Implications of recent neuropsychopharmacologic research for understanding the etiology and development of alcoholism

Recent studies in animals and humans have begun to provide insight into the neuropsychopharmacologic basis of alcohol consumption and dependence. Studies involving the serotonergic and opioidergic neurotransmitter systems have shown the most consistent results. Concurrent nosologic developments have led to the identification of subtypes of alcoholism on the basis of their clinical features and patterns of inheritance of alcoholism. These subtypes, which have implications for both the etiology and development of alcoholism, have also been linked theoretically to specific neurotransmitter systems. Consequently, the typologies both provide a hypothetical basis for selecting specific pharmacotherapies and have implications for molecular genetic investigation. This article selectively reviews the literature in these various areas in an effort to enhance understanding of the etiology and development of alcoholism.

Issues in the definition and measurement of drinking outcomes in alcoholism treatment research

This article reviews methodological and conceptual issues regarding the choice of drinking outcome measures in alcoholism treatment research. The following issues are discussed: Should drinking outcomes be conceptualized in terms of an underlying unitary disorder, or should provision be made for independent outcomes that cover a wide variety of dimensions? Which drinking outcomes are typically measured in treatment evaluation studies and how are they operationalized? What are the empirical associations among drinking outcome measures? If multiple outcomes are measured, which should be given primary importance? Over what period of time should treatment outcome be evaluated? What procedures can be used to detect, correct or prevent the response bias associated with verbal report methods? Because outcome measures need to fit the hypotheses and practical needs of a particular study, it is unlikely that complete standardization can be achieved across all studies. Nevertheless, given the importance of drinking outcomes and the need for economy, two primary dependent measures are recommended: (1) proportion of available drinking days abstinent; and (2) intensity of drinking, as defined by the total amount consumed (in ounces absolute alcohol) during the follow-up period divided by the number of actual drinking days. This article also proposes a strategy that may help to guide the selection of outcome measures in future research.

Mood congruent and incongruent psychotic depressions: are they the same?

DSM-III and DSM-III-R instruct the clinician, if possible, to classify major depression with psychotic features into either the mood congruent (MC) or mood incongruent (MI) subtype. Patients hospitalized on a psychiatric unit for major depression with psychotic features were classified as predominantly MC or MI. The MC and MI groups did not differ significantly on a number of demographic or symptom severity variables. Thirteen (50%) MI patients experienced at least one MC symptom and 10 (71%) MC patients experienced at least one MI symptom. Overall, 25 (58%) of these patients experienced both MC and MI symptoms. This study demonstrates that subtyping psychotic depression into MC and MI subtypes is seldom an 'either-or' decision. Indeed, these results combined with findings from previous research suggests that there is no compelling scientific evidence for subclassifying psychotic depression into subtypes.

Carbohydrate-deficient transferrin as a measure of immoderate drinking: remaining issues

A growing body of investigations demonstrate that elevated levels of carbohydrate-deficient transferrin (CDT) effectively distinguishes alcoholics recently consuming large amounts of alcohol from light social drinkers or teetotalers. Nevertheless, important questions still remain concerning the value of CDT as a more generalized marker of alcohol consumption. Most important, the nature of the drinking pattern, including quantity and frequency, necessary to raise levels of CDT significantly remains unclear. Neither has research convincingly demonstrated that CDT is as accurate a marker for women, young adults, or non-Caucasian ethnic groups as for White, middle-aged men. Whereas CDT might serve as a useful outcome measure in trials of alcoholism treatment effectiveness, current research suggests that CDT is of limited value in identifying problematic drinking in general medical or community settings in which a broad continuum of drinkers is represented. Combining CDT with other biochemical or self-report screening measures may, however, improve sensitivity in these contexts. At present, the most accurate laboratory technique to detect CDT seems to be isoelectric focusing. Additional research, however, is needed to resolve the issue of whether CDT is best quantitated as a simple value or if its ratio to total transferrin or non-CDT results in higher predictive validity.

