Addictive-like behaviours to ultraviolet light among frequent indoor tanners.

BACKGROUND: Frequent, purposeful exposure to ultraviolet (UV) light may induce a compulsive desire to tan despite the negative consequences being known, suggesting a behavioural complex similar to addictive disorders. AIM: To assess the presence of addictive-like behaviours in subjects using indoor tanning salons. METHODS: Subjects (n = 100) were surveyed by two questionnaires: a modified CAGE questionnaire to assess behaviours consistent with problem tanning and a modified Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) ('substance dependence' criteria) to assess behaviours consistent with a dependence-like disorder. RESULTS: In total, 41% of subjects met criteria consistent with a 'tanning addictive disorder', and an additional 33% met criteria for problematic tanning behaviour based on the modified CAGE criteria or subthreshold criteria on the modified DSM-IV criteria. Female gender and early age of onset were associated with meeting tanning addiction criteria. CONCLUSION: A high percentage of subjects who tan frequently in indoor salons experience behaviours and consequences to their tanning consistent with other identified addictive disorders.

High correlations of norepinephrine, dopamine, and epinephrine and their major metabolite excretion rates.

We have previously reported high correlations between norepinephrine and its metabolite outputs in depressed patients. In this article, we expand this finding to healthy volunteers and alcoholic patients. Furthermore, we find similar high correlations between urinary outputs of dopamine, norepinephrine, and their major metabolites. The same is true, to a lesser degree, for epinephrine and metanephrine outputs. There are implications of these findings for psychobiological research on the monoamine systems.

Personality and cerebrospinal fluid monoamine metabolites in alcoholics and controls.

Alcoholics as a group have been consistently reported to show differences from controls on various personality inventories. Moreover, neurobiologic substrates have been postulated to underlie personality dimensions. Therefore, we compared alcoholics with controls on measures of personality and investigated relationships between measures of personality and cerebrospinal fluid monoamine metabolite concentrations. The alcoholics were significantly different from controls on many personality measurements. There were significant, negative correlations between interview-derived lifetime aggression scores and cerebrospinal fluid concentrations of both the serotonin metabolite 5-hydroxyindoleacetic acid and the dopamine metabolite homovanillic acid. However, there were no significant correlations between any cerebrospinal fluid monoamine metabolite concentrations and scores on personality inventories.

Lactate and hyperventilation substantially attenuate vagal tone in normal volunteers. A possible mechanism of panic provocation?

Many aspects of panic attacks, eg, palpitations, tremor, sweating, and an emotional sense of "fear," have been theorized to arise from sympathetic nervous system activation. However, most studies have not demonstrated clearly increased levels of catecholamines during an attack, which is contrary to this hypothesis. To explore another possible cause for the physiological changes known to occur during a panic attack, we assessed parasympathetic nervous system activity by measuring vagal tone during treatments known to produce panic symptoms: sodium lactate administration and hyperventilation. Our findings showed a marked reduction in vagal tone during both procedures. We postulate that withdrawal of parasympathetic activity may explain some of the physiological changes occurring in panic attacks and be contributing to the origin of panic.

Mental disorders among alcoholics. Relationship to age of onset and cerebrospinal fluid neuropeptides.

Eighty-one percent of 339 alcoholics participating in a research program were found to have associated mental disorders. Alcoholics with onset of heavy drinking before 20 years of age had significantly more antisocial personality traits, drug abuse, bipolar disorder, panic disorder, suicide attempts, and paternal alcoholism than alcoholics with onset after age 20 years. Alcoholics with onset before and after 20 years of age also differed significantly from each other for cerebrospinal fluid concentrations of diazepam-binding inhibitor and somatostatin. These results support the notion that age of onset may delineate subgroups of alcoholics with significant clinical and neurochemical differences.

Pathological gambling. A psychobiological study.

