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Biomedical subjects

A Troisi

Publications and source records attributed to A Troisi.

At least 19 recordsLinked to original sources
PubMed1998

Female orgasm rate increases with male dominance in Japanese macaques.

Under specific circumstances, nonhuman primate females may experience orgasm. The occurrence of female copulatory orgasm appears to be highly variable, however, and its proximate causation is poorly understood. We investigated the proximate mechanisms that control orgasmic response in female macaques. During 238 h of observation of sexual behaviour in a large captive group of Japanese macaques, Macaca fuscata, 240 copulations were recorded involving 68 different heterosexual pairs formed by 16 males and 26 females. Female orgasmic responses were observed in 80 of 240 copulations (33%). The frequency of orgasms was not correlated with female age or dominance rank, but it was higher for copulations lasting longer and involving a higher number of mounts and pelvic thrusts. When the level of physical stimulation experienced by females during copulation was statistically controlled, the highest frequency of female orgasms was found among pairs formed by high-ranking males and low-ranking females and the lowest frequency among pairs formed by low-ranking males and high-ranking females. These findings suggest that the proximate mechanisms that control orgasmic threshold in female macaques are more responsive to social stimuli and less constrained by physiological limitations than previously thought. Copyright 1998 The Association for the Study of Animal Behaviour.

Journal Article↗
PubMed1998

Psychiatric symptoms in male cannabis users not using other illicit drugs.

AIM: To assess the prevalence of DSM-III-R axes I and II disorders and the severity of psychiatric symptoms in cannabis users who did not use other illicit drugs. DESIGN: Cross-sectional psychiatric examination of subjects with different patterns of cannabis use: cannabis dependence, abuse and occasional use. PARTICIPANTS: One hundred and thirty-three cannabis users identified through random urine testing of draftees to the Italian army and interviewed after 2-5 days of abstinence from drug use. MEASUREMENTS: The subjects completed the Beck Depression Inventory, the Spielberger State-Trait Anxiety Index and the 20-item revised Toronto Alexithymia Scale and were then interviewed with the Structured Clinical Interview for DSM-III-R. FINDINGS: The prevalence of co-morbid psychiatric disorders varied with the pattern of cannabis use: 83% of subjects with DSM-III-R cannabis dependence, 46% of those with DSM-III-R cannabis abuse and 29% of occasional users received at least one DSM-III-R psychiatric diagnosis. The severity of depressive, anxious and alexithymic symptoms increased progressively with the degree of involvement with cannabis. CONCLUSIONS: In this sample of young men, the risk of associated psychiatric disabilities varied with the pattern of cannabis use. Chronic use of cannabis was associated with a high prevalence of co-morbid psychiatric disorders.

Comorbidity↗
PubMed1998

Non-verbal behaviour deficits in schizophrenia: an ethological study of drug-free patients.

The aims of this study were (i) to define the dimensions of non-verbal behaviour which distinguish between schizophrenic patients and control subjects and (ii) to examine the relationship between patients' non-verbal behaviour and clinical symptoms. The non-verbal behaviour of 28 drug-free patients with schizophrenia according to Research Diagnostic Criteria (RDC) and 25 control subjects was videotaped during interviews and scored according to an ethological scoring system. Patients' symptoms were rated on the Scale for the Assessment of Negative Symptoms, the Scale for the Assessment of Positive Symptoms and the Brief Psychiatric Rating Scale. As a group, schizophrenic patients showed a global restriction of non-verbal expressiveness, as indicated by their lower scores on prosocial behaviour, gesture and conflict. However, some patients had normal ethological profiles. Non-verbal behaviour was largely independent of negative and positive symptoms. Deficits in non-verbal behaviour may play a role in determining or aggravating dysfunctional patterns of relating in schizophrenia. Ethological analysis provides further support for the model that conceptualizes positive symptoms, negative symptoms and disorders of social relationships as three separate dimensions of the schizophrenic syndrome.

Adult↗
PubMed1998

Prevalence differences in depression among males and females: are there evolutionary explanations?

