Altered levels of sex and stress steroid hormones assessed daily over a 28-day cycle in early abstinent cocaine-dependent females

Sex/Gender Differences in the Time-Course for the Development of Substance Use Disorder: A Focus on the Telescoping Effect

Sex/gender effects have been demonstrated for multiple aspects of addiction, with one of the most commonly cited examples being the "telescoping effect" where women meet criteria and/or seek treatment of substance use disorder (SUD) after fewer years of drug use as compared with men. This phenomenon has been reported for multiple drug classes including opioids, psychostimulants, alcohol, and cannabis, as well as nonpharmacological addictions, such as gambling. However, there are some inconsistent reports that show either no difference between men and women or opposite effects and a faster course to addiction in men than women. Thus, the goals of this review are to evaluate evidence for and against the telescoping effect in women and to determine the conditions/populations for which the telescoping effect is most relevant. We also discuss evidence from preclinical studies, which strongly support the validity of the telescoping effect and show that female animals develop addiction-like features (e.g., compulsive drug use, an enhanced motivation for the drug, and enhanced drug-craving/vulnerability to relapse) more readily than male animals. We also discuss biologic factors that may contribute to the telescoping effect, such as ovarian hormones, and its neurobiological basis focusing on the mesolimbic dopamine reward pathway and the corticomesolimbic glutamatergic pathway considering the critical roles these pathways play in the rewarding/reinforcing effects of addictive drugs and SUD. We conclude with future research directions, including intervention strategies to prevent the development of SUD in women. SIGNIFICANCE STATEMENT: One of the most widely cited gender/sex differences in substance use disorder (SUD) is the "telescoping effect," which reflects an accelerated course in women versus men for the development and/or seeking treatment for SUD. This review evaluates evidence for and against a telescoping effect drawing upon data from both clinical and preclinical studies. We also discuss the contribution of biological factors and underlying neurobiological mechanisms and highlight potential targets to prevent the development of SUD in women.

Therapeutics for Substance-Using Women: The Need to Elucidate Sex-Specific Targets for Better-Tailored Treatments

In the last decade, alcohol consumption in the US has risen by 84% in women compared with 35% in men. Furthermore, research has shown that sex- and gender-related differences may disadvantage women in terms of developing a range of psychological, cognitive, and medical problems considerably earlier in their drinking history than men, and despite consuming a similar quantity of substances. While this "telescoping" process has been acknowledged in the literature, a concomitant understanding of the underlying biobehavioral mechanisms, and an increase in the development of specific treatments tailored to women, has not occurred. In the current chapter we focus on understanding why the need for personalized, sex-specific medications is imperative, and highlight some of the potential sex-specific gonadal and stress-related adaptations underpinning the accelerated progress from controlled to compulsive drug and alcohol seeking in women. We additionally discuss the efficacy of these mechanisms as novel targets for medications development, using exogenous progesterone and guanfacine as examples. Finally, we assess some of the challenges faced and progress made in terms of developing innovative medications in women. We suggest that agents such as exogenous progesterone and adrenergic medications, such as guanfacine, may provide some efficacy in terms of attenuating stress-induced craving for several substances, as well as improving the ability to emotionally regulate in the face of stress, preferentially in women. However, to fully leverage the potential of these therapeutics in substance-using women, greater focus needs to the placed on reducing barriers to treatment and research by encouraging women into clinical trials.

The influence of sex and reproductive cycle on cocaine-induced behavioral and neurobiological alterations: a review

This systematic review (SR) was aimed at answering two questions: (1) how sex and ovarian hormones alter behavior associated with cocaine use; (2) which possible neurobiological mechanisms explain behavioral differences. Three different researchers conducted a search in PUBMED for all kinds of articles published between the years of 1991 to 2021 on the theme "reproductive cycle and cocaine", "estrous cycle and cocaine", "menstrual cycle and cocaine", "fluctuation of ovarian hormones and cocaine", "estrogen and cocaine" and "progesterone and cocaine". Sixty original studies were identified and subdivided into experimental rodent studies and clinical trials. Experimental studies were characterized by author/year, species/strain, sex/number, age/weight, dose/route/time of administration, hormonal assessment, or administration. Clinical trials were characterized by author/year, sex/number, age, exclusion criterion, dose/route of administration/time of cocaine, and hormonal assessment. Results gathered showed that rodent females develop increased consumption, seeking behavior, craving, relapse, locomotion, increases in stress and anxiety, among other behavioral alterations during peaks of estrogen. These observations are related to the direct effects played by ovarian hormones (in particularly estradiol), in dopamine, but also in serotonin neurons, and in brain regions such as the tegmental area, the nucleus accumbens, the hypothalamus, the amygdala and the prefrontal cortex. Increased sensitization to cocaine presented by high estradiol females was linked to the activation of a CBR1-mediated mechanism and GABA-A-dependent suppression of inhibitory synaptic activity of the prelimbic prefrontal cortex. Estradiol facilitation of cocaine-increased locomotion and self-administration was shown to require the release of glutamate and the activation of metabotropic glutamate receptors subtype 5. Clinical studies also tend to point to a stimulatory effect of estradiol on cocaine sensitization and a neuroprotective effect of progesterone. In conclusion, the results of the present review indicate a need for further preclinical and clinical trials and neurobiological studies to better understand the relationship between sex and ovarian hormones on cocaine sensitization.

HPA axis activity across the menstrual cycle - a systematic review and meta-analysis of longitudinal studies

Differential HPA axis function has been proposed to underlie sex-differences in mental disorders; however, the impact of fluctuating sex hormones across the menstrual cycle on HPA axis activity is still unclear. This meta-analysis investigated basal cortisol concentrations as a marker for HPA axis activity across the menstrual cycle. Through a systematic literature search of five databases, 121 longitudinal studies were included, summarizing data of 2641 healthy, cycling participants between the ages of 18 and 45. The meta-analysis showed higher cortisol concentrations in the follicular vs. luteal phase (d_SMC = 0.12, p =.004, [0.04 - 0.20]). Comparisons between more precise cycle phases were mostly insignificant, aside from higher concentrations in the menstrual vs. premenstrual phase (d_SMC = 0.17, [0.02 - 0.33], p =.03). In all included studies, nine samples used established cortisol parameters to indicate HPA axis function, specifically diurnal profiles (k = 4) and the cortisol awakening response (CAR) (k = 5). Therefore, the meta-analysis highlights the need for more rigorous investigation of HPA axis activity and menstrual cycle phase.

