P. Castrogiovanni

Psychological stress and body temperature changes in humans.

We investigated the possible changes in body temperature, heart frequency, and blood pressure in 22 residents sitting for the yearly exam at the Specialty School of Psychiatry at Pisa University. All subjects were then evaluated 2 or 3 weeks later, in calm situations. In a subgroup, a specific plasmatic diazepam binding inhibitor (BBIA), previously described, was also measured. The results showed that all subjects underwent significant stress-related changes in the parameters studied, which suggest the involvement of different mechanisms in preexam stress.

Pain threshold is reduced in depression.

Pain and depression may share common neurochemical substrates, therefore the study of pain sensation in depression might be valuable in the investigation of the pathophysiology of depression itself. In order to investigate the sensation of pain in depression, we measured pain threshold and sensory threshold by means of a dental tester, comparing a group of depressed patients with healthy volunteers. The results showed the presence of a higher sensory threshold and pain threshold in patients than in controls. This may be related to a hyperfunction of the opiate system, which in turn might be primary or secondary to a decreased modulatory function of other neurotransmitters, in particular of serotonin, whose abnormalities in depressive states are well-documented.

Aggressive Behaviour and Hostility in Depression: Clinical Aspects

Aggressiveness has been studied chiefly in animals by pharmacologists and ethologists and in man by psychologists and sociologists. Yet, it is also of great interest in psychiatry. Aggressiveness, in terms of violence, has received much attention as has aggressive behaviour in which violent actions are only an aspect.

Methadone dosages and therapeutic compliance during a methadone maintenance program

In 97 heroin addicts in a methadone maintenance treatment program (MMTP) with social services, urine screening for opioid metabolites identified groups with different treatment compliance. The positive correlation between compliance and methadone dosage confirms that MMTPs are effective in rehabilitating patients when adequate dosage, i.e., capable of preventing relapse, is used.

Seasonal serotonin uptake changes in healthy subjects

Platelet 5-hydroxytryptamine (5HT) uptake was measured in 12 healthy subjects in the spring, summer, and late autumn. The uptake was performed according to the method of Arora and Meltzer (1981). The maximal velocity of 5HT uptake was higher in the spring and in summer than in the autumn. In addition, a significant negative correlation between the Michaelis constant and the photoperiod was observed in spring. These findings seem to indicate the possible evidence of physiological season-related changes of platelet 5HT uptake that may be linked to the photoperiod.

Comparison of Aggressive Behavior between Men and Women in Sport

A group of 33 sportsmen and 43 sportswomen and a group of 488 subjects (less than 30 years old) selected from a sample of 816 subjects representative of the general Italian population were compared using the factor scores and total scores on the Italian version of the Buss and Durkee questionnaire. Analysis suggests a positive correlation between aggressiveness and sport and are compatible with the hypothesis that sporting activities serve as a means of controlling aggressiveness of women and help the individual psychosocial development of men. The decision to practice sports would seem to be connected with the needs to conform to cultural stereotypes, which portray the man as aggressive and the woman as gentle and submissive.

Age-related differences in human platelet 5-HT uptake.

SummaryPlatelet 5-hydroxytryptamine (5-HT) uptake was measured in a group of young healthy volunteers and a group of aged healthy volunteers. Our results show a significant increase in the maximal velocity of uptake (Vmax) in the platelets of aged subjects. This could result in a decreased concentration of extracellular 5-HT in old age. Such reduced levels of 5-HT, if they occurred at 5-HT synapses in the brain, could result in susceptibility to the development of neurological or psychiatric illness.

Imipramine Binding as a Predictor of Fluoxetine Response in Depressed Patients

We evaluated platelet 3H-imipramine (3H-IMI) binding parameters (Bmax and Kd) at baseline (t0) and 2 months after (t1) treatment with fluoxetine in a group of outpatients affected by a major depressive episode, according to DSM-IIIR criteria. The possible relationships between biological parameters and the Hamilton Rating Scale for Depression (HRSD) total score were examined. The results confirmed previous reports that depressed patients possessed a lower density (Bmax) of platelet 3H-IMI binding sites than healthy controls, but the Bmax tended to decrease with fluoxetine. In addition, we observed a negative correlation between Bmax values at t0 and the HRSD total scores at t1 indicating that the patients who responded better to fluoxetine were those with a lower Bmax at t0. Future studies will substantiate this preliminary observation on the possible usefulness of platelet 3H-IMI binding as a predictor of pharmacological response.

Interaction between the serotonin and dopamine systems in humans: preliminary findings

The availability of peripheral tools, such as platelet [3H]-imipramine binding and electroretinogram b-wave amplitude, for investigating serotonin and dopamine systems respectively, prompted us to explore the possible relationships between these two systems in a group of 8 healthy drug-free volunteers. The results showed a significant correlation between the peripheral parameters of serotonin and dopamine systems and underline the importance of studying different neurotransmitters at the same time in humans.

Platelet Serotonergic Markers and Aggressive Behaviour in Healthy Subjects

The availability of peripheral markers of the serotonergic system, which appears to play a major role in aggressive behaviour, prompted us to investigate in healthy subjects the possible correlations between platelet 3H-imipramine (3H-IMI) binding or mono-amine-oxidase (MAO) activity and aggression as measured by the Italian version (QTA) of the Buss and Durkee Inventory. The results showed the presence of significant and positive correlations between MAO activity and QTA total scores and the scales of negativism and verbal aggression, and no correlation between 3H-IMI binding parameters and QTA. These findings seem to suggest that perhaps the MAO activity is more linked to the dimension of aggression than is IMI binding.