Depressive symptoms modulate the subjective and physiological response to cocaine in humans

Influence of Clinical Markers of Dopaminergic Behaviors on Depressive Symptoms During Withdrawal in Cocaine Users

Background: During cocaine withdrawal, transient depressive symptoms that do not meet the criteria for depression, but promote relapse, are frequently observed. Their temporality could evoke a role of dopamine, especially since the underlying mechanism of these depressive symptoms is not well understood. We hypothesized that variation in the dopaminergic activity profile, modeled from clinical markers, could be implicated in the development of depressive symptoms during cocaine withdrawal. Methods: We compared patients reporting depressive symptoms (RDS+) or not (RDS-) during cocaine withdrawal. We evaluated dopaminergic activity through indirect clinical markers based on the known dopaminergic behaviors. A combined criterion was constructed for hyper and hypo dopaminergic models according to the O'Brien method and illustrated by the Hedges' effect-size and forest-plot graph. A multidimensional factorial analysis was carried out to determine which parameters discriminate RDS+/RDS- patients. Results: 313 patients were included, and 77% reported depressive symptoms during cocaine withdrawal. Hyperdopaminergic variables used to discriminate the two groups had a large overall effect size (-0.669) and included psychotic symptoms (-0.524), hallucinations (-0.548), and delusions (-0.528). The overall effect of the hypodopaminergic component was considerable (-0.604) with a large effect size for the severity of dependence (-0.616), withdrawal symptoms (-0.578), and anhedonia (-0.528). The combined model including hyperdopaminergic and hypodopaminergic components had the largest effect size (-0.785). Conclusion: The dopaminergic activities profile, assessed by indirect clinical markers, seems to characterize patients with depressive symptoms very well during cocaine withdrawal. RDS+ patients reported moreover higher levels of psychotic symptoms and more severe cocaine use disorder than RDS-.

Factors associated with the absence of cocaine craving in treatment-seeking individuals during inpatient cocaine detoxification

BACKGROUND

Anecdotal evidence suggests a substantial proportion of individuals with cocaine use disorder do not report craving during inpatient detoxification.

OBJECTIVE

To examine prevalence and clinical correlates of consistent absence of cocaine craving among inpatients during detoxification. We hypothesized that craving absence would be associated with less severity of cocaine use, depression, and anxiety. Alternative explanations were also explored.

METHODS

Craving absence (i.e., non-cravers) was defined as a daily score of zero across two separate craving visual analogue scales in each of the inpatient days. Participants scoring ≥1 on ≥1 day were considered cravers. Severity of cocaine use disorder as well as in-treatment depression and anxiety were assessed. Alternative contributors included presence of cocaine and other substances in urine at admission, in-treatment prescription of psychotropic medications, treatment motivation, executive function, interoception, and social desirability.

RESULTS

Eighty-seven participants (78.2% males) met criteria as either non-cravers (n = 29; 33.3%) or cravers (n = 58; 66.7%). Mean length of admission in non-cravers and cravers was, respectively, 10.83 and 13.16 days. Binary logistic regression model showed that non-cravers scored significantly lower than cravers on cocaine use during last month before treatment (OR, 95% CI; 0.902, 0.839-0.970), in-treatment depression (OR, 95% CI; 0.794, 0.659-0.956), and in-treatment prescribing of antipsychotics (OR, 95% CI; 0.109, 0.014-0.823). Model prediction accuracy was 88.9%.

CONCLUSIONS

One in three patients undergoing inpatient detoxification experienced absence of craving, linked to less pretreatment cocaine use, better mood, and decreased administration of antipsychotics. Findings may inform pretreatment strategies and improve treatment cost-effectiveness.

The neurosteroid dehydroepiandrosterone sulfate, but not androsterone, enhances the antidepressant effect of cocaine examined in the forced swim test--Possible role of serotonergic neurotransmission