Is Illicit Substance Use Gender-Specific? The Basic Points of Mental and Health Disorders

Among the groups of users of illicit substances, a high percentage are persons deprived of their liberty; at the same time, each social and age group is also affected, to one degree or another. The purpose of this study is to provide general data on the relationship between different psychostimulants, clinical and socio-demographic studies, and gender, both among the general population and in one of the most at-risk groups. This review identifies the use of illicit substances as gender-specific in the general population. A detailed study of the causal relationship between the use of illicit substances and gender was carried out. Electronic databases Academic Search Complete, PubMed, HealthCare, Web of Science, and Google Scholar were searched for relevant studies up to 2022 associated with drug abuse and mental and health disorders. The analysis indicated that the human population showed significant differences between the sex of the consumer as to the type of drug consumers, development of addiction, and relapse. We focus on the pathological changes caused by drug use, the personal and physiological individual traits that influence drug choice, and the extent of use in one of the most affected groups of individuals. The study may provide some guidance in developing gender-specific treatment and prevention, including response to some pharmacological and behavioral therapies. The review is intended for a wide audience of social workers, toxicologists, and pharmacologists.

Sex- and Dose-Dependent Differences in the Development of an Addiction-Like Phenotype Following Extended-Access Fentanyl Self-Administration

Opioid use disorder (OUD) is a major epidemic in the United States, and fentanyl is a major culprit. The National Institute on Drug Abuse has highlighted an urgent need for research on the risks and outcomes of OUD with fentanyl; a better understanding of sex/gender differences is also critically needed given that the opioid epidemic has been particularly impactful on women. In response to this need, we developed a rat model of OUD with fentanyl and showed that sex impacts relapse vulnerability following extended-access self-administration under a low fentanyl dose. Here, our goal was to determine sex differences across a broad dose range, including high doses expected to maximize the expression of addiction-like features (e.g., vulnerability to relapse and physical dependence). Male and female rats were assigned to self-administer one of four fentanyl doses (0.25, 0.75, 1.5, and 3.0 µg/kg/infusion), and once they acquired, they were given extended (24-h/day), intermittent access (2, 5 min trials/h, fixed-ratio 1) to fentanyl for 10 days. Physical dependence (spontaneous weight loss) was assessed during early withdrawal, and relapse vulnerability was assessed on withdrawal day 15 using an extinction/cue-induced reinstatement procedure. Despite markedly higher intake in the high- versus low-dose groups, each group responded similarly during relapse testing (extinction and cue-induced reinstatement). However, number of infusions, or frequency of use, during extended access was predictive of later vulnerability to relapse, whereas total intake impacted physical dependence given that weight loss only occurred following the discontinuation of fentanyl self-administration at the three highest doses. Females self-administered more fentanyl each day and within each binge (active trial), and had longer lasting weight loss during withdrawal than males. Relapse vulnerability was also higher in females than males and highest in females tested during estrus. These findings indicate that sex is an important risk factor for patterns and levels of fentanyl intake, relapse, and physical dependence, and while fentanyl intake predicts physical dependence, frequency of use predicts relapse.

Sex Differences in Opioid and Psychostimulant Craving and Relapse: A Critical Review

A widely held dogma in the preclinical addiction field is that females are more vulnerable than males to drug craving and relapse. Here, we first review clinical studies on sex differences in psychostimulant and opioid craving and relapse. Next, we review preclinical studies on sex differences in psychostimulant and opioid reinstatement of drug seeking after extinction of drug self-administration, and incubation of drug craving (time-dependent increase in drug seeking during abstinence). We also discuss ovarian hormones' role in relapse and craving in humans and animal models and speculate on brain mechanisms underlying their role in cocaine craving and relapse in rodent models. Finally, we discuss imaging studies on brain responses to cocaine cues and stress in men and women.The results of the clinical studies reviewed do not appear to support the notion that women are more vulnerable to psychostimulant and opioid craving and relapse. However, this conclusion is tentative because most of the studies reviewed were correlational, not sufficiently powered, and not a priori designed to detect sex differences. Additionally, imaging studies suggest sex differences in brain responses to cocaine cues and stress. The results of the preclinical studies reviewed provide evidence for sex differences in stress-induced reinstatement and incubation of cocaine craving but not cue- or cocaine-induced reinstatement of cocaine seeking. These sex differences are modulated in part by ovarian hormones. In contrast, the available data do not support the notion of sex differences in craving and relapse/reinstatement for methamphetamine or opioids in rodent models. SIGNIFICANCE STATEMENT: This systematic review summarizes clinical and preclinical studies on sex differences in psychostimulant and opioid craving and relapse. Results of the clinical studies reviewed do not appear to support the notion that women are more vulnerable to psychostimulant and opioid craving and relapse. Results of preclinical studies reviewed provide evidence for sex differences in reinstatement and incubation of cocaine seeking but not for reinstatement or incubation of methamphetamine or opioid seeking.

A Gender Perspective of Addictive Disorders

Purpose of Review

Substance use disorders (SUD) affect differentially women and men. Although the prevalence has been reported higher in men, those women with addictive disorders present a more vulnerable profile and are less likely to enter treatment than men. The aim of this paper is to present an overview of how sex and gender may influence epidemiology, clinical manifestations, social impact, and the neurobiological basis of these differences of women with SUD, based on human research.

Recent Findings

The differences in prevalence rates between genders are getting narrower; also, women tend to increase the amount of consumption more rapidly than men, showing an accelerated onset of the SUD (telescoping effect). In respect to clinical features, the most important differences are related to the risk of experience psychiatric comorbidity, the exposure to intimate partner violence, and the associated high risks in sexual and reproductive health; and those who are mothers and addicted to substances are at risk of losing the custody of children accumulating more adverse life events. Some of these differences can be based on neurobiological differences: pharmacokinetic response to substances, sensitivity to gonadal hormones, differences in neurobiological systems as glutamate, endocannabinoids, and genetic differences.

Summary

Specific research in women who use drugs is very scarce and treatments are not gender-sensitive oriented. For these reasons, it is important to guarantee access to the appropriate treatment of women who use drugs and a need for a gender perspective in the treatment and research of substance use disorders.

Maternal adverse childhood experiences and postpartum depressive symptoms in young, low-income women

OBJECTIVES

Exposure to adverse childhood experiences (ACEs), such as child maltreatment and family dysfunction, is highly prevalent. Previous research has shown an association between ACEs and adult depression. The aim of the current study was to expand the existing literature by testing the association between ACEs and postpartum depression (PPD) symptoms in an urban, ethnically diverse sample of women.

METHODS

Participants (N = 746; ages 18-47; mean age = 27.3) were recruited at a large, urban university medical center as part of the Longitudinal Infant and Family Environment (LIFE) study. The association between ACEs and PPD symptoms were tested via hierarchical linear regression models.

RESULTS

The majority of the participants (61%) reported experiencing at least one type of ACEs prior to age 18. ACEs were positively associated with PPD symptoms (β = .29, p < .001), controlling for maternal race/ethnicity, age, educational attainment, marital status, household income, and infant gender and birth order.

CONCLUSIONS

The results showed that exposure to ACEs was related to PPD symptoms among low-income women. Screenings for ACEs during prenatal checkups may help identify women at risk of depression and facilitate timely prevention and treatment efforts.

