A. Feline

Time course of prefrontal lobe dysfunction in severely depressed in-patients: a longitudinal neuropsychological study

The Stroop Colour-Word Test (SCWT) and the Verbal Fluency Test (VFT), two tests that have been suggested to be particularly sensitive to prefrontal dysfunction, were administered to 23 severely depressed in-patients. Both tests were impaired in patients at inclusion, but only verbal fluency normalized with successful treatment of depression. VFT impairment is consistent with the hypothesis of a left prefrontal cortex dysfunction in depression. Moreover, the persistence of an impaired performance on SCWT in patients at discharge suggests that a selective attention deficit may persist in patients beyond a clear clinical improvement.

Frontal dysfunction in neurologically normal chronic alcoholic subjects: Metabolic and neuropsychological findings.

BACKGROUND Neuropsychological and imaging studies suggest that frontal dysfunction may occur in apparently normal chronic alcoholic subjects. METHODS To investigate this issue further, we performed neuropsychological and fluorodeoxy-glucose-PET studies in 17 chronic alcoholics without patent neurological and psychiatric complications. RESULTS Metabolic abnormalities were found in the mediofrontal and in the left dorsolateral prefrontal cortex, but not in the orbitofrontal cortex. Neuropsychological testing revealed significantly reduced verbal fluency and impaired performance on the Stroop test. The mediofrontal hypometabolism correlated with the reduction in verbal fluency and the time necessary to perform the interference condition of the Stroop test. The left dorsolateral prefrontal hypometabolism correlated with the number of errors on the Stroop test. CONCLUSION These data indicate that circumscribed frontal dysfunctions may occur in chronic alcoholic subjects before clinically obvious neurological complications, and may account for some of the alcohol-related neuropsychological and behavioural impairments.

Presynaptic dopaminergic function in the striatum of schizophrenic patients

The dopaminergic hypothesis of schizophrenia postulates increased brain dopaminergic activity. Two previous studies reported increased 18F-DOPA uptake with positron emission tomography in schizophrenic patients (n = 5, n = 7). In the present study, striatal dopaminergic function was assessed in vivo in six untreated schizophrenics and seven control subjects, comparable for age and sex. The 18F-fluoro-L-DOPA (18F-DOPA) uptake rate constant Ki was determined in the caudate and putamen using coregistered positron emission tomography and magnetic resonance imaging. No difference between groups for mean Ki was found. The variability of the 18F-DOPA uptake values was higher in the caudate (p < 0.01) and in the putamen (p < 0.001) in schizophrenic patients than in control subjects, suggesting that schizophrenia is a disorder involving heterogeneous states of the striatal presynaptic dopaminergic function.

The cortical serotonin2 receptors studied with positron-emission tomography and [18F]-setoperone during depressive illness and antidepressant treatment with clomipramine.

BACKGROUND Changes in serotonin (5-HT)2 receptor densities were reported in depression by postmortem studies and following treatment with tricyclic antidepressants in animal studies. Here, 5-HT2 receptors were studied in vivo in depressed patients. METHODS Cortical 5-HT2 receptors were investigated prospectively using positron-emission tomography and [18F]-setoperone in 7 depressed patients, before and after at least 3 weeks of clomipramine (CMI), 150 mg daily. They were compared to 7 age-matched controls. RESULTS There was no significant difference between the untreated patients and the controls, except in the frontal region, where the [18F]-setoperone specific binding was slightly lower in patients. After CMI treatment, depression scores significantly improved and [18F]-setoperone specific binding decreased in cortical regions, suggesting receptor occupancy and/or receptor regulation, by CMI; however, no clinical score correlated with the 5-HT2 receptor measurements either in the untreated or in the treated conditions. CONCLUSIONS These data substantiate the view that tricyclic antidepressants such as clomipramine significantly interact with cortical 5-HT2 serotoninergic receptors in actual therapeutic situations.

The dissociation of explicit and implicit memory in depressed patients

Twenty-three in-patients fulfilling DSM-III-R criteria for major depressive disorder were submitted to a standard cued recall test, and to a word-stem completion test devised to assess the effect of the initial presentation without the explicit retrieval of the words being necessary. Results show that depressed patients are impaired on the cued recall task in comparison with controls matched for sex, age, and educational level. However, the two groups do not differ in the word-stem completion task. This dissociation between explicit and implicit expressions of memory disappeared when patients recovered, although they were still hospitalized and under psychotropic medication. These results are examined in the light of the distinction between effortful and automatic processes.