A correlational study of carbohydrate-deficient transferrin values and alcohol consumption among Hispanic college students

One hundred and forty-eight U.S. college students from a small southwestern university were asked to provide or complete the following: the Michigan Alcoholism Screening Test (MAST), a structured alcohol-use interview, and a 10-ml blood sample to be assayed for carbohydrate-deficient transferrin (CDT) levels and gamma-glutamyl-transpeptidase (GGTP) activity. Using the data obtained in the interview, only 2 females and 5 males were identified as heavy drinkers. Conclusions regarding the efficacy of the biochemical markers are therefore limited. It was found that CDT levels were significantly and positively correlated with various measures of alcohol consumption among males. There was no similar association between CDT, or GGTP, and alcohol consumption within the female sample.

Carbohydrate-deficient transferrin and gamma-glutamyltransferase as markers of heavy alcohol consumption: gender differences

Carbohydrate-deficient transferrin (CDT) has been described as a more specific and sensitive marker of recent heavy alcohol consumption as compared with the current tests now available, such as gamma-glutamyltransferase (GGT). Most of the data generated from European populations have not compared the utility of CDT and GGT in the detection of heavy alcohol consumption as a function of gender. We examined the ability of both CDT and GGT to discriminate between 42 men and 18 women with heavy alcohol consumption (> 60 g/day) admitted to an alcohol detoxification center and a group of controls matched for age, race, and gender. CDT was higher, but GGT lower, in control females compared with males. Both CDT and GGT were higher in patients of both genders. At specificities > 90%, the sensitivity of CDT for detecting male alcohol abusers was 79% and for female alcohol abusers 44%. For GGT, the sensitivities were 65% and 44%, respectively. When both tests were used simultaneously, the sensitivity for the detection of alcohol abusers increased to 95% for males and 72% for females. Receiver Operator Characteristic analysis tended to confirm the superiority of CDT over GGT in the detection of heavy alcohol consumption in males, but not in females. A positive relationship was found between serum iron levels and CDT in control females but in no other group. The concordant findings of this American study with those in similar French and Finnish clinical populations, utilizing similar assay techniques, suggest that the measurement of CDT is clinically more useful than GGT in detecting recent heavy alcohol consumption in males.(ABSTRACT TRUNCATED AT 250 WORDS)

Medications for Treating Alcoholism

Researchers are evaluating medications to assist in treating alcoholism. Such medications may be used to treat withdrawal or co-occurring psychiatric disorders or as an adjunct to psychosocial treatment.

Response of psychotic depression subtypes to pharmacotherapy

Patients with psychotic depression respond well when treated with a combination of an antidepressant and antipsychotic medication. We previously reported that they will respond in a similar fashion when treated with amoxapine monotherapy. There are few prospective studies on the pharmacologic treatment response of psychotic depression subtypes. We treated 37 inpatients, 21 with mood congruent (MC) psychotic depression and 16 with mood incongruent (MI) psychotic depression, in a randomized double-blind fashion with either the combination of amitriptyline and perphenazine or with amoxapine for 4 weeks. Depression and psychosis ratings improved in a similar manner in both the MC or MI patients irrespective of medication treatment group. Global response rates were similar in the MI patients and MC patients. The data suggest that classifying psychotic depression into MC versus MI subtypes may have limited acute prognostic value in pharmacotherapy response rates.

A placebo-controlled trial of buspirone in anxious inpatient alcoholics

The present study is a double-blind control trial of buspirone versus placebo in highly anxious alcoholics who recently completed inpatient detoxification for alcoholism. Subjects met DSM-III-R criteria for generalized anxiety syndrome and/or other nonpanic forms of anxiety disorders and alcohol dependence. Male veterans aged 21 to 65 were randomized to 45 to 60 mg/day of buspirone (n = 33) or placebo (n = 34). Anxiety scores, as measured by the Hamilton Anxiety Scale and other anxiety measures, declined significantly for both groups, but there were no differential group differences throughout the 6-month treatment period. Survival analysis measuring time to study drop out, time to first drink, time to 5 consecutive drinking days, and time to first intoxication indicated no significant differences between groups. The number of standard drinks per drinking day for nonabstainers also did not differ between groups. In the present study anxious alcoholics taking buspirone did not receive any benefit over placebo on a number of anxiety and alcohol use measures.