Circadian rhythms and substance use disorders: A bidirectional relationship

The circadian system organizes circadian rhythms (biological cycles that occur around 24 h) that couple environmental cues (zeitgebers) with internal functions of the organism. The misalignment between circadian rhythms and external cues is known as chronodisruption and contributes to the development of mental, metabolic and other disorders, including cancer, cardiovascular diseases and addictive disorders. Drug addiction represents a global public health concern and affects the health and well-being of individuals, families and communities. In this manuscript, we reviewed evidence indicating a bidirectional relationship between the circadian system and the development of addictive disorders. We provide information on the interaction between the circadian system and drug addiction for each drug or drug class (alcohol, cannabis, hallucinogens, psychostimulants and opioids). We also describe evidence showing that drug use follows a circadian pattern, which changes with the progression of addiction. Furthermore, clock gene expression is also altered during the development of drug addiction in many brain areas related to drug reward, drug seeking and relapse. The regulation of the glutamatergic and dopaminergic neurocircuitry by clock genes is postulated to be the main circadian mechanism underlying the escalation of drug addiction. The bidirectional interaction between the circadian system and drug addiction seems to be mediated by the effects caused by each drug or class of drugs of abuse. These studies provide new insights on the development of successful strategies aimed at restoring/stabilizing circadian rhythms to reduce the risk for addiction development and relapse.

Hypothalamic-pituitary-adrenal axis activity in post-traumatic stress disorder and cocaine use disorder

Post-traumatic stress disorder (PTSD) is often comorbid with cocaine use disorder (CUD), but little is known about hypothalamic-pituitary-adrenal (HPA) axis function in PTSD + CUD. Here we review the clinical and pre-clinical literature of PTSD and CUD with the goal of generating hypotheses about HPA axis activity in comorbid PTSD + CUD. Low glucocorticoid (CORT) levels immediately after trauma exposure are associated with PTSD. CORT administered within 12 h of trauma exposure reduces later PTSD symptoms. Weeks-years after trauma, meta-analyses find lower CORT levels in patients with PTSD relative to never-traumatized controls; the same is found in a pre-clinical model of PTSD. In rodents, reduced basal CORT levels are consistently found after chronic cocaine self-administration. Conversely, increased CORT levels are found in CUD patients during the first 2 weeks of cocaine abstinence. There is evidence for CORT hyper-suppression after dexamethasone, high glucocorticoid receptor (GR) number pre-trauma, and increased GR translocation to the nucleus in PTSD. Hyper-suppression of HPA axis activity after dexamethasone suggests that PTSD individuals may have increased anterior pituitary GR. Given evidence for decreased anterior pituitary GR in rats that self-administer cocaine, PTSD + CUD individuals may have normal GR density and low basal CORT levels during late abstinence. Future studies should aim to reconcile the differences in pre-clinical and clinical basal CORT levels during cocaine and assess HPA axis function in both rodent models of CUD that consider stress-susceptibility and in PTSD + CUD individuals. Although additional studies are necessary, individuals with PTSD + CUD may benefit from behavioral and psychopharmacological treatments to normalize HPA axis activity. LAY SUMMARY Post-traumatic stress disorder (PTSD) is often comorbid with cocaine use disorder (CUD), but little is known about the hypothalamic-pituitary-adrenal (HPA) axis function in PTSD + CUD. The current review provides a synthesis of available clinical and pre-clinical data on PTSD and CUD with the goal of generating hypotheses about HPA axis activity in comorbid PTSD + CUD. While this review finds ample evidence supporting aberrant HPA axis activity in both PTSD and CUD, it suggests that more research is needed to understand the unique changes HPA axis activity in PTSD + CUD, as well as the bidirectional relationship between stress-susceptibility and motivation to seek cocaine.

Gender differences in subjective stress and neuroendocrine response to a stress task among individuals with opioid dependence: A pilot study

BACKGROUND

Opioid dependence is a significant public health problem in the United States and the number of opioid overdose deaths among women has increased dramatically in comparison to men in the last few years. In this context, understanding the biological mechanisms underlying gender differences in vulnerability to opioid dependence is essential.

METHODS

The current pilot study examined gender differences in subjective stress, heart rate (HR), and cortisol/dephydroepiandrosterone (DHEA) response to a laboratory stressor (Trier Social Stress Test; TSST) or a no-stress condition, and drug cue paradigm among men (n = 21) and women (n = 18) with opioid dependence.

RESULTS

Significant group (TSST vs. no stress) differences emerged in self-reported stress [F(1,35) = 23.8, p < .001], HR [F(1,31) = 12.3; p = .001] and cortisol (F_1,34 = 5.0; p = .032) response, such that the TSST group was more reactive than the no-stress group. Women reported greater subjective stress [F(1,35) = 6.5, p <= .015] in response to the TSST compared to men. However, men evidenced marginally greater cortisol and DHEA responses to the TSST compared to women [F(1,34) = 2.7; p = .113 and F(1,31) = 3.4; p = .073, respectively].

CONCLUSIONS

Although women with opioid dependence reported greater subjective stress when exposed to a laboratory stress paradigm as compared to men, the neuroendocrine response was more robust in men. This pattern was similar to gender findings in men and women with cocaine and tobacco use disorders. The blunted cortisol combined with an increased subjective response among women may be a sign of HPA axis dysregulation which could increase vulnerability to relapse in women.

Sex differences in daily life stress and craving in opioid-dependent patients

BACKGROUND

Responses to stress and drug craving differ between men and women. Differences in the momentary experience of stress in relation to craving are less well-understood.

OBJECTIVES

Using ecological momentary assessment (EMA), we examined sex differences in real-time in two areas: (1) causes and contexts associated with stress, and (2) the extent to which stress and drug cues are associated with craving.

METHODS

Outpatients on opioid-agonist treatment (135 males, 47 females) reported stress, craving, and behavior on smartphones for 16 weeks. They initiated an entry each time they felt more stressed than usual (stress event) and made randomly prompted entries 3 times/day. In stress-event entries, they identified the causes and context (location, activity, companions), and rated stress and craving severity.

RESULTS

The causes reported for stress events did not differ significantly by sex. Women reported arguing and being in a store more often during stress events, and men reported working more often during stress events, compared to base rates (assessed via random prompts). Women showed a greater increase in opioid craving as a function of stress (p < 0.0001) and had higher stress ratings in the presence of both stress and drug cues relative to men (p < 0.01). Similar effects were found for cocaine craving in men (p < 0.0001).

CONCLUSION

EMA methods provide evidence based on real-time activities and moods that opioid-dependent men and women experience similar contexts and causes for stress but differ in stress- and cue-induced craving. These findings support sex-based tailoring of treatment, but because not all participants conformed to the overall pattern of sex differences, any such tailoring should also consider person-level differences.