One of the mechanisms of cocaine's actions in the central nervous system is its antidepressant action. This effect might be responsible for increased usage of the drug by individuals with mood disorders. Higher endogenous levels of the excitatory neurosteroid dehydroepiandrosterone sulfate (DHEAS) were reported to correlate with successful abstinence from cocaine use in addicts, but a clinical trial showed that supplementation with a high dose of DHEA increased cocaine usage instead. Such ambiguous effects of DHEA(S) could potentially be linked to its influence on the antidepressant effect of cocaine. In this study we tested DHEAS and its metabolite, androsterone, for interactions with cocaine in animal model of depression (forced swim test) and examined the effects of both steroids and cocaine on serotoninergic neurotransmission. All substances were also tested for influence on locomotor activity. A cocaine dose of 5mg/kg, which had no significant effect on locomotor activity, was chosen for the forced swim test. Neither DHEAS nor androsterone showed any antidepressant action in this test, while cocaine manifested a clear antidepressant effect. Androsterone slightly reduced the antidepressant influence of cocaine while DHEAS markedly, dose-dependently enhanced it. Such an effect might be caused by the influence of DHEAS on serotonin neurotransmission, as this steroid decreased serotonin concentration and turnover in the striatum. When DHEAS and cocaine were administered together, the levels of serotonin in the striatum and hippocampus remained unchanged. This phenomenon may explain the additive antidepressant action of DHEAS and cocaine and why co-administration of DHEAS and cocaine increases drug use.

A comparison of impulsivity, depressive symptoms, lifetime stress and sensation seeking in healthy controls versus participants with cocaine or methamphetamine use disorders

Previous research has focused on developing theories of addiction that may explain behavior in cocaine- and methamphetamine-dependent individuals. The primary goal of this report was to compare and contrast the prevalence of self-reported measures of impulsivity, depression, lifetime stress and sensation-seeking in healthy controls versus individuals with cocaine or methamphetamine use disorders. Twenty-nine individuals with cocaine use disorders and 31 individuals with methamphetamine use disorders were matched with 31 healthy control participants on several demographic variables. All participants were administered behavioral questionnaires including the Barrett Impulsiveness Scale (assessing impulsivity), Beck Depression Inventory II (assessing depression), Life Stressor Checklist-Revised (assessing lifetime stress) and the Impulsive Sensation Seeking Scale (assessing sensation-seeking). When compared to healthy controls, individuals with cocaine and methamphetamine use disorders had significantly higher levels of impulsivity and sensation-seeking. In addition, when compared to healthy controls, individuals with cocaine use disorders had significantly higher Beck Depression Inventory II scores, while individuals with methamphetamine use disorders had significantly higher Life Stressor Checklist-Revised scores. The results revealed that there were significantly higher levels of impulsivity, depression and sensation-seeking in cocaine users and significantly higher impulsivity, lifetime stress and sensation-seeking in methamphetamine users when compared to healthy controls.

Psychometric properties of the Spanish version of the Cocaine Selective Severity Assessment to evaluate cocaine withdrawal in treatment-seeking individuals

Reliable and valid assessment of cocaine withdrawal is relevant for treating cocaine-dependent patients. This study examined the psychometric properties of the Spanish version of the Cocaine Selective Severity Assessment (CSSA), an instrument that measures cocaine withdrawal. Participants were 170 cocaine-dependent inpatients receiving detoxification treatment. Principal component analysis revealed a 4-factor structure for CSSA that included the following components: 'Cocaine Craving and Psychological Distress', 'Lethargy', 'Carbohydrate Craving and Irritability', and 'Somatic Depressive Symptoms'. These 4 components accounted for 56.0% of total variance. Internal reliability for these components ranged from unacceptable to good (Chronbach's alpha: 0.87, 0.65, 0.55, and 0.22, respectively). All components except Somatic Depressive Symptoms presented concurrent validity with cocaine use. In summary, while some properties of the Spanish version of the CSSA are satisfactory, such as interpretability of factor structure and test-retest reliability, other properties, such as internal reliability and concurrent validity of some factors, are inadequate.

Pharmacological treatment of comorbid PTSD and substance use disorder: recent progress

Previous research has identified a strong association between posttraumatic stress disorder (PTSD) and substance use disorder (SUD), necessitating the development of treatments that address both conditions. Some pharmacotherapies are effective for the treatment of PTSD and SUD alone, however; no medications have been proven to be effective for the combination of these conditions. We review the recent advances in pharmacological treatment of comorbid PTSD and SUD. A randomized clinical trial of sertraline, a serotonin reuptake inhibitor (SSRI), did not show overall efficacy for comorbid PTSD and alcohol dependence (AD), although it may have efficacy among light drinkers. Another clinical trial demonstrated the efficacy of both disulfiram and naltrexone for the treatment of AD in individuals with PTSD. A more recent clinical trial suggested that norepinephrine uptake inhibitors may also have efficacy for the treatment of comorbid PTSD and AD. In animal and preliminary human studies, brain norepinephrine and glutamate/GABA have emerged as potential treatment targets for comorbid PTSD and SUD. Noradrenergic medications that are promising for comorbid PTSD and SUD include prazosin, guanfacine, and atomoxetine. Promising glutamate/GABA medications include topiramate, memantine, acamprosate, N-acetylcysteine (NAC), and ketamine. The safety and efficacy of these medications for the treatment of PTSD and SUD need to be tested in controlled clinical trials.

