In the context of the discovery of the cerebral ligand for the cannabis receptor, and the elucidation of its genetic sequence, we discuss the psychomimetic properties of Cannabis sativa, and explore the relationship between cannabis intoxication and mood. We suggest that renewed study of acute cannabis encephalopathy would be rewarding not only in deepening our understanding of consciousness in healthy adults, but also in helping us to understand the perceptual world of the child, the elderly, and some of our patients.

Instruments developed to measure anhedonia are reviewed and their psychometric properties and conceptual framework discussed. Most instruments were designed considering anhedonia to be a symptom either of schizophrenia or of depression. Only the Physical and Social Anhedonia Scales of Chapman et al, designed to measure a lifelong pleasure deficiency, considered to be related to schizophrenia, and, to a lesser extent, the Pleasure Scale of Fawcett et al, designed to evaluate a state dependent deficit, considered to identify a subtype of depression, have been psychometrically extensively investigated. Since we were interested in studying anhedonia in depression, we made a Dutch translation of the Fawcett-Clark Pleasure Scale and report here on the psychometric properties of this translated version. Using the Rasch model for testing the homogeneity and transferability of the scale, we demonstrated that the original scale did not fit the model. A subscale of 14 items was constructed which did.

The aim of this study was to assess the effects of anxiety on attentional performance with neutral stimuli. It was set up as follows: a fourfold comparison was made of trait anxiety and state anxiety. Sixty-two undergraduate students were included in the study, and four groups of subjects were set up by a median split of the scores obtained on the Spielberger Trait and State Anxiety Inventory (STAI): high trait-high state (N = 18); high trait-low state (N = 11); low trait-low state (N = 23); low trait-high state (N = 10). A computerized battery of neuropsychological tests, the ACE battery, was administered to provide a multidimensional assessment of attention. The ACE battery comprises five tests which assess the following aspects of attention: ability to monitor a routine task; temporal preparation; visual detection; memory span; visual spatial attention and memory. High state anxious subjects displayed impairment in executive functions, manifested by a significantly higher level of motor preparation in a simple reaction time (RT) task and a speed accuracy trade-off in a divided attention task; high trait anxious subjects performed significantly better on the visual detection task. No trait × state interaction was found. It was concluded that high state anxiety is associated with psychomotor alertness and high trait anxiety with perceptual alertness. These two dimensions of psychometric anxiety seem to have effects on attention that are independent of one another and which should be analysed separately in the future.

The use of benzodiazepines seems to be associated with a deficit in the levels of arousal and attention during vigil. A number of studies have found residual effects a few hours after the intake of these drugs. This paper assesses the effects of a single dose of 10 mg diazepam on self-informed arousal (as evaluated with the Stanford Sleepiness Scale) and sustained attention (as evaluated with the Toulouse Piéron test) the morning after oral intake (11 hours later). Potential differences in the residual effects of benzodiazepines on men and women were also examined. A sample of 42 healthy young university students (21 female, 21 male) was exposed to three counterbalanced experimental conditions (control, placebo, diazepam). Diazepam only caused a reduction in arousal in women, and this deficit was similar to that caused by the intake of a placebo.

Over the past 15 years, researchers have shown an increasing interest in using event-related potentials (ERPs) to study depression. These studies generally fall into four classes: 1), ERPs as a means of detecting depression; 2), ERPs as a tool for distinguishing subtypes of depression; 3), ERPs as a measure of pharmacological effectiveness; 4), ERPs as indicators of defective cognitive operations in depressed subjects. Results from these heterogeneous approaches are often inconsistent and disappointing. Although some ERP components often show increased latencies and diminished amplitudes, these changes seem to reflect principally a variety of non-specific disorders affecting a wide range of cognitive functions rather than a precise and consistent deficit of a particular function. These disappointing results seem to be attributable to methodological problems (heterogeneous patient populations, disproportionate use of the odd-ball paradigm), and do not necessarily call into question the value of studying the ERPs. Furthermore, recent advances in ERP methodology have opened up new perspectives for ERP use in psychopathology.

The results of a cross-sectional study on N = 212 elderly in- and outpatients are presented including sociodemographic data, physical findings, CAT-scan and EEG, as well as psychological tests for cognitive performance and affective symptoms. Forty-one percent of the patients showed mild and 13% severe cognitive deficits. Depression was diagnosed in 23% of the severely impaired and in 16% of the cognitively mildly impaired or unimpaired patients. Statistical analysis revealed that increasing age, female sex and low premorbid intellectual level were significantly associated with loss of cognitive function. Dementia and depression were not significantly associated with each other. The only risk factor for depression was a history of affective illness, but not cognitive deficits or social situation. CAT-scan and EEG were abnormal in 50% of the patients; however, this did not correlate with cognitive impairment or the presence of depression. From this study it is concluded that depression and dementia coincide frequently in elderly patients, but that they are associated with different risk factors It is suggested that dementia and depression are treated as two distinct disease entities.

The case of fetal malformations with bilateral agenesis of the kidneys and severe cardiac defect under continuous lithium treatment during the first trimester is presented.