Sex differences in guanfacine effects on stress-induced stroop performance in cocaine dependence

AIMS

Chronic drug abuse leads to sex-specific changes in drug cue and stress physiologic and neuroendocrine reactivity as well as in neural responses to stress and cue-related challenges and in executive function such as inhibitory control, cognitive flexibility and self control. Importantly, these functions have been associated with high risk of relapse and treatment. Alpha-2 agonism may enhance inhibitory cognitive processes in the face of stress with sex-specific effects, however this has not been previously assessed in cocaine dependence.

METHOD

Forty inpatient treatment-seeking cocaine dependent individuals (13F/27M) were randomly assigned to receive either placebo or up to 3mgs of Guanfacine. Three laboratory sessions were conducted following 3-4 weeks of abstinence, where patients were exposed to three 10-min personalized guided imagery conditions (stress, drug cue, combined stress/cue), one per day, on consecutive days in a random, counterbalanced order. The Stroop task was administered at baseline and immediately following imagery exposure.

RESULTS

Guanfacine treated women improved their performance on the Stroop task following exposure to all 3 imagery conditions compared with placebo women (p=0.02). This improvement in cognitive inhibitory performance was not observed in the men.

CONCLUSIONS

Enhancing the ability to cognitively regulate in the face of stress, drug cues and combined stress and drug cue reactivity may be key targets for medications development in cocaine dependent women.

Effects of crack cocaine addiction and stress-related genes on peripheral BDNF levels

This study examined the effects of glucocorticoid receptor (NR3C1), corticotropin-releasing hormone receptor 1 (CRHR1), and brain-derived neurotrophic factor (BDNF) genes on susceptibility to crack cocaine addiction and BDNF levels. Crack addicted patients who sought treatment (n = 280) and non-addicted individuals (n = 241) were assessed. Three SNPs in NR3C1 (rs6198, rs41423247, and rs10052957), three in CRHR1 (rs12944712, rs110402, and rs878886), and one in BDNF (rs6265) were genotyped. No significant effect was seen in the case-control analyses. Crack cocaine addicted patients showed significantly lower serum BDNF levels. Significant effects were observed for NR3C1 rs41423247 and rs10052957. These effects were restricted to non-addicted individuals and they were supported by significant gene-by-disease status interactions. For CRHR1, all SNPs were associated with BDNF levels. Although there were significant effects only in the analysis restricted to non-addicted individuals, the lack of significant results in the gene-by-disease status interaction analyses suggest a general effect on BDNF levels. The haplotype analyses presented the same effect seen in the single marker analyses. This study suggests that SNPs in the NR3C1 and CRHR1 genes may influence BDNF levels, but this effect is blunted in the context of crack cocaine addiction. Therefore, our data may be interpreted in light of several studies showing pronounced effects of crack cocaine on BDNF levels. Since peripheral BDNF is a biomarker for several psychiatric phenotypes, our results may be useful in interpreting previous associations between stress-related SNPs, drug addiction, and depression.

Alcohol, stress, and glucocorticoids: From risk to dependence and relapse in alcohol use disorders

In this review, we detail the clinical evidence supporting the role of psychological and physiological stress in instrumental motivation for alcohol consumption during the development of mild to moderate alcohol use disorders (AUDs) and in the compulsive, habitual alcohol consumption seen in severe, chronic, relapsing AUDs. Traditionally, the study of AUDs has focused on the direct and indirect effects of alcohol on striatal dopaminergic pathways and their role in the reinforcing effects of alcohol. However, growing evidence also suggests that alcohol directly stimulates the hypothalamic pituitary adrenal (HPA) axis and has effects on glucocorticoid receptors in extrahypothalamic, limbic forebrain, and medial Prefrontal Cortex (PFC) circuits, which contribute to the development of AUDs and their progression in severity, chronicity, and relapse risk. Evidence indicates HPA axis, glucocorticoid, and PFC dysfunction during protracted withdrawal and under high arousal conditions in those with severe AUDs, and novel evidence is also emerging to suggest HPA axis dysfunction with binge/heavy drinking, which is associated with motivation for alcohol in non-dependent individuals. Specifically, alcohol-associated alterations in HPA axis responses to stress and alcohol cues may serve as interoceptive physiological signals and facilitate conditioning mechanisms to influence alcohol motivation. Thus, this dysfunction may serve as a potential biomarker of both risk and of relapse. Based on this emerging data, we conceptualize and present early evidence for treatment targets that may improve PFC function and/or normalize HPA axis functioning and may be beneficial in the treatment and relapse prevention of AUDs. Finally, we suggest that individual differences in alcohol-related pathophysiology in these circuits may modulate treatment and recovery response, thereby supporting the need for building personalized medicine algorithms to understand and treat AUDs. This article is part of the Special Issue entitled "Alcoholism".

Acute intermittent porphyria symptoms during the menstrual cycle

BACKGROUND

Acute intermittent porphyria (AIP), a life-threatening form of the disease, is accompanied by several pain, mental and physical symptoms.

AIMS

In this study, we evaluated the cyclicity of AIP and premenstrual syndrome (PMS) symptoms in 32 women with DNA-diagnosed AIP during their menstrual cycles, in northern Sweden.

METHODS

The cyclicity of AIP symptoms and differences in them between the follicular and luteal phases, and the cyclicity of each symptom in each individual woman in different phases of her menstrual cycle were analysed with a prospective daily rating questionnaire. PMS symptoms were also evaluated in the patients on a daily rating scale.

RESULTS

Of the 32 women, 30 showed significant cyclicity in at least one AIP or PMS symptom (P < 0.05-0.001). Back pain (10/32) was the most frequent AIP pain symptom and sweet craving (10/15) was the most frequent PMS symptom. Pelvic pain (F = 4.823, P = 0.036), irritability (F = 7.399, P = 0.011), cheerfulness (F = 5.563, P = 0.025), sexual desire (F = 8.298, P = 0.007), friendliness (F = 6.157, P = 0.019), breast tenderness (F = 21.888, P = 0.000) and abdominal swelling (F = 16.982, P = 0.000) showed significant cyclicity. Pelvic pain and abdominal swelling (rs = 0.337, P < 0.001) showed the strongest correlation. The age of women with latent AIP was strongly correlated with abdominal swelling during the luteal phase (rs = 0.493, P < 0.01).

CONCLUSION

Our results suggest that the symptoms of AIP patients change during their menstrual cycles.

Effects of progesterone stimulated allopregnanolone on craving and stress response in cocaine dependent men and women

OBJECTIVES

Fluctuations in progesterone levels during the menstrual cycle have been shown to affect physiological and subjective effects of cocaine. Furthermore, our laboratory has demonstrated that following drug-cue exposure, cocaine dependent women with high levels of circulating progesterone display lower diastolic and systolic blood pressure responses and report lower levels of anxiety and drug craving compared to cocaine dependent women with low levels of progesterone. In the current study we examined the role of the progesterone derived neuroactive steroid allopregnanolone (ALLO) on stress arousal, inhibitory control and drug craving in cocaine dependent subjects.

