks and other neuropsychological tests which have been demonstrated to be impaired in clinical OCD patients and/or in those with several basal ganglia disorders. RESULTS Subclinical OC subjects needed significantly more moves than controls to reach the solution criteria on the Tower of Hanoi puzzle, and performance on this test was positively correlated with total score and the Checking factor of the Padua Inventory. There were no between-group differences on the other frontal lobe tests. CONCLUSIONS The results suggest that deficits in manipulating spatial information might be basic in OCD, and are congruent with the involvement of the frontostriatal circuits in the disorder.

Alcohol hangover: a critical review of explanatory factors

To describe the hangover phenomenon and briefly review its main explanatory factors.

Early effects of caffeinated and decaffeinated coffee on subjective state and gender differences

OBJECTIVES Some previous studies have demonstrated an early effect of caffeine administration on subjective state, but none of them has explored its existence after the administration of decaffeinated coffee, or the possible differences depending on the gender and circadian typology of the subjects. The aim of the present work is to investigate the early effects (10-30 min post-consumption) of a single low dose of caffeine (100 mg) and decaffeinated coffee on sleepiness, subjective activation and affect using a realistic design. The influence of gender and circadian typology is also explored. METHODS A randomized double-blind informed placebo controlled procedure was applied to 688 healthy undergraduate volunteers, mean age 22.03+/-2.21 years, 238 men and 450 women. Measures were recorded before and after beverage consumption (10, 20 and 30 min), in two experimental sessions: morning 11:00-13:00 h or afternoon 16:00-18:00 h. RESULTS Caffeine administration induced arousing effects (lesser somnolence and greater activation) in all post-consumption records, while the effects of decaffeinated drink were only apparent at 10 min. Caffeine effects were greater in men, and the decaffeinated beverage produced greater effects in women. Circadian typology only showed effects for time of day (morning/afternoon) related with rhythmic expression. CONCLUSION Future works should study more accurately the early effect of coffee beverages and the influence of gender, using other parameters which have proven to be sensitive to their administration. The effect of several caffeine doses should also be studied.

GENDER DIFFERENCES IN DIURNAL VARIATIONS OF SUBJECTIVE ACTIVATION AND MOOD

This article evaluates the influence of gender on diurnal and postlunch period variations in subjective activation and mood. This topic is not often addressed in the literature; particularly, little attention has been paid to how biological rhythms might bias research results. We studied 40 university student volunteers (20 men, 20 women) aged 18 to 23 years old (X = 20.23, SD = 1.03); they responded to questions on eight unipolar visual analog scales every hour from 08:00 to 21:00. Gender differences were observed in both diurnal and postlunch variations for scales of positive activation (alertness, vigor); sleepiness, however, was only sensitive to diurnal variation, and weariness was sensitive only to a postlunch effect. Women displayed a morning- type pattern, with their optimal moment (11:00) coming 2h earlier than for men, and their activation ratings ranged more widely. The only mood scale that showed differences related to gender was that of happiness, for which women had a higher diurnal mean, a diurnal peak 2h earlier, and a less-intense postlunch effect. Endogenous control of rhythmic pattern appears to be less intense in women, probably due to the coexistence of circamensual rhythmicity, although environmental or sociocultural influences may play a modulating role. Chronopsychological gender differences in affective states should be studied further given the implication they have for the prevention and treatment of mood disorders. (Chronobiology International, 18(3), 491–502, 2001)

A SPANISH VERSION OF THE PADUA INVENTORY: FACTOR STRUCTURE AND PSYCHOMETRIC PROPERTIES

This study reports the factorial structure and psychometric properties of a Spanish version of the Padua Inventory (PI) in a sample of 863 undergraduate students, 55 patients with Obsessive-Compulsive Disorder (OCD), and 20 patients with other anxiety disorders (OAD). A Principal Components Analysis suggested a 4-factor structure, which was comparable but not identical to that found in other versions of the PI involving non-clinical samples. The PI sub-scales showed good internal consistency, test-retest reliability, as well as convergent and discriminant validity. The “Washing” sub-scale of the PI failed to separate OCD and OAD patients, although this may have been due to small sample sizes. It is suggested that a revised version of the PI should include symptoms that are not currently represented in the scale, such as hoarding obsessions and compulsions.