Cocaine use in the past year is associated with altitude of residence

OBJECTIVES

Recently, increased rates of suicide in US counties at higher altitudes have been noted. Because of the documented association between cocaine use and suicide, we hypothesized that there would be a correlation between incidence of cocaine use and altitude of residence.

METHODS

Cocaine use data were obtained from the Substate Substance Abuse Estimates from the 1999-2001 National Surveys on Drug Use and Health. Data related to the percentages of people 12 years or older who used cocaine in the past year. Average elevation for US counties was calculated using the Shuttle Radar Topography Mission elevation data set, and subject region elevation was calculated by averaging the weighted elevations of each region's relevant counties. The correlation between elevation of a substate region and incidence of cocaine use in that region was calculated using Pearson correlation coefficients.

RESULTS

A significant correlation exists between mean altitude of a substate region and incidence of cocaine use in that region (r = 0.34; P < 0.0001). Regression analysis controlling for age, sex, race, education level, income, unemployment, and population density was performed. Altitude remained a significant factor (P = 0.007), whereas male sex (P = 0.008) and possessing less than a college education (P < 0.0001) were also significant predictors of self-reported cocaine use in the past year. It is important to note that cocaine use was assessed in isolation of other drugs of abuse, an additional confounding variable.

CONCLUSIONS

This study demonstrates a significant correlation between altitude of substate region of residence and incidence of cocaine use. It is possible that stress response due to hypoxia is responsible; however, this requires further investigation. However, because other substance use was not assessed, specificity of this association is unknown. In addition, this correlation may help explain the increased rate of suicide in areas of higher elevation.

Pharmacotherapeutics directed at deficiencies associated with cocaine dependence: focus on dopamine, norepinephrine and glutamate

Much effort has been devoted to research focused on pharmacotherapies for cocaine dependence yet there are no FDA-approved medications for this brain disease. Preclinical models have been essential to defining the central and peripheral effects produced by cocaine. Recent evidence suggests that cocaine exerts its reinforcing effects by acting on multiple neurotransmitter systems within mesocorticolimibic circuitry. Imaging studies in cocaine-dependent individuals have identified deficiencies in dopaminergic signaling primarily localized to corticolimbic areas. In addition to dysregulated striatal dopamine, norepinephrine and glutamate are also altered in cocaine dependence. In this review, we present these brain abnormalities as therapeutic targets for the treatment of cocaine dependence. We then survey promising medications that exert their therapeutic effects by presumably ameliorating these brain deficiencies. Correcting neurochemical deficits in cocaine-dependent individuals improves memory and impulse control, and reduces drug craving that may decrease cocaine use. We hypothesize that using medications aimed at reversing known neurochemical imbalances is likely to be more productive than current approaches. This view is also consistent with treatment paradigms used in neuropsychiatry and general medicine.

Perfil dos usuários de crack que buscam atendimento em Centros de Atenção Psicossocial

O artigo descreve o perfil de 95 usuários de crack acolhidos em três Centros de Atenção Psicossocial (CAPS) da Região Metropolitana de Porto Alegre, no Sul do Brasil, entre agosto de 2009 e março de 2010. Todos os usuários de crack que buscaram atendimento no período foram entrevistados. Utilizou-se questionários desenvolvidos pela equipe, mais o Self-Reporting Questionnaire (SRQ-20) e inventários de critérios de dependência e abuso (SAMHSA). Houve predomínio de pacientes homens, adultos jovens, com escolaridade fundamental, sem ocupação regular, mas com renda individual informada, em uso frequente e pesado há mais de um ano, e a maioria preenchia critérios para dependência e abuso do crack e tinha escores elevados de SRQ-20. Os resultados evidenciam que os CAPS são buscados por usuários de crack em sofrimento, que deve ser valorizado, mas também a existência de algum tipo de seleção na oferta destes serviços, caracterizada pelas especificidades de renda, escolaridade e grupo primário de apoio aos entrevistados.