METHODS

Plasma levels of ALLO were measured using GC/MS in 46 treatment-seeking cocaine dependent men and women on day 5 of a 7-day treatment regimen of micronized progesterone (15M/8F) (400mg/day) or placebo (14M/9F) administered in a double blind, randomized manner. As a control, levels of the testosterone derived neurosteroid androstanediol (ADIOL) were also measured. All subjects participated in laboratory sessions on days 5-7 of progesterone/placebo administration in which they were exposed to a series of 5-min personalized guided imagery of either a stressful situation, cocaine use or of a neutral setting and dependent variables including subjective craving, mood, Stroop task as a measure of inhibitory control performance and plasma cortisol were assessed. Participants were grouped by high or low ALLO level and levels of dependent variables compared between ALLO groups.

RESULTS

Progesterone relative to placebo significantly increased ALLO levels with no sex differences. There were no effects of micronized progesterone on the testosterone derived ADIOL. Individuals in the high versus the low ALLO group showed decreased levels of cortisol at baseline, and a higher cortisol response to stress; higher positive mood scores at baseline and improved Stroop performance in the drug-cue and stress conditions, and reduced cocaine craving across all imagery conditions.

CONCLUSIONS

As expected, cocaine dependent individuals administered progesterone showed significantly higher ALLO plasma levels. High levels of ALLO appeared to normalize basal and stress response levels of cortisol, decrease cocaine craving and also contribute to improvements in positive emotion and Stroop performance in response to stress and drug-cue exposures. These findings suggest that the neuroactive steroid ALLO plays a significant role in mediating the positive effects of progesterone on stress arousal, cognitive performance and drug craving in cocaine dependence.

Substance use in women: Current status and future directions

Alcohol and substance use, until recently, were believed to be a predominantly male phenomenon. Only in the last few decades, attention has shifted to female drug use and its repercussions in women. As the numbers of female drug users continue to rise, studies attempt to understand gender-specific etiological factors, phenomenology, course and outcome, and issues related to treatment with the aim to develop more effective treatment programs. Research has primarily focused on alcohol and tobacco in women, and most of the literature is from the Western countries with data from developing countries like India being sparse. This review highlights the issues pertinent to alcohol and substance use in women with a special focus to the situation in India.

Long-term use of methamphetamine disrupts the menstrual cycles and hypothalamic-pituitary-ovarian axis

OBJECTIVES

Long-term use of methamphetamine (MA) induces the neuron damage and leads to multiple neuropsychiatric disorders. However, the effect of MA on the female reproductive functions has not yet been evaluated. The objective of this study was to determine the prevalence of abnormal menstrual cycling in female MA users.

METHODS

Female MA users (N = 113) were recruited from the Zhangjiang Isolated Compulsory Detoxification Center. Gynecologic history and drug use history were recorded, and serum levels of follicle-stimulating hormone, luteinizing hormone, prolactin, estrogen, progesterone, and testosterone were measured.

RESULTS

Long-term use of MA significantly altered the menstrual cycle, and 33.6% women suffered from abnormal uterine bleeding while using MA. Deregulation of sex hormones was observed in 73.3% of participants during abstinence. The most common patterns were simple anovular menstruation, which was caused mainly by a hypothalamic deregulation and pituitary suppression with or without ovarian suppression. Normal hormone levels were observed more frequently in participants abstinent for more than 10 months (39.5%) than in participants who were abstinent for less than 10 months (18.6%). However, no relationship was found between hormone deregulation and age or history of MA use.

CONCLUSIONS

The present data demonstrate that long-term use of MA results in the disruption of menstrual cycles and dysfunction of hypothalamic-pituitary-gonadal axis in women.

Ovarian hormones and drug abuse

There are significant gender differences in course, symptomology, and treatment of substance use disorders. In general data from clinical and preclinical studies of substance use disorders suggest that women are more vulnerable than men to the deleterious consequences of drug use at every phase of the addiction process. In addition data from epidemiologic studies suggest that the gender gap in the prevalence of substance use is narrowing particularly among adolescence. Therefore, understanding the role of estrogen and progesterone in mediating responses to drugs of abuse is of critical importance to women's health. In this review we will discuss findings from clinical and preclinical studies of (1) reproductive cycle phase; (2) endogenous ovarian hormones; and (3) hormone replacement on responses to stimulants, nicotine, alcohol, opioids, and marijuana. In addition, we discuss data from recent studies that have advanced our understanding of the neurobiologic mechanisms that interact with estrogen and progesterone to mediate drug-seeking behavior.

Effects of endogenous and exogenous progesterone on emotional intelligence in cocaine-dependent men and women who also abuse alcohol

OBJECTIVE

As sex differences in substance dependence may impinge upon the perception and regulation of emotion, we assess emotional intelligence (EI) as a function of gender, menstrual cycle (MC) phase and hormonal changes in early abstinent cocaine-dependent individuals who abuse alcohol (CDA).

METHODS

Study 1: The Mayer, Salovey, and Caruso Emotional Intelligence Test (MSCEIT) was administered to 98 CDA (55 M/43 F) and 56 healthy (28 M/28 F) individuals. Performance in women was also assessed by MC phase. Study 2: The MSCEIT was administered to 28 CDA (19 M/9 F) who received exogenous progesterone (400 mg/day) versus placebo for 7 days (study 2).

RESULTS

Study 1: Healthy females were better than healthy males at facilitating thought and managing emotions. This gender discrepancy was not observed in the CDA group. Additionally, all women in the high compared with the low progesterone phase of their MC were better at managing their emotions. Study 2: Exogenous progesterone improved ability to facilitate thought in both males and females.

CONCLUSIONS

CDA women may be vulnerable to difficulties managing and regulating emotions. Gonadal hormones may contribute to this gender effect, as increases in both endogenous and exogenous progesterone improved selective aspects of EI.

Chronic cocaine causes long-term alterations in circadian period and photic entrainment in the mouse

The disruptive effects of cocaine on physiological, behavioral and genetic processes are well established. However, few studies have focused on the actions of cocaine on the adult circadian timekeeping system, and none have explored the circadian implications of long-term (weeks to months) cocaine exposure. The present study was undertaken to explore the actions of such long-term cocaine administration on core circadian parameters in mice, including rhythm period, length of the nocturnal activity period and photic entrainment. For cocaine dosing over extended periods, cocaine was provided in drinking water using continuous and scheduled regimens. The impact of chronic cocaine on circadian regulation was evidenced by disruptions of the period of circadian entrainment and intrinsic free-running circadian period. Specifically, mice under a skeleton photoperiod (1-min pulse of dim light delivered daily) receiving continuous ad libitum cocaine entrained rapidly to the light pulse at activity onset. Conversely, water controls entrained more slowly at activity offset through a process of phase-delays, which resulted in their activity rhythms being entrained 147° out of phase with the cocaine group. This pattern persisted after cocaine withdrawal. Next, mice exposed to scheduled daily cocaine presentations exhibited free-running periods under constant darkness that were significantly longer than water controls and which also persisted after cocaine withdrawal. These cocaine-induced perturbations of clock timing could produce chronic psychological and physiological stress, contributing to increased cocaine use and dependence.