Smoking effects on diurnal variations of cardiovascular parameters

Previous studies have reported that nicotine increases heart rate and blood pressure, showing a peak 10 min after intake. But most of the work has focused on the period of maximum effect on cardiovascular parameters and has been limited to morning measurements. The aim of this study is to evaluate the effects of smoking in diurnal variations of heart rate and blood pressure, when no restrictions are placed on the pattern of consumption and activity is controlled. The sample consisted of healthy subjects, 21 smokers and 21 non-smokers, from 18 to 26 years. The recordings were carried out hourly from 8:00 to 21:00 h in resting conditions. Heart rate was measured beat-to-beat for 2 min, and blood pressure was assessed by conventional electronic monitor. Smokers and non-smokers did not differ in diurnal levels of heart rate nor blood pressure when time of day was not considered. However, when time of day was taken into account, the groups differed significantly for heart rate and systolic blood pressure, while diastolic blood pressure only showed differences for post-lunch period. The influence of nicotine on the cardiovascular system of young and healthy smokers is more apparent in the diurnal variations than in the mean level of heart rate and blood pressure. The results emphasize the importance of a chronobiological approach in the study of the early stages of smoking on cardiovascular parameters.

The H1-receptor antagonist chlorpheniramine decreases the ending phase of the mismatch negativity of the human auditory event-related potentials

Auditory event-related potentials (ERPs) were recorded in 20 healthy male humans, who received either a single 4 mg dose of d-chlorpheniramine or a placebo, according to a double-blind design. Subjects were instructed to read a book and to ignore random sequences of 90% standard (1000 Hz) and 10% deviant (1100 Hz) tones, presented with stimulus-onset asynchrony (SOA) of 480 ms. Deviant tones elicited the mismatch negativity (MMN) response, which was smaller at its ending phase in the chlorpheniramine group. The auditory exogenous components (N1 and P2) were similar in both groups. Results demonstrate that the antihistamine chlorpheniramine selectively affects the automatic stimulus-change detector associated with MMN, and suggest an involvement of the histamine H1-receptor in the genesis of the MMN.

Reversibility of brain-stem evoked potential abnormalities in abstinent chronic alcoholics: One year follow-up

Brain-stem auditory evoked potentials (BAEPs) were studied in 34 chronic alcoholics who had been abstinent for 1 year, and in age- and sex-matched control subjects. The patients were examined 3 times, at 1 month, 5 months and 1 year after the start of the abstinence treatment. At 1 month of abstinence the alcoholics showed differences with respect to controls in the peak V latency (P < 0.01), and in the III-V (P < 0.01) and I-V (P < 0.01) intervals. After 1 year of abstinence a significant improvement in the V (P < 0.01), III-V (P < 0.01) and I-V (P < 0.01) parameters was recorded. The most notable development was in the 5-12 month period, with shortening in V latency (P < 0.01) and in the I-V interval (P < 0.01); in the first 5 months there was only shortening in the III-V interval (P < 0.01). This improvement was also indicated by a decrease in the number of patients with BAEP parameter abnormalities. The recovery of the functions impaired by chronic alcohol consumption after 1 year of abstinence was incomplete, although the tendency was towards normalization.

THE CUT-OFF POINT IN SUB-CLINICAL OBSESSIVE-COMPULSIVE RESEARCH

The question of which cut-off point would be more appropriate in the selection of sub-clinical obsessive-compulsive (OC) samples is an important methodological issue that has not been formally addressed, hence prompting the current study. Three groups of sub-clinical OC subjects, scoring 1, 1.5, and 2 standard deviations ( SD ) above the mean on the Padua Inventory, and a matched non-OC control group, were compared on various clinical and personality measures. As expected, the three sub-clinical groups had higher scores than the non-OC group on measures of OC symptoms (including obsessional slowness), depression, anxiety, and on personality measures of neuroticism, psychoticism, and obsessional traits. However, no significant differences were observed between the three sub-clinical groups on most measures, although the 2 SD group had higher scores on neuroticism and obsessional personality traits. It is concluded that a wide range of selection criteria can yield similar results that are interpretable within the current theoretical models of Obsessive-Compulsive Disorder (OCD). It is suggested that subjects with a diagnosis of OCD should be carefully excluded from sub-clinical studies. [A Spanish abstract follows the references.]

Influence of smoking and gender on diurnal variations of heart rate reactivity in humans.

We evaluated the influence of smoking and gender on diurnal variations of heart rate reactivity during performance of two vigilance tasks (auditory and visual) and a working memory task. Heart rate was measured hourly (08:00-21:00 h) at rest and during performance tasks in 20 smokers (ten men, ten women) and 20 non-smokers (ten men, ten women). Smoking and gender influenced reactivity only at certain times, especially at the earliest and latest hours and during the post-lunch period. Smokers displayed major post-lunch interference and a pattern of lowered stress in the second half of the day. Women showed greater reactivity at the first daily recording, although their levels later became similar to the mens and were even lower. The statement that women are myocardial hyperreactors must be further investigated, as it seems women may take longer than men to adapt to a task.