Apomorphine effects on episodic memory in young healthy volunteers.

RATIONALE: Dopamine (DA) modulates working memory. However, the relation between DA systems and episodic (declarative) memory is less established. Frontal lobe DA function may be involved. We were interested in assessing whether apomorphine (Apo), a drug used extensively in clinical research as a probe of DA function, has an effect on episodic memory test performance in healthy volunteers. OBJECTIVE: To investigate the effect of a presynaptic dose of Apo on episodic memory tests and on other tests thought to be sensitive to frontal lobe functions. METHODS: Twenty healthy subjects were treated with Apo HCl (5 microg/kg sc) or placebo (10 subjects/group) in a randomized, double blind parallel group design and performance on a battery of cognitive tests was assessed. RESULTS: Apomorphine significantly impaired performance on tests of source recognition (d.f.=19, p=0.05) and item recognition memory (d.f.=19, p<0.05), and memory interference (d.f.=19, p<0.010). No significant change was found on other tests (Go/no-Go Test, Categorized Words, Stroop, Trail Making Test, and verbal fluency). CONCLUSION: Findings in this small sample of subjects suggest that dopaminergic transmission affects episodic memory functions.

Response of the HPA-axis to alcohol and stress as a function of alcohol dependence and family history of alcoholism.

Dysfunction of the hypothalamic-pituitary-adrenal (HPA)-axis has been observed in chronic alcoholics and in non-alcoholic sons of alcoholic parents, while genetic and environmental factors, such as stress, may play a significant role in the development of alcoholism. The present study was designed to investigate the response of the HPA-axis to alcohol and stress as a function of family history of alcoholism and chronic alcohol abuse. We determined changes in plasma adrenal corticotrophin (ACTH) and cortisol concentrations in response to a placebo or an alcohol (0.50g ethanol/kg body wt) drink and to a stress task performed 30 min following ingestion of either the placebo or the alcohol drink in social and heavy drinkers with [high risk (HR)] and without [low risk (LR)] a family history of alcoholism. Thus, four groups of healthy male individuals, low risk with no alcohol-dependence diagnosis (LRNAD), high risk with no alcohol-dependence diagnosis (HRNAD), low-risk alcohol dependent (LRAD) and high-risk alcohol dependent (HRAD), participated in the four experimental sessions given in random order. Basal plasma ACTH levels of LRNAD participants were higher from those of the other three groups of participants. Basal plasma cortisol levels of HRAD participants were higher from those of LRNAD and HRNAD but not of LRAD participants. The stress-induced increases of plasma ACTH and cortisol concentrations were more pronounced in LRNAD participants. The alcohol drink prevented the stress-induced increases in plasma ACTH and cortisol of all groups of participants. The self-ratings of anxiety were attenuated in LRNAD and LRAD participants in the alcohol only session and in HRNAD and HRAD participants in the alcohol plus stress session. In conclusion, there are differences in the activity of the HPA-axis as a function of family history and alcohol dependence, while the effect of an alcohol drink on the self-rating of anxiety may be influenced by both family history and stress.

Levomepromazine versus chlorpromazine in treatment-resistant schizophrenia: a double-blind randomized trial.

OBJECTIVE: We compared the effect of levomepromazine (LMP) with chlorpromazine (CPZ) in treatment-resistant schizophrenia (TRS). METHODS: We carried out a double-blind, parallel group study (n = 19/arm) with balanced randomization in blocks of 4 and stratification by sex. Subjects entered a 30-week trial, of which phases I-III were open: phase I (wk 0-6) baseline; phase II (wk 7-9) stepwise transition to haloperidol (HAL), 30 mg/d, plus benztropine (BT), 4 mg/d; phase III (wk 10-15) HAL, 40-60 mg/d, plus BT, 4-6 mg/d; phase IV (wk 16-20) stepwise transition to LMP or CPZ (500 mg/d) following randomization; phase V (wk 21-28) stepwise increase of LMP or CPZ (600-1000 mg/d, dose reduction permitted) to establish optimum dose; and phase VI (wk 29-30) optimized dose maintained. Criteria for TRS were based on those established by Kane et al in 1988. The criterion for a response to treatment was a reduction of 25% or more in total Brief Psychiatric Rating Scale score. RESULTS: Both LMP (p = 0.007) and CPZ (p = 0.030) improved TRS relative to baseline. Although there was no significant difference between the 2 groups in treatment response at study end point, hierarchical linear modelling of longitudinal outcome revealed a significant (p = 0.006) advantage of LMP over CPZ for the BPRS total score. Ten of 19 participants on LMP and 8 of 19 on CPZ met the criterion for treatment response, and 9 of the 18 responders did so on 200-700 mg/d phenothiazine. The mean dose of responders was 710 (standard deviation [SD] 265) mg/d (LMP) and 722 (SD 272) mg/d (CPZ). Akathisia was associated with a nonresponse to phenothiazines (p = 0.010). BPRS scores increased significantly on HAL (p = 0.006). Two of 19 participants on LMP and 5 of 19 on CPZ withdrew early from the study. CONCLUSION: LMP and CPZ may be useful in the management of TRS. A modest advantage of LMP compared with CPZ was seen in longitudinal analysis. High doses of neuroleptics may contribute to TRS; reduction of neuroleptics to modest or moderate doses should be considered before categorizing a patient as treatment resistant.