Effects of cocaine on the hypothalamic-pituitary-adrenal axis

INTRODUCTION

Cocaine hydrochloride is a psychoactive substance extracted from the leaves of plants called Erythroxylum coca. Cocaine is the second most commonly used drug in the world after cannabis; 20 % of cocaine users will become long-term cocaine-dependent patients. Different routes of administration may be recognized: smokable modality, intranasal and intravenous. Cocaine is a potent stimulant of the sympathetic nervous system and causes structural changes on the brain, heart, lung, liver and kidney. It has long been known that use of cocaine may produce alterations to the endocrine system. Research on behavioral and neuroendocrine effects of cocaine dates back several years ago and has increasingly focused on alterations of the hypothalamic-pituitary-adrenal (HPA) axis, which appears to be the chief target of cocaine effects.

STUDIES

Animal (mainly rats and monkeys) and human studies have clearly shown a close relation between cocaine consumption and overdrive of the HPA axis. Such activation is likely involved, though via a still undefined mechanism, in the behavioral and cardiovascular changes of drug abusers as well as in the reinforcement/relapse phenomena. Further studies of the pathophysiology of cocaine addicts will help to devise new therapeutic strategies for these patients.

Dose-dependent effectiveness of wheel running to attenuate cocaine-seeking: impact of sex and estrous cycle in rats

RATIONALE

Exercise has shown promise as an intervention for drug addiction; however, little is known regarding the exercise conditions that most effectively reduce relapse vulnerability and whether these conditions differ by sex.

OBJECTIVE

Here, we examined sex differences in the dose-dependent effects of wheel running, an animal model of exercise, during abstinence on subsequent cocaine-seeking.

METHODS

Male and female rats self-administered cocaine (1.5 mg/kg/infusion) under extended access conditions (24 h/day, 4 discrete trials/h) for 10 days. Rats were then given voluntary access to either an unlocked or locked running wheel for 1, 2, 6, or 24 h/day during the 14-day abstinence period. Separate groups of rats were housed in polycarbonate cages during abstinence to control for physical activity that the wheel may provide. Subsequent cocaine-seeking was assessed under a within-session extinction/cue-induced reinstatement procedure. Estrous cycle was monitored in females to determine whether the effectiveness of wheel running varied by estrous cycle phase.

RESULTS

Although females ran more than males, males were more sensitive to the effects of running and showed a dose-dependent decrease in cocaine-seeking with longer access resulting in greater suppression. The dose-effect relationship was less straightforward in females and access to both a locked and unlocked wheel decreased cocaine-seeking with effects dependent on estrous cycle phase. Notably, extended (6 and 24 h/day), but not limited (1 and 2 h/day) access to a wheel surmounted the heightened vulnerability observed in females during estrus.

CONCLUSION

Taken together, our findings suggest that the effectiveness of wheel running is dose-, sex-, and estrous cycle-dependent.

Sex differences in guanfacine effects on drug craving and stress arousal in cocaine-dependent individuals

Currently, no FDA-approved medication exists for the treatment of cocaine use disorder. Furthermore, as women become increasingly more at risk for the consequences of cocaine addiction, the need to establish better-tailored treatment medications is paramount. We examine the effects of the alpha2 adrenergic agonist, guanfacine HCl, on responses to stress and drug cue in a group of cocaine-dependent men and women who also abuse alcohol and nicotine. Forty early abstinent treatment-seeking cocaine-dependent males and females were randomly assigned to receive either daily placebo (12 M/7 F) or guanfacine (2 or 3 mg) (15 M/6 F) for 3 weeks. In week 4, they participated in a laboratory experiment and were exposed to three 10-min guided imagery conditions (stress/stress, cue/cue, and stress/cue), one per day, consecutively in a random, counterbalanced order. Craving, negative emotion, anxiety, and cardiovascular function were assessed at baseline, immediately following imagery exposure, and at various recovery time points. Guanfacine significantly attenuated cocaine craving, alcohol craving, anxiety, and negative emotion following exposure to all three imagery conditions in females, but not males. Guanfacine did, however, reduce sympathetic tone as well as stress and cue-induced nicotine craving and systolic blood pressure (SBP) in both males and females. These findings highlight sex-specific effects of guanfacine on drug craving, anxiety, and negative mood with significant effects in women and not men. The findings suggest further evaluation of guanfacine in the treatment of cocaine use disorder with a specific focus on sex differences in treatment response.

The role of guanfacine as a therapeutic agent to address stress-related pathophysiology in cocaine-dependent individuals

The pathophysiology of cocaine addiction is linked to changes within neural systems and brain regions that are critical mediators of stress system sensitivity and behavioral processes associated with the regulation of adaptive goal-directed behavior. This is characterized by the upregulation of core adrenergic and corticotropin-releasing factor mechanisms that subserve negative affect and anxiety and impinge upon intracellular pathways in the prefrontal cortex underlying cognitive regulation of stress and negative emotional state. Not only are these mechanisms essential to the severity of cocaine withdrawal symptoms, and hence the trajectory of clinical outcome, but also they may be particularly pertinent to the demography of cocaine dependence. The ability of guanfacine to target overlapping stress, reward, and anxiety pathophysiology suggests that it may be a useful agent for attenuating the stress- and cue-induced craving state not only in women but also in men. This is supported by recent research findings from our own laboratory. Additionally, the ability of guanfacine to improve regulatory mechanisms that are key to exerting cognitive and emotional control over drug-seeking behavior also suggests that guanfacine may be an effective medication for reducing craving and relapse vulnerability in many drugs of abuse. As cocaine-dependent individuals are typically polydrug abusers and women may be at a greater disadvantage for compulsive drug use than men, it is plausible that medications that target catecholaminergic frontostriatal inhibitory circuits and simultaneously reduce stress system arousal may provide added benefits for attenuating cocaine dependence.

The effects of exogenous progesterone on drug craving and stress arousal in cocaine dependence: impact of gender and cue type

AIMS

Exogenous progesterone has been shown to attenuate the rewarding effects of cocaine. However, its effects on provoked drug craving, stress arousal and cognitive performance has not been systematically investigated in cocaine dependent men and women. Thus, we conducted a double-blind placebo-controlled study assessing the efficacy of progesterone in reducing provoked drug craving, stress system arousal and improving cognitive performance in cocaine dependent men and women.