We investigated psychobiological substrates of pathological gambling by measuring levels of norepinephrine, monoamine metabolites, and peptides in cerebrospinal fluid, plasma, and urine. Pathological gamblers had a significantly higher centrally produced fraction of cerebrospinal fluid levels of 3-methoxy-4-hydroxyphenylglycol as well as significantly greater urinary outputs of norepinephrine than controls. These results suggest that pathological gamblers may have a functional disturbance of the noradrenergic system. This system has been postulated to underlie sensation-seeking behaviors, aspects of which are thought to be abnormal among pathological gamblers.

Hypothalamic-pituitary-adrenal axis functioning and cerebrospinal fluid corticotropin releasing hormone and corticotropin levels in alcoholics after recent and long-term abstinence.

We assessed the plasma corticotropin (adrenocorticotropic hormone) and cortisol responses to ovine corticotropin releasing hormone (oCRH) and the cerebrospinal fluid levels of CRH and corticotropin in alcoholics at various durations of abstinence and compared these variables with age-equivalent controls. Alcoholics who were tested at 1 week of abstinence (n = 11) demonstrated a significantly attenuated corticotropin response to oCRH compared with their response at 3 weeks of abstinence. Nine of these alcoholic patients demonstrated a significantly blunted corticotropin response at both 1 and 3 weeks of abstinence compared with controls (n = 15). A markedly exaggerated corticotropin response to oCRH, associated with tachycardia, was exhibited by 2 alcoholics at both 1 and 3 weeks of abstinence. Alcoholics who were abstinent greater than 3 weeks did not differ in their response to oCRH compared with controls. Controls demonstrated a significant inverse correlation between baseline cortisol levels and the cortisol response to oCRH. This correlation was not evident in any of the alcoholic groups, including those patients who were abstinent greater than 6 months. There was a positive correlation between cerebrospinal fluid concentrations of CRH and corticotropin in all patient groups. These findings indicated that alcoholics have significantly altered hypothalamic-pituitary-adrenal axis functioning up to 3 weeks following the cessation of drinking, with a more subtle impairment present for greater than 6 months following abstinence.

Effective pharmacotherapy of alcoholic amnestic disorder with fluvoxamine. Preliminary findings.

Ten patients with alcoholic chronic organic brain disease were categorized as having alcohol amnestic disorder, or Korsakoff's psychosis (n = 6), dementia associated with alcoholism (n = 3), or compensated alcoholic liver disease (n = 1). All patients had severe deficits in memory for recently acquired information (episodic memory). Patients with alcohol dementia also showed global intellectual decline, including decreased performance on measures of semantic (knowledge) memory and reduction in levels of cerebrospinal fluid somatostatin. In a 4-week double-blind crossover design, the serotonin-uptake blocker fluvoxamine maleate (100 to 200 mg/d) was found to improve episodic memory in only the patients with alcohol amnestic disorder. These improvements in memory were significantly correlated with reductions in levels of cerebrospinal fluid 5-hydroxyindoleacetic acid, suggesting that facilitation of serotonergic neurotransmission may ameliorate the episodic memory failure in patients with alcohol amnestic disorder.

Temporal integration deficit in visual information processing by chronic schizophrenics.

The primary objective of the present study was to evaluate speed of visual information processing of chronic schizophrenics and normal subjects. Retarded information processing by schizophrenics has been attributed to a dysfunction at the earliest stage of processing. In the present study, by using a backward-masking paradigm and varying target duration we were able to evaluate whether schizophrenic and normals conform to an iconic or visual persistence theory of processing. Also, we evaluated whether schizophrenic and normal information processing is a function of the total time a stimulus is available for viewing prior to disruption (stimulus onset asynchrony, SOA), or whether it is the time following the stimulus offset prior to disruption by the mask (interstimulus interval, ISI). The former conforms more closely to a visual persistence and the latter to an iconic notion of processing. The results indicate that schizophrenics and normals conform to the processing of information as a function of the SOA as opposed to ISI. However, schizophrenic processing during the period of temporal integration (i.e., up to 130 msec) was significantly retarded when compared to normal controls. These findings suggest that for chronic schizophrenics, visual signals associated with target processing during the temporal integration period have either decayed at a slower rate or are more unstable than those of normals. Also discussed is the compatability of these findings with a visual persistence as opposed to an iconic model of information processing.