Differences in the peripheral levels of beta-endorphin in response to alcohol and stress as a function of alcohol dependence and family history of alcoholism.

BACKGROUND: Evidence indicates that both genetic and environmental factors, such as stress, may play an important role for the development of alcoholism, while beta-endorphin may be implicated in the control of alcohol consumption. The objective of the present studies was to test the hypothesis that there are differences in the response of the pituitary beta-endorphin system to stress as a function of family history of alcoholism and alcohol dependence. METHODS: The response of the pituitary beta-endorphin to a placebo or an alcohol (0.50 g ethanol/kg) drink and to a stress task performed 30 min following ingestion of either the placebo or the alcohol drink was measured in social and heavy drinkers with [high risk (HR)] and without [low risk (LR)] a family history of alcoholism. Thus, each subject participated in 4 experimental sessions given on different days in a randomized order. Four groups of subjects were investigated: 1) low risk nonalcoholics (LRNA); 2) high risk nonalcoholics (HRNA), 3) low risk alcoholics (LRA); and 4) high risk alcoholics (HRA). Plasma beta-endorphin was estimated prior to and for 3.5 hr post-stress. Changes in the concentration of plasma beta-endorphin following ingestion of either the placebo or alcohol drink without performance of the stress task served as controls to compare the stress-induced changes. RESULTS: Basal plasma beta-endorphin levels were higher in LRNA than LRA, HRNA and HRA participants, while basal plasma beta-endorphin levels were higher in LRA than those in HRNA and HRA participants. Furthermore, there was no significant difference in the plasma beta-endorphin levels between HRNA and HRA participants. Stress, induced a significant increase in plasma beta-endorphin concentration in all four groups of participants. However, the stress-induced increase in plasma beta-endorphin levels was more pronounced in LRNA than HRNA, LRA and HRA participants. Thus, alcohol dependence decreased the basal plasma beta-endorphin levels in LR only, as well as the stress induced increase in plasma beta-endorphin levels of participants without, but not of those with, a family history of alcoholism. Alcohol prior to stress attenuated the stress-induced increase in plasma beta-endorphin levels of all four groups of participants. CONCLUSIONS: The present data indicates that there are differences in both, the basal plasma beta-endorphin levels as well as the response of the pituitary beta-endorphin to stress as a function of family history of alcoholism and alcohol dependence. Thus, in HR individuals a dysfunction in the activity of the pituitary beta-endorphin system predates the development of alcoholism, while in LR individuals it develops following alcohol dependence. Furthermore, alcohol dependence did not alter the alcohol-induced attenuation of beta-endorphin response to stress.

Levels and circadian rhythmicity of plasma ACTH, cortisol, and beta-endorphin as a function of family history of alcoholism.

RATIONALE: Individuals with a family history of alcoholism may present a dysfunction in the activity of the hypothalamic-pituitary-adrenal (HPA) axis that predates the development of alcoholism. OBJECTIVE: The present study investigated the hypothesis that this HPA-axis dysfunction is associated with alterations in the pattern of the circadian (24 h) secretions of adrenal corticotropic hormone (ACTH), cortisol, and beta-endorphin. METHODS: Men with [high risk (HR)] or without [low risk (LR)] family history of alcoholism participated in the study. Blood samples were drawn every 30 min for 24 h for estimation of the plasma hormone levels. Participants ingested meals at predetermined intervals and filled out mood questionnaires prior to the placement of the catheter and 1 h after each meal. RESULTS: The circadian peaks for beta-endorphin, ACTH, and cortisol occurred between 0800 and 0830 hours in both LR and HR participants. The plasma ACTH and beta-endorphin concentrations were lower in HR than LR participants, while the plasma cortisol concentrations were similar between HR and LR participants. For each hormone, the total 24-h secretion was estimated from the area under the 24-h time-concentration curve (AUC). For ACTH and beta-endorphin, but not the cortisol, AUC were lower in HR than LR participants. LR participants reported being more nervous than HR participants. For the LR participants, but not HR participants, the initial mood ratings of "nervous" were positively correlated with the initial plasma cortisol and beta-endorphin concentrations as well as with the cortisol and beta-endorphin AUC. CONCLUSIONS: HR participants presented lower plasma concentrations as well as lower AUC for beta-endorphin and ACTH but not for cortisol. This suggests a dysfunction of the HPA-axis in HR participants that predates the development of alcoholism and a dissociation between plasma ACTH and cortisol levels as a function of family history of alcoholism.