Effects of major depression on crack use and arrests among women in drug court

AIMS

We examined whether a current major depressive episode (MDE) at baseline predicted crack use and arrests at follow-up among women enrolled in drug court.

DESIGN

Primary analyses used zero-inflated Poisson (ZIP) and zero-inflated negative binomial (ZINB) regression analyses to predict both yes/no and number of (i) days of crack use and (ii) arrests at 4-month follow-up from current (30-day) MDE at baseline. Secondary analyses addressed risk conferred by current versus past MDE at baseline.

SETTING/PARTICIPANTS

Participants were 261 women in drug court.

MEASUREMENTS

MDE was assessed using the Diagnostic Interview Schedule. Days using crack and number of arrests were assessed using the Washington University Risk Behavior Assessment for Women.

FINDINGS

Having a current MDE at baseline predicted likelihood of crack use at follow-up, but not days of crack use among those who used. Current MDE at baseline did not predict presence or number of arrests at the 4-month follow-up. Women with current MDE at baseline were more likely to be using crack at follow-up than were those with recent (31+ days to 12 months) but not current MDE (odds ratio = 5.71); past MDE at baseline did not increase risk of crack use.

CONCLUSIONS

Predictors of any versus no crack use or arrests appear to differ from predictors of frequency of these behaviors. Current major depression, but not past major depression, appears to be associated with increased risk of crack use among women attending drug court.

Psychosocial treatments for cocaine dependence: the role of depressive symptoms

BACKGROUND

The association between cocaine use and depression has been frequently observed. However, less is known about the significance of depression in the treatment of cocaine use disorders. This study examined possible interrelations between drug use and depression severity among cocaine-dependent patients in psychosocial treatments for cocaine dependence.

METHODS

Monthly assessed drug use and depression severity scores of N = 487 patients during 6-month psychosocial treatments for cocaine dependence were analyzed using hybrid latent growth models.

RESULTS

Results indicated a moderate but statistically significant (z = 3.13, p < .01) influence of depression severity on increased drug use in the upcoming month, whereas drug use did not affect future depression severity.

CONCLUSIONS

Findings suggest that depression symptoms are an important predictor of drug use outcomes during psychosocial treatments for cocaine dependence and, hence, underline the importance of adequately addressing depression symptoms to improve treatment outcomes.

Gustatory and olfactory function in patients with unipolar and bipolar depression

Although the crucial distinction between unipolar depressive disorder and bipolar disorder is the presence of mania (or hypomania) in the course of the latter, significant differences between unipolar and bipolar depression have also been found in clinical studies. The primary aim of the present investigation was to assess pleasantness/unpleasantness ratings of chemosensory stimuli in depressed patients, including subjects with unipolar and bipolar depression. Sensory aspects (thresholds and identification abilities) of gustatory and olfactory function were also assessed. There were no major differences between a depression group, as a whole, and healthy controls in terms of gustatory and olfactory thresholds and identification abilities. Similarly, pleasantness ratings of various gustatory and olfactory stimuli did not differ between the control and depression group. Gustatory and olfactory thresholds and identification abilities did not differ between individuals with unipolar and bipolar depression. Bipolar patients tended to rate less gustatory stimuli as unpleasant and more olfactory stimuli as pleasant compared to unipolar patients. The present results suggest that: i) depression is not associated with any major deficit in sensory aspects of gustatory and olfactory function or altered hedonic ratings of chemosensory stimuli; ii) hedonic responses to chemosensory stimuli tend to be increased in bipolar as compared to unipolar depressed patients.

Treatment Outcome Predictors for Cocaine Dependence

Over the past decade, a large number of potential medications have been examined in clinical trials for cocaine dependence. Unfortunately, no effective pharmacotherapies for cocaine dependence have been found to date. Although effective treatments for cocaine dependence are still being investigated, a few variables have been found to significantly predict cocaine treatment response. These variables include cocaine use variables, such as days of cocaine use in the month before treatment, baseline urine cocaine results, and cocaine withdrawal symptoms. Comorbid depression and alcohol use have also been shown to be risk factors for relapse. Among personality variables, impulsivity and similar personality traits may predict treatment response. Initial promising findings with genetic polymorphism, brain activation, and stress response have also been found and need to be replicated in future studies.