The benzodiazepine antagonist Ro 15-1788 does not antagonize the ethanol withdrawal syndrome.

It has been suggested that the signs and symptoms of the ethanol withdrawal syndrome may be due to the increased production of an "inverse agonist" that binds to the central benzodiazepine (BZ) recognition site in the brain. Ro 15-1788 (a potent antagonist at the central BZ recognition site), diazepam, and Ro 15-1788 plus diazepam were administered to groups of rats undergoing overt ethanol withdrawal. Ro 15-1788 did not alter the severity of the ethanol withdrawal reactions, but antagonized the ameliorative effect of diazepam. The results of our studies suggest that (1) the ethanol withdrawal syndrome is not produced by an endogenous ligand acting on the central BZ recognition site, and (2) diazepam decreases the severity of the ethanol withdrawal syndrome, at least in part, by its action at the central BZ recognition site.

Cerebrospinal fluid thyrotropin-releasing hormone concentrations in alcoholics and normal controls.

Alterations in hypothalamic-pituitary-thyroid axis function have been reported in alcoholism. Blunting of the thyroid-stimulating hormone (TSH) response to thyrotropin-releasing hormone (TRH) occurs in approximately 25% of alcoholic patients. Using a sensitive radioimmunoassay that allows TRH itself to be measured in cerebrospinal fluid (CSF), CSF concentrations of TRH were measured in alcoholics and normal controls. There was no significant difference in TRH concentrations between the groups. However, among the controls there was a significant correlation between CSF concentrations of the major serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) and CSF concentrations of TRH. This correlation was lacking in the alcoholics. These findings are of interest because basic neurobiological studies have reported that TRH and serotonin are co-localized in certain neurons in the rat central nervous system.

Inverse relationship between CSF TRH concentrations and the TSH response to TRH in abstinent alcohol-dependent patients.

The authors performed the thyrotropin-releasing hormone (TRH) stimulation test and measured CSF concentrations of TRH in 13 abstinent alcohol-dependent subjects. They found an inverse correlation between the thyrotropin (TSH) response to TRH and endogenous CSF TRH concentrations. This finding supports the hypothesis that as the concentration of CSF TRH increases, anterior pituitary TRH receptor density decreases, resulting in a blunted TSH response to TRH stimulation.

Cocaine abuse among schizophrenic patients.

Initial studies have indicated that stimulant abuse is prevalent among schizophrenic persons. To assess the phenomenon of cocaine abuse by patients with schizophrenia, 17 male cocaine-abusing schizophrenic patients were compared with 22 male schizophrenic patients who did not use cocaine. The cocaine-abusing subjects had been hospitalized more frequently, were more likely to be of the paranoid subtype, and were more likely to be depressed at the time of interview. It appears that cocaine abuse may influence both the psychopathologic presentation of schizophrenic patients and the intensity of care that they require.

Limbic responsiveness to procaine in cocaine-addicted subjects.

OBJECTIVE: The limbic system plays a critical role in motivation, emotional expression, and memory. The authors investigated whether a state of permanent limbic neuronal hyperexcitability, or sensitization, is present in cocaine addicts as a consequence of repeated cocaine use. METHOD: Single photon emission computed tomography (SPECT) of regional cerebral blood flow (rCBF) was used to compare the central nervous system response to the limbic stimulus procaine in 10 cocaine-dependent male patients and 10 healthy comparison male subjects. RESULTS: The cocaine-addicted subjects demonstrated bilateral activation of the orbitofrontal cortex after the procaine challenge, whereas the comparison subjects showed activation of the anterior cingulate, bilateral insular, and right amygdalar regions. After receiving placebo, the cocaine-addicted subjects showed markedly lower rCBF in the bilateral orbitofrontal cortex than the comparison subjects. CONCLUSIONS: The pattern of hypoperfusion in the placebo state followed by heightened activation with procaine in the cocaine-addicted subjects is similar to the pattern of interictal hypoperfusion and ictal hyperperfusion that has been observed in subjects with epilepsy. The findings for the cocaine-addicted subjects may thus represent evidence of localized (orbitofrontal) sensitization.