Differences in male-female prevalence rates of depression are interpreted in evolutionary perspective. Three evolutionary hypotheses are evaluated: (a) depression represents an evolved strategy to deal with adverse social interactions, particularly among partners, (b) depression has self-preservative and manipulative features, and (c) depression is a consequence of failing to achieve biological goals. While these hypotheses are not necessarily mutually exclusive, evolutionary explanations often suffer from not specifying which hypothesis is primary and which are secondary. We argue that failing to achieve biological goals is primary and that evolved strategies and self-preservative and manipulative behaviour are secondary. Findings pointing to depression-contributing features of male-female differences, asymmetries in male-female relationships and male-female differences associated with reproduction are discussed to support our view that evolutionary explanations can adequately account for a significant percentage of the reported prevalence differences.

Adaptation, Psychological↗
PubMed1997

Patients with deficit, nondeficit, and negative symptom schizophrenia: do they differ during episodes of acute psychotic decompensation?

The aims of this study were (1) to test the hypothesis that the clinical profiles of deficit, nondeficit, and negative symptom patients are difficult to distinguish during episodes of acute psychotic decompensation; and (2) to compare these groups of schizophrenic patients in terms of sociodemographic and anamnestic variables. Patients admitted for acute psychotic decompensation were retrospectively diagnosed as having deficit (N = 18) or nondeficit (N = 40) forms of schizophrenia and their symptom profiles were evaluated cross-sectionally by using various rating scales (SAPS, SANS, and PANSS). As a whole, nondeficit patients were clearly differentiated from deficit patients by lower severity of negative symptoms. However, the subgroup (N = 24) of nondeficit patients with prominent negative symptoms that were secondary and/or nonenduring showed a symptom profile largely overlapping with that of deficit patients. Attentional impairment was the only measure distinguishing deficit and negative symptom patients. As for trait variables, deficit patients had lower education than the other two groups and, among male subjects, there was a higher percentage of left-handers in the deficit group than in the negative symptom subgroup. These results confirm the importance of diagnosing the deficit syndrome during periods of clinical stability in order to avoid the risk of misclassifying negative symptom patients into the deficit group.

Adult↗
PubMed1996

Symptom profile, Axis II comorbidity and suicidal behaviour in young males with DSM-III-R depressive illnesses.

We assessed the descriptive validity of DSM-III-R major depression (MDD), dysthymia (DD) and adjustment disorder with depressed mood (ADDM) by comparing the clinical profiles of 176 young male patients. The severity of depression increased progressively across the three diagnostic groups (ADDM < DD < MDD). Symptom presentation did not distinguish clearly between the diagnostic groups, even though somatic symptoms were more frequent among MDD patients. The prevalence of personality disorders was much higher (43%) among DD patients than among MDD (22%) and ADDM (15%) patients. The lifetime prevalence of suicide attempts differed in the three diagnostic groups (MDD 27%, DD 17%, ADDM 4%). Assessment of Axis II comorbidity and suicidal behavior can improve the diagnostic distinction between these DSM-III-R depressive illnesses.

Adjustment Disorders↗
PubMed1996

Primate displacement activities as an ethopharmacological model of anxiety.

Using a within-subject cross-over, vehicle-controlled design, we investigated the acute effects of benzodiazepine receptor ligands with different mechanisms of action on the displacement activities (scratching, self-grooming, and body shake) of seven male macaques living in social groups. Our aim was to test the discriminative validity of displacement activities as an ethopharmacological model of anxiety. Subjects were given i.m. lorazepam (0.10, 0.20, 0.25 mg/ kg) and FG 7142 (0.1, 0.3, 1.0 mg/kg). The frequency of displacement activities was decreased by the anxiolytic lorazepam and increased by the anxiogenic FG 7142 in a dose-dependent manner. Displacement activities were apparently more sensitive to anxiolytic treatment than other behavior patterns indicative of an anxiety state (i.e., visual scanning of the social environment and fear responses directed to dominant males). These results suggest that primate displacement activities are a valid ethopharmacological model of anxiety.

Aggression↗
PubMed1996

Marked decrease of plasma neuroactive steroids during alcohol withdrawal.

The neuroactive steroids allopregnanolone (ALLO) and allotet-rahydrodeoxycorticosterone (THDOC) are the most potent endogens positive modulators of gamma-aminobutyric acid (GABA) on GABAA receptors, a receptor system presumably responsible for some behavioral responses to alcohol withdrawal. In a group of nine alcoholic subjects, the levels of plasma ALLO and THDOC were markedly lower than those of control subjects during the early withdrawal phase (day 4 and 5), when anxiety and depression scores were higher. In contrast ALLO and THDOC plasma levels did not differ from those of control subjects during the late withdrawal phase when anxiety and depression scores were low. These results suggest that the decrease of neuroactive steroid biosynthesis may contribute to the withdrawal symptoms.