Aspirin dose-dependently reduces alcohol-induced birth defects and prostaglandin E levels in mice

The purpose of the present study was threefold. The first purpose was to determine if aspirin (ASA) decreases alcohol-induced birth defects in mice in a dose-dependent fashion. The second purpose was to see if the antagonism of alcohol-induced birth defects afforded by ASA pretreatment was related to dose-dependent decreases in prostaglandin E (PGE) levels in uterine/embryo tissue. The third purpose was to determine if ASA pretreatment altered maternal blood alcohol level. In experiments 1 and 2, pregnant C57BL/6J mice were administered ASA (0, 18.75, 37.5, 75, 150, or 300 mg/kg) on gestation day 10. One hour following the subcutaneous injection of ASA, mice received alcohol (5.8 g/kg) or an isocaloric sucrose solution intragastrically. In experiment 1 the incidence of birth defects was assessed in fetuses delivered by caesarean section on gestation day 19. In experiment 2 uterine/embryo tissue samples were collected on gestation day 10 1 hr following alcohol intubation for subsequent PGE analysis. In experiment 3 blood samples were taken at five time points following alcohol intubation from separate groups of alcohol-treated pregnant mice pretreated with 150 mg/kg ASA or vehicle. The results from the three experiments indicated that 1) ASA dose-dependently reduced the frequency of alcohol-induced birth defects in fetuses examined at gestation day 19, (2) ASA decreased the levels of PGE in gestation day 10 uterine/embryo tissue in a similar dose-dependent fashion, and 3) ASA pretreatment did not significantly influence maternal blood alcohol levels. These results provide additional support for the hypothesis that PGs may play an important role in mediating the teratogenic actions of alcohol.

Effect of ibuprofen on alcohol-induced teratogenesis in mice

The purpose of the present study was to examine the effect of the prostaglandin synthetase inhibitor ibuprofen (IBU) on the teratogenic actions of alcohol. On day 10 of pregnancy, C57BL/6J mice were injected subcutaneously with 25 mg/kg IBU or vehicle control. One hour later, the mice were intubated with 5.8 g/kg alcohol or an isocaloric control solution. A group injected subcutaneously with 150 mg/kg aspirin, followed by 5.8 g/kg alcohol 1 hr later, served as a positive control. The results showed that maternal alcohol treatment resulted in significantly decreased fetal weight and an increased number of fetuses with limb and kidney defects. Implantation sites and prenatal mortality were not affected. IBU did not have any effect on these dependent variables. IBU statistically antagonized the teratogenic effects of alcohol on fetal weight and dysmorphology. These effects, however, were not as marked as in the Aspirin-Alcohol positive control group. These results are discussed in the context of clarifying the role of prostaglandins in the etiology of alcohol-induced birth defects.

Increased severity of alcohol withdrawal in in-patient alcoholics with a co-existing anxiety diagnosis

The purpose of this study was to determine whether alcoholics with a co-existing anxiety disorder (dual-diagnosed group) experienced different withdrawal symptomatology from alcoholics without an anxiety disorder (alcohol-only group). Symptoms of alcohol withdrawal were measured on admission to an in-patient treatment program and throughout treatment (days 0, 2, 7, 14 and 21) using the revised Clinical Institute Withdrawal Assessment for Alcohol (CIWA-Ar) scale. The dual-diagnosed group exhibited more severe alcohol withdrawal, as indicated by higher total CIWA-Ar scores, at all time points than the alcohol-only group. The possibility that anxiety disorders and alcohol withdrawal share a common neurochemical basis and that the CIWA-Ar scale may be useful as a screening instrument for anxiety disorders in alcoholics is discussed.

Perspectives on the pathophysiology of fetal alcohol syndrome

Fetal alcohol syndrome (FAS) is a major known cause of fetal malformations and mental retardation. Prevention/intervention of FAS can only be achieved with identification of the mechanisms by which alcohol induces birth defects. The purpose of this paper is to discuss the data on possible mechanisms of FAS, and to give a number of suggestions for future research areas.

Valproate potentiates and picrotoxin antagonizes the anxiolytic action of ethanol in a nonshock conflict task

The purpose of this study was to examine the effects of the indirect GABA agonist valproate and the indirect GABA antagonist picrotoxin on the anxiolytic (anti-conflict) activity of ethanol in a behavioral conflict task that does not employ electroshock. This task (negative contrast) quantifies how animals respond to an abrupt, unexpected reduction in reward. Treatment with valproate alone did not elevated depressed behavior engendered by abrupt reduction in reward. However, when administered together with a sub-effective dose of ethanol (0.5 g/kg), valproate (50-200 mg/kg) dose-dependently potentiated the anxiolytic action of ethanol. Picrotoxin (2 mg/kg) antagonized the anxiolytic effects of a larger dose of ethanol (1.0 g/kg) given alone, as well as the ability of valproate to enhance the anxiolytic effects of smaller dose of ethanol (0.5 g/kg). As such, these data support a role for GABA in mediating the anxiolytic activity of ethanol.