CSF gamma-aminobutyric acid in alcoholics and control subjects.

Alcohol has widespread effects on the gamma-aminobutyric acid (GABA) system in the brain. This system in the brain is also postulated to have a role in anxiety, and alcoholics have been reported to have more anxiety disorders. Therefore, the authors undertook a study to compare CSF levels of GABA in abstinent alcoholic patients and normal control subjects. There was no significant difference between groups in CSF levels of GABA. Also, there was no significant difference in GABA level between alcoholic patients with histories of withdrawal seizures and those without such a history.

Disturbances of hypothalamic-pituitary-adrenal axis functioning during ethanol withdrawal in six men.

OBJECTIVE: Excessive exposure to glucocorticoids can have neurotoxic effects. The behavioral, cognitive, and neurochemical changes observed following the cessation of heavy drinking, therefore, may be associated with disturbances of the hypothalamic-pituitary-adrenal (HPA) axis. To investigate HPA axis disturbances during the ethanol withdrawal syndrome, the authors examined diurnal changes in plasma cortisol in six alcohol-dependent men following the abrupt discontinuation of alcohol intake. METHOD: Plasma cortisol concentrations were quantified every 30 minutes for 24 hours in the early stage (1 day after cessation) and the middle to late stage (3 days after cessation) of the ethanol withdrawal syndrome as well as after the resolution of acute symptoms (8 days or more after cessation). RESULTS: Plasma cortisol concentrations were almost twice as high during acute withdrawal as they were following recovery. The duration of the cortisol diurnal cycle on the first day of withdrawal was negatively correlated with the severity of withdrawal. CONCLUSIONS: There is a marked activation of the HPA axis associated with the ethanol withdrawal syndrome. The authors hypothesize that this activation may account for some of the signs and symptoms of acute and subacute withdrawal. They discuss the potential long-term physiological effects of the episodic increases in cortisol associated with repeated episodes of ethanol withdrawal. The alterations in cortisol rhythmicity during early withdrawal may also have clinical implications.

Cerebrospinal fluid concentrations of corticotropin-releasing hormone (CRH) and diazepam-binding inhibitor (DBI) during alcohol withdrawal and abstinence.

The neuropeptides diazepam binding inhibitor (DBI) and corticotropin-releasing hormone (CRH) elicit anxietylike symptoms when administered intracerebroventricularly to laboratory animals. Because of the similarities between the symptoms of certain anxiety states and the alcohol withdrawal syndrome, we hypothesized that increased secretion of either of these endogenous neuropeptides may, at least in part, be responsible for the symptoms of alcohol withdrawal. We therefore measured DBI and CRH concentrations in cerebrospinal fluid (CSF) of 15 alcohol-dependent patients during acute withdrawal (Day 1) and again at 3 week's abstinence (Day 21). In addition, plasma concentrations of cortisol were measured to evaluate the relationship between pituitary-adrenal axis activation and CSF CRH concentrations. CSF CRH (p < .04), but not CSF DBI, was significantly higher on Day 1 than on Day 21. Although there was a significant decrease in plasma cortisol from Day 1 to Day 21 (p < .001), a significant correlation between CSF CRH and plasma cortisol concentrations was not observed at either time point. Neither CSF neuropeptide correlated with clinical measures of withdrawal severity. These tentative findings may implicate CRH, but not DBI, in the pathogenesis of alcohol withdrawal. Alternately, the central release of CRH and DBI may not be adequately reflected in lumbar CSF.