Nicotine and behavioral markers of risk for schizophrenia: a double-blind, placebo-controlled, cross-over study.

We investigated the effect of nicotine on three behavioral markers of risk for schizophrenia: sustained attention (using the Continuous Performance Task (CPT)), antisaccade performance, and smooth pursuit. Smooth pursuit was investigated in two conditions, one in which attention was enhanced (monitoring target changes) and one in which attention was not enhanced (no monitoring). Patients with schizophrenia (n = 15) and controls (n = 14) were given a 14-mg nicotine patch in a double-blind, placebo-controlled, crossover design and plasma nicotine concentrations were monitored. Nicotine concentrations were similar in both groups. A Group x Drug interaction (p <.02) on CPT hits indicated that nicotine improved sustained attention in patients but not in controls. Nicotine significantly decreased antisaccade errors (p <.01) in both groups. A Drug x Monitoring condition interaction (p <.01) on pursuit gain indicated that nicotine significantly increased pursuit gain in the no-monitoring condition in patients and controls equally, but did not improve pursuit in the monitoring condition. Thus, improvement in pursuit may have been mediated via an effect on attention rather than by an effect on oculomotor function per se. In patients, the magnitude of improvement in attention on nicotine was correlated with the improvement on eye movement tasks. Thus, nicotine improves performance on both attention and oculomotor markers of risk for schizophrenia, possibly via common mechanisms.

Response of the hypothalamic-pituitary-adrenal axis to stress in the absence and presence of ethanol in subjects at high and low risk of alcoholism.

Both genetic and environmental factors, such as stress, are important in determining alcohol consumption. Furthermore, both stress and alcohol influence the activity of the hypothalamic-pituitary-adrenal (HPA)-axis. Thus, the present studies investigated the response of the HPA axis to stress and the effect of ethanol on the stress response, in subjects at high (HR) and low (LR) risk of alcoholism as determined from their family history. Twenty HR and 20 LR subjects performed a stress-inducing task 30 min following the ingestion of either a placebo drink or a low dose of ethanol. The levels of plasma adrenal corticotropic hormone (ACTH) and cortisol were measured prior to and for four hours following initiation of the treatment. Changes with time in the plasma hormone levels following ingestion of either a placebo or an ethanol drink, without the performance of the stress task, served as controls to compare the stress-induced changes. Neither the placebo nor the ethanol drink altered the plasma ACTH and cortisol concentrations. High risk subjects presented lower basal ACTH, but not cortisol, levels and a lower stress-induced increase in plasma ACTH concentration than LR subjects. Furthermore, the HR subjects presented a delayed post-stress recovery of the plasma ACTH and cortisol levels. Ethanol consumption prior to the stress task attenuated (ACTH) or abolished (cortisol) the stress-induced increase in the plasma hormone concentrations of both LR and HR subjects. Thus, there are quantitative differences on the response of the HPA-axis to stress between HR and LR subjects, while ingestion of low amounts of ethanol prior to the performance of the stress task had a similar effect on HR and LR individuals.

Differences in the responses of the pituitary beta-endorphin and cardiovascular system to ethanol and stress as a function of family history.

BACKGROUND: Genetic and environmental factors, such as stress, are important for the initiation and maintenance of heavy drinking, whereas beta-endorphin may be important in controlling alcohol consumption. These studies investigated the response of pituitary beta-endorphin to stress and the effect of alcohol on the stress response in subjects at low (LR) and high (HR) risk of alcoholism, as determined from their family history. METHODS: Twenty LR and 20 HR subjects were exposed to stress 30 min after ingestion of either a placebo or an alcohol drink. Plasma beta-endorphin was measured before and for 4 hr after the drink. Changes in the concentration of plasma beta-endorphin after ingestion of the placebo or alcohol drink alone served as controls to compare the stress-induced changes. Pulse and diastolic and systolic blood pressure were also measured. RESULTS: HR subjects presented higher baseline values of pulse and systolic blood pressure and lower plasma beta-endorphin than LR subjects. Stress induced a small increase in cardiovascular activity, whereas alcohol induced a stronger stimulation. Alcohol before stress did not prevent the stress-induced increase in cardiovascular activity. Stress, but not alcohol, increased the plasma beta-endorphin concentration. LR subjects presented a higher stress-induced increase in plasma beta-endorphin and a faster recovery than HR subjects. Alcohol before stress attenuated the stress-induced increase in plasma beta-endorphin in both LR and HR subjects. This attenuation was stronger in LR subjects. CONCLUSIONS: Thus, there are differences in the response of beta-endorphin to stress and the effect of ethanol on stress responses as a function of a family history of alcoholism.