Reduced sensitivity to the locomotor-stimulant effects of cocaine is associated with increased sensitivity to its discriminative stimulus properties

Outbred Long-Evans rats exhibit wide variation in their locomotor response to cocaine. Here, we investigated the relationship between these individual differences and interoceptive effects of cocaine in low cocaine responder (LCR) and high cocaine responder (HCR) phenotypes. Rats were trained to discriminate cocaine (10.0 mg/kg, intraperitoneally) from saline by repeated pairings of injections with one of two response levers. In subsequent tests for stimulus generalization to other cocaine doses (1.25-15.0 mg/kg), LCRs exhibited partial-to-full generalization at 1.85 and 2.5 mg/kg cocaine, respectively, whereas HCRs did not. When the selective 5-HT reuptake inhibitor fluoxetine (5.0 mg/kg) was coadministered with saline or different cocaine doses, we observed similar upward shifts in dose-response in both phenotypes. In contrast, coadministration of the 5-HT2A/2C agonist (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI; 0.3 mg/kg) led to partial substitution of DOI for cocaine and enhancement of the stimulus properties of 1.25 mg/kg cocaine in LCRs only. Finally, a retest of cocaine-induced locomotion after discrimination testing revealed marked behavioral sensitization in LCRs and modest changes in behavior in HCRs. Taken together, these results suggest that initial sensitivity to the locomotor-stimulant effects of cocaine is inversely related to its interoceptive properties and that differences in 5-HT systems may contribute to the phenotypic differences observed.

Meta-analysis of depression and substance use and impairment among cocaine users

BACKGROUND

The study evaluated, among cocaine users, the hypothesized positive association of depression and concurrent cocaine use and impairment, alcohol use and impairment, and general drug use and impairment. The hypothesis that gender would moderate these associations, with women showing a stronger correlation between depression and measures of substance use and impairment, was also tested. Also examined was the association of depression with future cocaine use and impairment and substance use treatment participation.

METHODS

Empirical reports on adult cocaine users published in English in peer-reviewed journals since 1986 that contained data on depression and substance use outcome(s) were obtained using a systematic search. Studies that placed restrictions on range of depression scores to select the sample, experiments that administered cocaine to subjects, and trials of antidepressant medications were excluded. The search yielded 60 studies for the analysis including 53 reports that collected data from clinical venues and seven that were community-based.

RESULTS

As hypothesized, the analyses showed that depression is associated with concurrent cocaine-, alcohol-, and general drug use and impairment. Effect sizes were small. Hypothesized moderating effects of gender were not supported. Depression was not associated, at a statistically significant level, with treatment participation or future cocaine use and impairment.

CONCLUSIONS

Depression is consistently but modestly associated with measures of cocaine-, alcohol-, and general drug use and impairment among cocaine users. Associations of depression with treatment participation and with future cocaine use and impairment are not immediately evident, although limitations of data warrant cautious interpretation.

Conditioned and sensitized responses to stimulant drugs in humans

In animal models considerable evidence suggests that increased motivation to seek and ingest drugs of abuse are related to conditioned and sensitized activations of the mesolimbic dopamine (DA) system. Direct evidence for these phenomena in humans, though, is sparse. However, recent studies support the following. First, the acute administration of drugs of abuse across pharmacological classes increases extracellular DA levels within the human ventral striatum. Second, individual differences in the magnitude of this response correlate with rewarding effects of the drugs and the personality trait of novelty seeking. Third, transiently diminishing DA transmission in humans decreases drug craving, the propensity to preferentially respond to reward-paired stimuli, and the ability to sustain responding for future drug reward. Finally, very recent studies suggest that repeated exposure to stimulant drugs, either on the street or in the laboratory, can lead to conditioned and sensitized behavioral responses and DA release. In contrast to these findings, though, in individuals with a long history of substance abuse, drug-induced DA release is decreased. This diminished DA release could reflect two different phenomena. First, it is possible that drug withdrawal related decrements in DA cell function persist longer than previously suspected. Second, drug-paired stimuli may gain marked conditioned control over the release of DA and the expression of sensitization leading to reduced DA release when drug-related cues are absent. Based on these observations a two-factor hypothesis of the role of DA in drug abuse is proposed. In the presence of drug cues, conditioned and sensitized DA release would occur leading to focused drug-seeking behavior. In comparison, in the absence of drug-related stimuli DA function would be reduced, diminishing the ability of individuals to sustain goal-directed behavior and long-term objectives. This conditioned control of the expression of sensitized DA release could aggravate susceptibility to relapse, narrow the range of interests and perturb decision-making, accounting for a wide range of addiction related phenomena.