METHODS

Forty-two early abstinent treatment-seeking cocaine dependent individuals were randomly assigned to either daily doses of placebo (12M/9F) or micronized progesterone (12M/9F) (400 mg/day), for 7 days. Under experimental conditions, all subjects were exposed to three 5-min personalized guided imagery conditions (stress, cocaine cue, relaxing), one per day, consecutively in a random, counterbalanced order. Subjective craving, mood, hypothalamic-pituitary-adrenal (HPA) and cardiovascular output, and a cognitive measure of inhibitory control (Stroop Color Word Task) were assessed pre- and post imagery.

RESULTS

Progesterone relative to placebo significantly decreased cue-induced craving and cortisol responses and increased cue-induced ACTH. In addition, women but not men receiving progesterone reported lower ratings of negative emotion and higher ratings of relaxed mood following stress exposure. Improved Stroop performance was observed in all participants receiving progesterone, across all conditions.

CONCLUSIONS

Progesterone was selectively effective in reducing cocaine cue-induced but not stress-related cocaine craving as well as specific measures of the provoked arousal state. Findings suggest that progesterone's effects on drug craving and arousal are moderated by both the type of environmental cue exposure and gender.

The role of ovarian steroid hormones in mood

Fluctuations in ovarian hormones across the menstrual cycle have long been considered a determinant of mood in women. The majority of studies, however, use menstrual cycle phase as proxy for hormone levels. We measured ovarian hormone levels directly in order to examine the relationship between daily hormone levels and mood in non-help-seeking women. Participants (n=19) provided daily information about their positive and negative moods, and collected their first morning-voided urine for 42days, which was analyzed for estrogen and progesterone metabolites (E1G and PdG). The independent contributions of daily E1G, PdG, stress, physical health, and weekly social support, were calculated for 12 daily mood items, and composite measures of positive and negative mood items, using linear mixed models. E1G or PdG contributed to few mood items: E1G measured 2days prior contributed negatively to the model for Motivation, while E1G measured 3days prior contributed negatively to Getting Along with Others, and E1G measured 4days prior contributed negatively to Anxiety. PdG, measured the same day and 1day prior, contributed positively to the models of Irritability, and PdG measured 5days prior contributed positively to Difficulty Coping. By contrast, the variables stress and physical health contributed significantly to all the mood items, as well as both composite positive and negative mood measures. These findings demonstrate that, compared to stress and physical health, ovarian hormones make only a small contribution to daily mood. Thus, fluctuations in ovarian hormones do not contribute significantly to daily mood in healthy women.

Neural correlates of stress-induced and cue-induced drug craving: influences of sex and cocaine dependence

OBJECTIVE

Although stress and drug cue exposure each increase drug craving and contribute to relapse in cocaine dependence, no previous research has directly examined the neural correlates of stress-induced and drug cue-induced craving in cocaine-dependent women and men relative to comparison subjects.

METHOD

Functional MRI was used to assess responses to individualized scripts for stress, drug/alcohol cue and neutral-relaxing-imagery conditions in 30 abstinent cocaine-dependent individuals (16 women, 14 men) and 36 healthy recreational-drinking comparison subjects (18 women, 18 men).

RESULTS

Significant three-way interactions between diagnostic group, sex, and script condition were observed in multiple brain regions including the striatum, insula, and anterior and posterior cingulate. Within women, group-by-condition interactions were observed involving these regions and were attributable to relatively increased regional activations in cocaine-dependent women during the stress and, to a lesser extent, neutral-relaxing conditions. Within men, group main effects were observed involving these same regions, with cocaine-dependent men demonstrating relatively increased activation across conditions, with the main contributions from the drug and neutral-relaxing conditions. In men and women, subjective drug-induced craving measures correlated positively with corticostriatal-limbic activations.

CONCLUSIONS

In cocaine dependence, corticostriatal-limbic hyperactivity appears to be linked to stress cues in women, drug cues in men, and neutral-relaxing conditions in both. These findings suggest that sex should be taken into account in the selection of therapies in the treatment of addiction, particularly those targeting stress reduction.

Cocaine modulates pathways for photic and nonphotic entrainment of the mammalian SCN circadian clock

Cocaine abuse is highly disruptive to circadian physiological and behavioral rhythms. The present study was undertaken to determine whether such effects are manifest through actions on critical photic and nonphotic regulatory pathways in the master circadian clock of the mouse suprachiasmatic nucleus (SCN). Impairment of SCN photic signaling by systemic (intraperitoneal) cocaine injection was evidenced by strong (60%) attenuation of light-induced phase-delay shifts of circadian locomotor activity during the early night. A nonphotic action of cocaine was apparent from its induction of 1-h circadian phase-advance shifts at midday. The serotonin receptor antagonist, metergoline, blocked shifting by 80%, implicating a serotonergic mechanism. Reverse microdialysis perfusion of the SCN with cocaine at midday induced 3.7 h phase-advance shifts. Control perfusions with lidocaine and artificial cerebrospinal fluid had little shifting effect. In complementary in vitro experiments, photic-like phase-delay shifts of the SCN circadian neuronal activity rhythm induced by glutamate application to the SCN were completely blocked by cocaine. Cocaine treatment of SCN slices alone at subjective midday, but not the subjective night, induced 3-h phase-advance shifts. Lidocaine had no shifting effect. Cocaine-induced phase shifts were completely blocked by metergoline, but not by the dopamine receptor antagonist, fluphenazine. Finally, pretreatment of SCN slices for 2 h with a low concentration of serotonin agonist (to block subsequent serotonergic phase resetting) abolished cocaine-induced phase shifts at subjective midday. These results reveal multiple effects of cocaine on adult circadian clock regulation that are registered within the SCN and involve enhanced serotonergic transmission.

New findings on biological factors predicting addiction relapse vulnerability

Relapse is a highly prevalent phenomenon in addiction. This paper examines the new research on identifying biological factors that contribute to addiction relapse risk. Prospective studies examining relapse risk are reviewed, and clinical, biological, and neural factors that predict relapse risk are identified. Clinical factors, patient-related factors, and subjective and behavioral measures such as depressive symptoms, stress, and drug craving all predict future relapse risk. Among biological measures, endocrine measures such as cortisol and cortisol/corticotropin (ACTH) ratio as a measure of adrenal sensitivity and serum brain-derived neurotrophic factor were also predictive of future relapse risk. Among neural measures, brain atrophy in the medial frontal regions and hyperreactivity of the anterior cingulate during withdrawal were identified as important in drug withdrawal and relapse risk. Caveats pertaining to specific drug abuse type and phase of addiction are discussed. Finally, significant implications of these findings for clinical practice are presented, with a specific focus on determining biological markers of relapse risk that may be used to identify those individuals who are most at risk of relapse in the clinic. Such markers may then be used to assess treatment response and develop specific treatments that will normalize these neural and biological sequelae so as to significantly improve relapse outcomes.