No serotonin 5-HT2A receptor density abnormality in the cortex of schizophrenic patients studied with PET

To investigate putative abnormalities of cortical 5-HT2A receptor density in schizophrenia, we used positron emission tomography and [18F]setoperone, a high-affinity 5-HT2A receptor radioligand, in 14 neuroleptic-free or -naive schizophrenic patients and in 15 normal controls. No significant difference between the groups was observed in the whole or regional cortical binding potential of [18F]setoperone, indicating an absence of major 5-HT2A receptor cortical density abnormalities in schizophrenics.

Context-dependent information processing in patients with schizophrenia.

Thirty schizophrenic patients fulfilling the Diagnostic and Statistical Manual of Mental Disorders IV criteria for schizophrenia and 30 control participants were shown a set of incomplete sentences, and were asked to complete them with the first word(s) that came to mind. Target sentences included an ambiguous word, the ambiguity of which was not resolved within the clause. However, completion necessarily required participants to select one specific meaning. Each target sentence was preceded by another sentence playing the role of context, which was designed to prime the less frequent meaning of the ambiguous word. The results showed that schizophrenic patients, especially those with thought disorder [on the basis of their TLC scores (Thought, Language and Communication Scale; Andreasen, N.C., 1979. Thought, language and communication disorders. Clinical assessment, definition of terms and evaluation of their reliability. Diagnostic significance. Arch. Gen. Psychiatry 39, 778-782)], used the most common meaning of the ambiguous word more frequently than controls, thus revealing a specific deficit in context use. The deficit was observed whether or not the relation between context and target sentences was made explicit. These results are in line with the cognitive models of schizophrenia that postulate a decreased ability to use context information. However, when considered in the light of prior studies (e.g., Bazin, N., Perruchet, P., 1996. Implicit and explicit memory in patients with schizophrenia. Schizophr. Res. 22, 241-248), they suggest that the deficit in processing contextual information is limited to what Baddeley (Baddeley, A.D., 1982. Domains of recollection. Psychol. Rev. 98, 708-729) called the interactive context (which affects the meaning, or the interpretation, of the target event) in contrast to the independent context (which does not interfere with the meaning-based interpretation of the target event).

Mood congruence effect in explicit and implicit memory tasks : a comparison between depressed patients, schizophrenic patients and controls

This study investigates mood congruence effect in explicit and implicit memory tasks in 23 inpatients fulfilling DSM-III-R criteria for major depressive disorder. Performances were compared to those of 15 in- or outpatients fulfilling DSM-III-R criteria for schizophrenia, and 37 normal subjects serving as euthymics controls. All subjects were submitted to a standard cued recall test and to a word stem completion test devised to assess the effect of the initial presentation without the explicit retrieval of the words being necessary. The material used for these two tasks consisted of emotionally negative and positive words. The results show a mood congruence effect in the ;;;implicit;; memory task (and not in the ;;;explicit;; memory task) only in patients who had recovered from their major depressive episode (and not in depressed patients, schizophrenic patients, or controls). These results suggest that implicit and explicit emotional information processing differ from one another in certain respects.

Dépressions avec attaques de panique: caractéristiques cliniques et prévalence en milieu hospitalier.

Seventy-three patients successively hospitalized in psychiatry and meeting the criteria of the DSM-III for diagnoses of major depressive episode with or without melancholia (n = 64), dysthymia (n = 5) or adjustment disorder with depressed mood (n = 2) were studied. Of these 73 patients, 50.7% also exhibited, at the time of their hospitalization, panic disorder as defined by the DSM-III criteria (53.4% having exhibited this disorder at some time in their life). Moreover, eight of the 73 patients (11%) exhibited, or had exhibited at some time in their life, a “sub-panic” state characterized by recurring rudimentary attacks, while five of the 73 patients (6.8%) exhibited “permanent panic anxiety” tending to fluctuation rather than paroxysm. These two forms of anxiety raise the question of the limits of panic disorder. The comparison of depressions with and without panic disorder shows an even distribution of endogenous and nonendogenous forms in both groups. Depressions with panic disorder, moreover, registered greater intensity (according to the HDRS score), a higher lever of anxiety (according to the AMDP-AT score), and a higher degree of nervousness (according to the EPI score) than depressions without panic disorder. The study of the chronology of the associations between depressions and panic disorder shows that in more than one-half of the cases these disorders began within one month of each other. In one-third of the cases, panic disorder preceded the depressive episode by more than one month. And finally, in just over 10% of the cases, panic disorder appeared more than one month after the beginning of the depressive episode.