Avaliando a motivação para mudança em dependentes de cocaína

O objetivo desta pesquisa foi estudar a motivação para a mudança em indivíduos internados por dependência de cocaína através de um delineamento transversal e correlacional. A amostra era composta por 70 indivíduos de ambos os sexos, idade média de 28,67 anos. Foram utilizados os seguintes instrumentos: Escala de Intensidade de Dependência de Cocaína, Beck Depression Inventory, Beck Anxiety Inventory da University of Rhode Island Change Assessment. A intensidade da dependência de cocaína foi avaliada como leve para 15,7% da amostra, moderada para 54,3% e grave para 30%. A média dos escores do Beck Anxiety Inventory foi 11,39 pontos e do Beck Depression Inventory 17,31 pontos. As médias dos escores nas subescalas da University of Rhode Island Change Assessment foram: 17,03 na pré-contemplação, 35,63 na contemplação, 35,10 na ação e 38,33 na manutenção. Encontrou-se uma correlação significativa entre os sintomas de depressão e a ansiedade e a gravidade da dependência, sugerindo que os indivíduos com grau de dependência mais elevado possuíam maior intensidade de sintomas de depressão e ansiedade.

Desipramine treatment of cocaine-dependent patients with depression: a placebo-controlled trial

OBJECTIVE

The aim of this study was to test the hypothesis that desipramine would be an effective treatment in cocaine abusers with current depressive disorders.

METHOD

This was a randomized, 12-week, double-blind, 'placebo-controlled trial of outpatients (N = 111) meeting DSM-III-R criteria for cocaine dependence and major depression or dysthymia (by SCID interview). Participants were treated with desipramine, up to 300 mg per day, or matching placebo. All patients received weekly individual manual-guided relapse prevention therapy. Weekly outcome measures included the Clinical Global Impression Scale, self-reported cocaine use and craving, urine toxicology, and the Hamilton Depression Scale (biweekly). Summary measures of mood and cocaine use outcome were compared between treatment groups with chi2- or t-tests. Dichotomous summary measures of depression response and cocaine response were the primary outcomes. Mixed effect models were also fit to explore the relationship of cocaine use to mood improvement and treatment over weeks in the trial.

RESULTS

Desipramine was associated with a higher rate of depression response (51%, 28/55) than placebo (32%, 18/56) (p < 0.05), but treatment groups did not differ in rate of cocaine response. Depression improvement was associated with improvement in cocaine use. Desipramine was associated with more dropouts due to side effects and medical adverse events, while placebo was associated with more dropouts due to psychiatric worsening.

CONCLUSIONS

Desipramine was an effective treatment for depression among cocaine-dependent patients. Improvement in mood was associated with improvement in cocaine abuse, but a direct effect of medication on cocaine outcome was not clearly established and rates of sustained abstinence were low. Future research should examine newer antidepressant medications with more benign side effect profiles and combinations of behavioral and pharmacological treatments to maximize effects on cocaine use.

Treatment of co-occurring alcohol, drug, and psychiatric disorders

Comorbid psychiatric disorders and drug use disorders (DUDs) are common among adolescents with alcohol use disorders (AUDs). These comorbid disorders have a large potential significance on the clinical course of the AUDs among adolescents, and can predict a shorter time to relapse of alcohol use. The use of medication for treatment of the various comorbid adolescent populations has increased dramatically in recent years, despite the lack of double-blind, placebo-controlled studies that demonstrate their safety and efficacy. Consequently, to date, no empirically proven treatment exists for most of these comorbid disorders. This chapter reviews the state of the art regarding the treatment of comorbid adolescents. This chapter also identifies gaps in knowledge regarding the treatment of comorbid adolescents, and outlines directions for future research in this field.