Individual vulnerability to addiction

The process of addiction is often studied in the neurosciences as a function of the quantity or type of substance consumed, with the ultimate goal of counteracting these effects by other pharmacological means. However, epidemiology and clinical research have extensively demonstrated that most individuals who use drugs do not develop dependence. Numerous factors may explain an individual's propensity to addiction. This review discusses these paradigms and summarizes research on individual differences that encompass cultural and sociodemographic factors, psychiatric or psychological vulnerability, and biological or genetic propensity to addiction. Although these different factors often interact in the expression of vulnerable phenotypes, it is possible to alter or control specific sources of vulnerability. For these reasons, integrating individual vulnerability to addiction across different research disciplines is likely to provide the greatest advances for intervention and prevention efforts.

Substance abuse in women

Gender differences in substance use disorders (SUDs) and treatment outcomes for women with SUDs have been a focus of research in the last 15 years. This article reviews gender differences in the epidemiology of SUDs, highlighting the convergence of male/female prevalence ratios of SUDs in the last 20 years. The telescoping course of SUDs, recent research on the role of neuroactive gonadal steroid hormones in craving and relapse, and sex differences in stress reactivity and relapse to substance abuse are described. The role of co-occurring mood and anxiety, eating, and posttraumatic stress disorders is considered in the epidemiology, natural history, and treatment of women with SUDs. Women's use of alcohol, stimulants, opioids, cannabis, and nicotine are examined in terms of recent epidemiology, biologic and psychosocial effects, and treatment. Although women may be less likely to enter substance abuse treatment than men over the course of the lifetime, once they enter treatment, gender itself is not a predictor of treatment retention, completion, or outcome. Research on gender-specific treatments for women with SUDs and behavioral couples treatment has yielded promising results for substance abuse treatment outcomes in women.

Elevated cortisol and learning and memory deficits in cocaine dependent individuals: relationship to relapse outcomes

OBJECTIVE

Cocaine dependence is characterized by stress system dysregulation, including elevated cortisol activity, emotional negativity, and behavioral disinhibition. High levels of stress and glucocorticoids are also known to affect learning, memory and executive function. Therefore, we examined the relationships between chronic cocaine use, elevated distress and learning and memory dysfunction in abstinent cocaine dependent (CD) individuals, and whether these measures were associated with cocaine relapse outcomes.

METHOD

Stress was assessed in 36 inpatient treatment engaged CD individuals and 36 demographically matched healthy control (HC) participants using the Perceived Stress Scale (PSS) and repeated morning salivary cortisol levels over three consecutive days. The Rey Auditory Verbal Learning Test (RAVLT) was conducted to measure verbal learning, memory, and executive function. Prospective assessment of cocaine use outcomes during 90 days following discharge from inpatient treatment was also conducted.

RESULTS

CD patients showed higher levels of distress compared to controls in PSS scores and cortisol levels. They also demonstrated a significantly reduced learning curve, and fewer correct responses and more errors on recognition. Elevated cortisol was significantly associated with worse RAVLT performance in CD patients. Poor memory scores, but not distress measures, were significantly associated with greater cocaine use after inpatient treatment.

CONCLUSIONS

These findings are the first to demonstrate that learning and memory deficits in CD individuals are associated with enhanced cortisol and with cocaine use outcomes after inpatient treatment. The findings are consistent with recent addiction models suggesting that chronic cocaine-related neuroadaptations affects learning and memory function, which in turn, influences drug use outcomes.

Time-of-day differences in dopamine clearance in the rat medial prefrontal cortex and nucleus accumbens

Circadian rhythms influence cocaine-seeking behavior in rats, and this behavior may be mediated by variability in the rate of extracellular dopamine clearance across the day:night cycle. We used rotating disk electrode voltammetry to examine dopamine clearance and inhibition of clearance by cocaine in the rat medial prefrontal cortex (mPFC) and nucleus accumbens (NAc). Rats were housed under light:dark conditions (LD, 12 h:12 h) or in constant darkness (DD), the latter given just prior to the day of sacrifice. Tissue was collected at 4-h intervals under LD and DD conditions. Under LD, dopamine clearance in both brain regions was greatest at 4h after lights on. Under DD, there was a blunted but still rhythmic pattern of dopamine clearance across the 24-h cycle. Cocaine-induced inhibition of dopamine clearance in the mPFC was not different across the day:night cycle in rats under LD. Paradoxically, under DD, dopamine clearance in the mPFC was enhanced by cocaine at ZT16, 4 h into the subjective night, and only minimally inhibited at other times. In the NAc, cocaine inhibition of dopamine clearance was lowest at ZT4 under LD, and did not vary under DD. We conclude that dopamine clearance varies both in a diurnal and possibly in a circadian manner in the mPFC, and in a diurnal manner in the NAc. These results indicate that light itself may be used to manipulate molecules implicated in drug addiction.

Sex differences in sleep and sleep-dependent learning in abstinent cocaine users

Sleep and sleep-dependent learning are impaired in male cocaine users during abstinence, but for female users little is known. Cocaine dependent men (n=12) and women (n=14), and control participants (n=19) participated in this study of sleep and sleep-dependent learning. Cocaine users were assessed at 3, 10 and 20 days of abstinence and controls were studied over one night. Total sleep time, sleep efficiency and overnight motor learning were the main outcome measures. Cocaine dependent men compared to women exhibited deteriorations in sleep time, sleep efficiency, and overnight learning as abstinence progressed from 3 to 20 days. At abstinence day 3, cocaine dependent men and women were no different than control participants in the main outcomes. However, there were significant differences between cocaine men at abstinence day 20 and controls in sleep time and sleep-dependent learning, but no differences between controls and cocaine dependent women. There is growing evidence that sleep disturbances are associated with cocaine abuse and abstinence and have functional consequences that may be relevant to the development of effective treatments. The absence of sleep disturbances in women suggests a need to understand the mechanisms underlying these differences, as such knowledge could lead to novel therapies in cocaine dependence.

Sex differences in drug-related stress-system changes: implications for treatment in substance-abusing women

Extensive research indicates that chronic substance abuse disrupts stress and reward systems of the brain. Gender variation within these stress-system alterations, including the impact of sex hormones on these changes, may influence sex-specific differences in both the development of, and recovery from, dependency. As such, gender variations in stress-system function may also provide a viable explanation for why women are markedly more vulnerable than men to the negative consequences of drug use. This article therefore initially reviews studies that have examined gender differences in emotional and biophysiological changes to the stress and reward system following the acute administration of drugs, including cocaine, alcohol, and nicotine. The article then reviews studies that have examined gender differences in response to various types of stress in both healthy and drug-abusing populations. Studies examining the impact of sex hormones on these gender-related responses are also reported. The implications of these sex-specific variations in stress and reward system function are discussed in terms of both comorbid psychopathology and treatment outcome.