Developmental, behavioral, and opiate receptor changes after prenatal or postnatal beta-endorphin, CRF, or Tyr-MIF-1.

Developmental and long-term behavioral effects of perinatal injection of beta-endorphin (BE), CRF and Tyr-Pro-Leu-Gly-NH2 (Tyr-MIF-1) in male rats were investigated along with the possibility that opiate receptors may be altered by the injection of BE during this critical time. Daily injections of peptide were given to pregnant females (100 micrograms/rat) in the week before birth or to the offspring (50 micrograms/rat) of untreated mothers during the first week of life. Prenatal BE and CRF reduced body weight on day 1, in contrast to Tyr-MIF-1 which produced a significant increase over controls by day 7 as well as a slight but significant acceleration of eye opening. Among the postnatal treatments, CRF-treated animals showed the most dramatic changes. These included decreased body weight, accelerated eye opening, and, in adulthood, increased open field rearing behavior and a tendency for a monotonic body temperature response to low doses of morphine, in contrast to the biphasic response shown by controls. BE, when given to pregnant mothers, increased the number (Bmax) of [3H]naloxone-labeled (mu) receptors in whole brains of offspring assayed on day 14, but it did not significantly alter [3H]D-Ala-D-Leu-enkephalin-labeled (delta) receptors. In contrast, a significant decrease in both mu and delta receptors was observed on day 14 in rats given BE postnatally. These differences in receptors were no longer apparent in adulthood, and no significant differences in tail-flick response were detectable at this time. Nevertheless, some of the effects of these three peptides endured well beyond their presence, and for BE included changes in the number of opiate receptors.

Cocaine discrimination: relationship to local anesthetics and monoamine uptake inhibitors in C57BL/6 mice.

Although the discriminative properties of cocaine have been examined extensively in rats, and to a lesser extent in other species, there are currently no reports on cocaine discrimination by mice. In one of our experiments, C57BL/6 (C57) mice acquired cocaine discrimination (10 mg/kg training dose) and exhibited dose responsive generalization to lower doses of the drug, which was similar to previous reports using rats. In addition, mazindol, a general monoamine uptake inhibitor similar to cocaine, and nomifensine, which is relatively specific for the dopamine transporter, substituted completely for cocaine, as described for rats. In contrast, there was little substitution evidenced by monoamine uptake inhibitors relatively specific for the norepinephrine transporter (nisoxetine) or for the serotonin transporter (fluoxetine), or by the local anesthetics procaine or lidocaine. In our second experiment, neither cocaine nor mazindol substituted for procaine in animals trained to discriminate the local anesthetic (100 mg/kg) although lidocaine substituted completely for the procaine cue. These experiments emphasize the importance of the dopamine transporter in mediating the discriminative stimulus effects of cocaine in C57 mice. The lack of cross generalization between cocaine and procaine suggests that the anesthetic properties of cocaine contribute little toward its discrimination by this mouse strain.

Alcohol intoxication reduces visual sustained attention.

Effects of alcohol intoxication on visual sustained attention were studied using a vigilance task entailing detection of degraded target stimuli. Data were obtained in separate sessions under four ethanol doses, ranging from 0 (placebo) to 1.05 g/kg lean body weight, with periodic maintenance dosing of 0.12 g/kg. Intoxication lowered the overall level of detection performance, and in addition produced dose-related increases in the rate of performance decrement over time. Analysis of performance data using techniques derived from Signal Detection Theory indicated that the decrements were due specifically to alterations in perceptual sensitivity. Examination of eye movements and blinks indicated that the effects of ethanol were not mediated peripherally. Rather, alcohol appears to have deleterious effects on central processing capacity and the availability of capacity over time. The alcohol-related failure of sustained attention may contribute to increased accident risk in tasks requiring continuous performance.