Blunted response to cocaine in the Flinders hypercholinergic animal model of depression

The Flinders sensitive line (FSL) rat is a proposed genetic hypercholinergic animal model of human depression. Considering the strong comorbidity between depression and cocaine dependence we investigated the well-documented behavioral and molecular effects of cocaine in the FSL and their control Flinders resistant line (FRL) rats. First, we found no difference between the two lines to establish cocaine self-administration; both lines reached stable responding within 10 days of training at a fixed ratio-1 schedule of reinforcement (1.5 mg/kg/injection). However, the FSL rats exhibited reduced cocaine intake at a dose of 0.09 mg/kg/injection in a within-session dose-response curve (0.02, 0.09, 0.38, 1.5 mg/kg/injection). Second, we examined the effects of repeated cocaine administration on locomotor activity, dopamine overflow and striatal prodynorphin mRNA expression. We found the FSL rats to be low responders to novelty and to exhibit less locomotor activation after repeated cocaine administration (30 mg/kg, i.p., daily injections for 10 days) than their controls. Microdialysis sampling from the nucleus accumbens shell revealed no significant difference in the dopamine overflow between the rat lines, neither during baseline nor after cocaine stimulation. Postmortem analyses of striatal prodynorphin mRNA expression (using in situ hybridization histochemistry) revealed a differentiated response to the cocaine exposure. In contrast to control FRL rats, the FSL rats showed no typical cocaine-evoked elevation of prodynorphin mRNA levels in rostral subregions of the striatum whereas both strains expressed increased prodynorphin mRNA levels in the caudal striatum after cocaine administration. In conclusion, the FSL animal model of depression demonstrates marked blunting of the locomotor and dynorphin neuroadaptative responses to cocaine in accordance with its enhanced cholinergic sensitivity.

Treatment of cocaine dependence and depression

In common with all other classes of substance use disorders, cocaine dependence has been shown to be strongly associated with depression by community and clinical surveys. Diagnosing depression in cocaine abusers can be challenging because it is difficult to distinguish transient symptoms caused by cocaine from enduring depression syndromes. Nonetheless, both "substance-induced" and "independent" depression syndromes require clinical attention, especially when symptoms have been persistent and severe before entering treatment. Use of antidepressant medications for combined cocaine dependence and depression is supported by a preponderance of evidence from 4 randomized clinical trials (RCTs) that prospectively targeted both depression and cocaine dependence and 7 RCTs in which a post hoc analyses demonstrated efficacy in the subgroup of cocaine abusers with comorbid depression. Notably, most negative studies have evaluated SSRIs while positive studies have used agents such as desipramine or buproprion. A substantial clinical trials literature supports the efficacy of behavioral treatments for general populations of cocaine abusers and of patients with depression but few studies have addressed patients with both disorders. Treatment development and research are needed on models of care that truly integrate strategies for addressing both cocaine use and depression. Recent advances have paved the way for a new generation of research. These include validation of efficacious cocaine treatments, improved diagnostic methods, organization of the Clinical Trials Network and development of guidelines for managing methodological challenges posed by high rates of current medication use and polysubstance abuse in treatment entering cocaine abusers.

Recent advances in the pharmacotherapy of cocaine dependence

The pharmacotherapy of cocaine dependence is a rapidly developing field of research that may soon produce efficacious medications. Expanding research on reward-related brain circuitry, which is acutely activated and chronically dysregulated by cocaine, has helped reveal the neurobiological features of cocaine dependence and is guiding pharmacologic strategies that have significant potential to improve clinical outcome. Cocaine dependence is a multifaceted disorder with distinct clinical components that may respond to different pharmacologic approaches. Pharmacologic strategies for this disorder include blocking euphoria, reducing withdrawal and negative mood symptoms, ameliorating craving, and enhancing the prefrontal cortical function that seems to be impaired in cocaine-dependent patients. One medication may not be sufficient to treat these diverse elements of cocaine dependence because preliminary studies report efficacy with medications that have opposite actions on reward-related circuits. This review highlights pertinent advances in cocaine neurobiology, recent clinical trials, and controversies in the pharmacologic treatment of cocaine dependence.