Adult↗
PubMed1996

Nonverbal behavior and alexithymic traits in normal subjects. Individual differences in encoding emotions.

The relationship between nonverbal behavior and emotional awareness, as measured by the Toronto Alexithymia Scale, was studied in 24 young volunteers free of medical and psychiatric disorders. Multiple regression analysis revealed that nonverbal behavior during psychiatric interview was a significant predictor of the Toronto Alexithymia Scale total score independent of situational depression and anxiety. Subjects who had difficulty identifying and describing their feelings showed a combination of poor nonverbal expressivity and frequent self-directed behavior patterns indicative of tension and anxiety. In addition, subjects with a tendency toward externally oriented thinking showed more avoidance behavior during the interview. The ethological data of this study support clinical observations, which suggest that alexithymic traits interfere with both processing of emotion and interpersonal behavior.

Adult↗
PubMed1995

Effects of fluoxetine on aggressive behavior of adult inpatients with mental retardation and epilepsy.

Nineteen mentally retarded inpatients with epilepsy and a history of current or recent aggressive behavior were treated with 20 mg of fluoxetine daily. All were concurrently taking other psychotropic medications, including carbamazepine and neuroleptics. A standardized rating scale (MOAS) was used to assess the effects of fluoxetine on aggressive behavior. There were wide individual differences in drug response. In nine patients, fluoxetine treatment was associated with increased aggression, while drug withdrawal led to a decrease to below pretreatment levels. Two hypotheses concerning the apparent association between fluoxetine and increased aggression are discussed: 1) adverse effects secondary to either drug interaction or fluoxetine overmedication; and 2) a specific serotonergically mediated effect on the regulation of aggression. This study suggests that the clinician who treats mentally retarded patients with impulsive aggressive behavior should remain aware that fluoxetine may have diverse effects on aggression that vary over time and interindividually.

Adult↗
PubMed1994

Lack of potentiation of anticonvulsant effect by fluoxetine in drug-resistant epilepsy.

To test the hypothesis that fluoxetine may be a useful adjunct to antiepileptic therapy, we treated with fluoxetine (20-40 mg/day) nine patients suffering from medically intractable epilepsy with daily seizures. Five patients remained unchanged and four worsened. Worsening was more evident at 40 mg/day. One patient improved when receiving the lower dose (20 mg/day) and worsened with the higher dose (40 mg/day). These data suggest: (1) that fluoxetine is not effective as add-on antiepileptic treatment; (2) that caution should be exerted when using fluoxetine as an antidepressive treatment in epileptic patients.

Adolescent↗
PubMed1992

Opiate receptor blockade in juvenile macaques: effect on affiliative interactions with their mothers and group companions.

The aim of this study was to test the hypothesis that, in non-human primates, the offspring-mother attachment and other social bonds within the group have in common neural mediating mechanisms involving brain opioids. The subjects were 10 juvenile macaques living in a stable social group with their mothers and other group companions. A within-subjects design, balanced for the order of drug administration (naloxone 1 mg/kg i.m. and saline), was used. In the naloxone condition, the juveniles increased their relative role in maintaining proximity with their mothers, made more grooming solicitations, and received more grooming. We found no evidence for differential effects of naloxone on the affiliative bonds the subjects had with their mothers and other group companions. The subjects' increased demands for social comfort were evenly addressed to, and responded to by, both their mothers and other group companions. This finding supports the hypothesis that, at a neural level, the endogenous opioid peptides form a common substrate for different types of social attachments in primates.

Analysis of Variance↗
PubMed1992

Evolutionary biology: a basic science for psychiatry?

Evolutionary biology has much to offer psychiatry. It distinguishes between ultimate and proximate explanations of behavior and addresses the functional significance of behavior. Subtheories, frequently voiced misconceptions, specific applications, testable hypotheses and limitations of evolutionary theory are reviewed. An evolutionary perspective is likely to improve understanding of psychopathology, refocus some clinical research, influence treatment and help integrate seemingly unrelated findings and theoretical explanations.

Behavior↗