Amoxapine versus amitriptyline combined with perphenazine in the treatment of psychotic depression

In a double-blind study lasting for 4 weeks, the authors compared the effectiveness of amoxapine, an antidepressant with potential antipsychotic properties, with a combination of amitriptyline plus perphenazine in the treatment of 38 patients who had the diagnosis of major depression with psychotic features (psychotic or delusional depression). Patients in each group showed similar improvement in depression and psychosis. There was a tendency for the patients treated with amitriptyline plus perphenazine to have higher global response rates. However, the patients given amoxapine had significantly fewer extrapyramidal side effects.

Thyrotropin and prolactin response to thyrotropin-releasing hormone in depressed and nondepressed alcoholic men

Thyrotropin-releasing hormone (TRH) stimulation tests were performed on 81 alcoholic men after at least 3 weeks of abstinence. Subjects were given 500 micrograms of TRH intravenously, and thyroid-stimulating hormone (TSH) and prolactin (PRL) were measured at baseline, and then 15 and 30 min later. Comparisons were made among alcoholics with (n = 27) and without (n = 54) a lifetime history of depression as determined by the Diagnostic Interview Schedule. Nine nondepressed, nonalcoholic subjects served as controls. Alcoholics with or without a depression history did not differ from each other or from control in TSH or PRL response area under the curve. Blunted TSH responses were present in 10 (12%) of the alcoholics and none of the controls when blunting was defined as a delta max TSH less than 5 microU/ml. When blunting was defined as a delta max TSH less than 7 microU/ml, 18 (22%) of the alcoholics and 1 (1%) of the controls were blunted. Conversely, 2 (2.5%) of the alcoholics had a delta max TSH greater than 32 microU/ml. All subjects were clinically euthyroid. Contrary to expectation, depressed subjects were slightly less likely to show blunted responses than nondepressed subjects. No relationship was found between neuroendocrine measurements and several measurements of alcoholism or depression. Some alcoholic subjects show a blunted TSH response to TRH injection, which may be a function primarily of the alcoholism itself. The precise mechanism remains unknown.

Ethanol increases PGE and thromboxane production in mouse pregnant uterine tissue

The teratogenic effect of ethanol in the C57BL/6J mouse can be attenuated by pretreatment with aspirin (ASA). One prominent effect of ASA is to inhibit prostaglandin (PGE) and thromboxane (TXB2) production. We examined the effect of in vivo ethanol exposure on PGE and TXB2 production in a uterine-embryo tissue sample of C57BL/6J mice either before or after in vivo ASA pretreatment on day 10 of gestation. Ethanol increased both PGE and TXB2 production by approximately 20%. ASA caused a marked reduction of PGE and TXB2 in both control and ethanol groups by approximately 80-90%. The mouse strain, gestation time, and study parameters used in this study were the same as in the previously reported ASA attenuation of the teratogenic effect of ethanol. Therefore, the present data add additional support to the hypothesis that prostaglandin and/or thromboxane production may be involved in at least some aspects of fetal alcohol syndrome.

CSF prostaglandin-E in agoraphobia with panic attacks

Prostaglandins are thought to act as neuromodulators of both central catecholamine and endocrine systems. Abnormalities of these systems have been described in affective disorders, in general, and in agoraphobia with panic attacks, in particular. This study measured basal prostaglandin-E (PGE) cerebrospinal fluid (CSF) levels in 20 patients with agoraphobia with panic attacks and 10 nonpsychiatric controls. In a subgroup of patients and controls, CSF levels of adrenocorticotrophic hormone (ACTH) and corticotropin-releasing factor (CRF) were also measured. There was no significant difference in CSF PGE levels between patients and controls. However, patients with higher depression scores had lower CSF PGE levels. CSF PGE levels tended to correlate with CSF ACTH, but not CSF CRF in the patient group, in general, and in the female patients, in particular. These findings do not support an abnormality in basal CNS PGE production in agoraphobia with panic attacks, but suggest further study of the PGE modulatory effect on the hypothalamic-pituitary-adrenal axis in this disorder.