Die neuropsychologischen Effekte von Kokain

Zusammenfassung: Kokainkonsumenten sind in der Regel entweder Gelegenheitskonsumenten mit geringem und relativ gut kontrollierbarem Kokainkonsum oder Kokainabhängige, die exzessiv große Mengen Kokain einnehmen (Binge-Taking). Neuropsychologische Untersuchungen bei Gelegenheitskonsumenten mit kleinen bis mittleren Kokaindosen, die geeignet sind, “Euphorie” und “Hochgefühle” auszulösen, ergaben bisher keine Hinweise auf neuropsychologische Funktionsbeeinträchtigungen in der akuten Phase. Vielmehr wurden in der akuten Kokainphase verbesserte Aufmerksamkeitsleistungen und schnellere Reaktionszeiten gemessen, die bis zum Beginn der postakuten Phase anhielten. Explizite Untersuchungen zur postakuten Phase oder Studien über die Effekte von Kokain in einem hohen Dosisbereich liegen derzeit nicht vor. Kokainabhängige weisen in einem Abstinenzzeitraum von bis zu mindestens 3 Monaten neuropsychologische, neurologische und unter Umständen auch psychiatrische Defizite auf. Deutliche Defizite abstinenter Kokainabhängiger wurden bei der Aufmerksamkeitsleistung, der Konzentration, der inhibitorischen Kontrolle und im Gedächtnis gefunden, wobei die verschiedenen Gedächtnistypen unterschiedlich betroffen sind. Kommt es bei Kokainabhängigen zu einer erneuten Kokaineinnahme, d.h. zu einer Binge-Phase, so ist unmittelbar danach in der so genannten Crash-Phase noch zusätzlich mit zum Teil schweren emotional-motivationalen Beeinträchtigungen zu rechnen.

Comorbid Major Depressive Disorder as a Prognostic Factor in Cocaine‐Abusing Buprenorphine‐Maintained Patients Treated with Desipramine and Contingency Management

Depression is common among patients who abuse both opiates and cocaine, and its treatment has had mixed success. This study compares buprenorphine-maintained patients with lifetime major depressive disorder (MDD, N = 53) with those never depressed (ND, N = 96) on cocaine and opiate-free urines during a 12-week outpatient double-blind, placebo-controlled, randomized clinical trial. The 149 subjects were assigned to four groups: 1) desipramine (DMI) + contingency management (CM); 2) DMI + noncontingency management (NCM); 3) placebo + CM; and 4) placebo + NCM. Depression assessments included Hamilton Depression Rating Scale, Center for Epidemiological Studies Depression Inventory, and Structured Clinical Interview for DSM-IV interview for diagnosis of lifetime MDD. Urine toxicologies were performed thrice weekly and the CES-D was performed monthly. The MDD group had a larger proportion of females (45% vs 21%, P = 0.02) and were more likely to be married (13.2% vs 7.3%, P = 0.02) than the ND group. Treatment retention did not vary by depression status. Hierarchical Linear Modeling found that depressive symptoms decreased comparably across the four treatment groups. Although participation in CM improved drug-free urines more for patients with MDD than for the ND group (Z = 2.44, P = 0.01), treatment with DMI was significantly more efficacious for the ND group than for the MDD group (Z = -2.89, P = 0.003). These results suggest that patients with MDD may respond better to behavioral treatments such as CM than to desipramine plus buprenorphine. The ND cocaine-abusing, opiate-dependent patients may be more responsive to the anticraving effects of DMI.

Association of cocaine withdrawal symptoms with more severe dependence and enhanced subjective response to cocaine

The purpose of this two part study was to better characterize cocaine users based on self-reported cocaine withdrawal symptoms by examining screening data and response to smoked cocaine in the human laboratory. The first study sample included male and female non-treatment seeking cocaine users who were screened as potential subjects for inpatient studies. Of the 555 subjects, 462 (82%) endorsed symptoms consistent with DSM-IV criteria for cocaine withdrawal. Cocaine users who met criteria for cocaine withdrawal, compared with those who did not, reported a significantly higher amount of cocaine use and a history of medical and psychosocial problems. Cocaine users meeting DSM-IV withdrawal criteria, which included endorsement of depression, were also more likely to have a history of depression, to have seriously considered suicide, and to have had chemical dependency treatment even when amount spent on cocaine was covaried. The second study sample, which was a subset of Study I, included those who participated in human cocaine studies following the phone screening. Cocaine users who met criteria for cocaine withdrawal (n=34), compared with those who did not (n=10), had enhanced subjective ratings of 'high' and 'feel the effect of last dose' in response to a single delivery of 0.4 mg/kg of smoked cocaine. These results suggest that history of cocaine withdrawal symptoms may be associated with enhanced cocaine responses and greater severity of cocaine dependence.

Training primary health care professionals to provide buprenorphine and LAAM treatment

This paper describes the development and implementation of training programs for primary care medical practitioners and pharmacists in the delivery of buprenorphine and LAAM treatment in the management of opiate dependence. Separate training programs were developed for each medication. Each training package included learning objectives, training materials, and assessment instruments. Findings of the evaluation of these initiatives and the subsequent Australian postregistration training program for buprenorphine are described.