The thyroid axis and desipramine treatment in depression

Although there has been much recent investigation of the role of thyroid function in affective illness, few studies have addressed the effects of the tricyclic antidepressants on the pituitary-thyroid axis. In the present study, thyroid functions (TFTs) and thyrotropin-releasing hormone (TRH) stimulation of thyroid-stimulating hormone (TSH) were measured before and after treatment with desipramine (DMI) in 13 men with a diagnosis of major depressive disorder. All subjects had normal TFTs and baseline TSH measured in a drug-free state at the initiation of the study. Both mean free thyroxine index and baseline TSH decreased after DMI treatment. The amount of decrease in baseline TSH correlated with increase in delta TSH. Four subjects had blunted delta TSH (delta TSH less than or equal to 5 microIU/ml); three of these subjects "normalized" with treatment (delta TSH less than or equal to 5 microIU/ml; greater than or equal to 20 microIU/ml). Two subjects had a high delta TSH, and both "normalized" during treatment. The decrease in both free T4 index and TSH suggests a down-regulation of the thyroid axis at the hypothalamic level. "Normalization" of subtle dysregulation of the thyroid axis is suggested as a mechanism of antidepressant therapy in the treatment of some depressions.

The benzodiazepine receptor inverse agonist RO15-4513 exacerbates, but does not precipitate, ethanol withdrawal in mice

RO15-4513, an imidazobenzodiazepine that has been reported to antagonize several behavioral and biochemical actions of ethanol, was given to C3H mice at various times during withdrawal from chronic (72 hours) continuous exposure to ethanol vapor. When administered immediately following chronic ethanol exposure, RO15-4513 (6 or 12 mg/kg) did not influence the withdrawal response. However, when given at subsequent times (3, 5, and 8 hours postethanol withdrawal), RO15-4513 significantly increased the severity of the withdrawal response in ethanol-exposed mice. Moreover, this exacerbation was completely reversed by pretreatment with the benzodiazepine receptor antagonist RO15-1788. Thus, these data indicate that the benzodiazepine inverse agonist, RO15-4513, is capable of exacerbating, but not precipitating, ethanol withdrawal.

PGE measurement in mouse embryos and uterine/embryo tissue

Embryonic tissue of rodents and other species has been reported to produce prostaglandins (PG) of the E series during gestation. We attempted to establish the presence of PGE in C57BL/6J mouse embryos and peri-embryonic tissue as an initial step in examining the role of maternal ethanol treatment on PG production. Gestation day 10 embryos were found not to produce or degrade PGE. However, a tissue complex which included embryonic tissue, peri-embryonic membranes, placenta and uterus was capable of producing PGE from both endogenous and exogenous arachidonic acid. Furthermore, in vivo and in vitro aspirin was able to suppress PGE production from this tissue. It is concluded that gestation day 10 C57BL/6J mouse embryonic tissue, unlike that of rat, is not capable of measurable PGE production. However, uterine and peri-embryonic tissues, needed to support pregnancy, are capable of significant PGE production.

Role of alcohol-induced hypothermia in mediating the teratogenic effects of alcohol in C57BL/6J mice

The purpose of this study was to determine the role of alcohol-induced maternal hypothermia in the teratogenic actions of alcohol. C57BL/6J mice were administered an acute dose of alcohol (5.8 g/kg orally) or isocaloric sucrose on day 10 of gestation. One half of each group was placed for 6 hr in an incubator set at 32 degrees C and the other half was housed in the incubator at room temperature (22 degrees C). As expected, acute prenatal alcohol exposure at this time of gestation was associated with decreased birth weight and an increase in limb and kidney malformations. The significant alcohol x environmental temperature interaction on these dependent variables indicated that the teratogenic insult was not attenuated, but was in fact even greater for the 32 degrees C/alcohol group. An absence of a main effect of environmental temperature indicated that the 32 degrees C environment, per se, was not teratogenic. Thus, maternal hypothermia is probably not an etiological factor in animal models of fetal alcohol syndrome. Moreover, antagonism of alcohol-induced maternal hypothermia exacerbates the teratogenic actions of alcohol observed at room temperature.