Does effective management of sleep disorders reduce substance dependence?

A qualitative assessment of insomnia in recovering alcohol-dependent patients

Insomnia is a common symptom that may interfere with the efforts of alcohol-dependent patients to initiate and maintain sobriety. This study investigates the experiences of recovering alcohol-dependent patients with insomnia as well as preferences for treatment strategies. Semi-structured interviews were conducted with 27 patients in Ukraine and Germany. Most of the patients experienced negative psychological (n = 21), physiological (n = 14) effects and negative daytime consequences during insomnia. All 27 patients were engaged in nonpharmacological approaches to insomnia and 52% used pharmacological approaches to manage insomnia. This study provides insight for understanding how alcohol-dependent patients in recovery perceive insomnia.

Sleep restriction during opioid abstinence affects the hypothalamic-pituitary-adrenal (HPA) axis in male and female rats

Hypothalamic-pituitary-adrenal (HPA) axis dynamics are disrupted by opioids and may be involved in substance abuse; this persists during withdrawal and abstinence and is associated with co-morbid sleep disruption leading to vulnerability to relapse. We hypothesized that chronic sleep restriction (SR) alters the HPA axis diurnal rhythm and the sexually dimorphic response to acute stressor during opioid abstinence. We developed a rat model to evaluate the effect of persistent sleep loss during opioid abstinence on HPA axis dynamics in male and female rats. Plasma ACTH and corticosterone were measured diurnally and in response to acute restraint stress in rats Before (control) compared to During subsequent opioid abstinence without or with SR. Abstinence, regardless of sleep state, led to an increase in plasma ACTH and corticosterone in the morning in males. There was a tendency for higher PM plasma ACTH during abstinence in SR males (p = 0.076). ACTH and corticosterone responses to restraint were reduced in male SR rats whereas there was a failure to achieve the post-restraint nadir in female SR rats. There was no effect of the treatments or interventions on adrenal weight normalized to body weight. SR resulted in a dramatic increase in hypothalamic PVN AVP mRNA and plasma copeptin in male but not female rats. This corresponded to the attenuation of the HPA axis stress response in SR males during opioid abstinence. We have identified a potentially unique, sexually dimorphic role for magnocellular vasopressin in the control of the HPA axis during opioid abstinence and sleep restriction.

Sleep, psychiatric and socioeconomic factors associated with substance use in a large population sample: A cross-sectional study

Multiple elements modulate drug use, including sleep, which is increasingly being considered as an important contributor to substance use and abuse. The present study aimed to evaluate the association between sleep, psychiatric and socioeconomic/demographic factors and substance use in a large-scale representative sample from the city of São Paulo, Brazil. Data from the 2007 São Paulo Epidemiological Sleep Study (EPISONO) database were used. In the EPISONO study, volunteers underwent a polysomnographic exam and completed a series of questionnaires to assess objective and subjective sleep quality and associated comorbidities. Drug use was assessed using the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST). Linear (univariate and multivariate) and logistic regressions were performed to identify factors associated with the use of the 4 most commonly used substances in the sample (tobacco, alcohol, cannabis and cocaine/crack). Structural equation models were used to establish theoretical networks to explain the relationship between sleep, psychiatric and socioeconomic factors and use of these substances. The logistic regression results showed that psychiatric symptoms, lower income, and poorer subjective sleep were the main factors associated with tobacco consumption; gender and occupational status with alcohol intake; age and occupation with cannabis use; and education with cocaine/crack use. The structural equation models partially supported these findings and identified significant effects of psychiatric symptoms on tobacco consumption, both directly and mediated by sleep. Our results reinforce previous findings concerning factors associated with generally misused substances and suggest that sleep should be considered as an important element in future substance use disorder studies.

Intermittent REM sleep deprivation attenuates the development of morphine tolerance and dependence in male rats

Opioid agonists are used in clinic for pain management, however this application is challenged by development of tolerance and dependence following prolonged exposure. Various approaches have been suggested to address this concern, however, there is still no consensus among the researchers. Neural processing of sleep and nociception are co-regulated through shared brain regions having bidirectional interplays. Thus, we aimed to investigate whether application of REM sleep deprivation (REM-SD) could affect morphine analgesic tolerance and dependence. To this end, adult male rats underwent sleep deprivation during light and dark phases (LSD and DSD, respectively) using the inverted flower pot method and then tolerance and dependence was induced by repeated injection of morphine for 7 days (10 mg/kg, daily, i.p.). Results indicated that REM-SD delays the development of tolerance to morphine during both phases; however this effect was more potent following LSD. Moreover, LSD decreased the baseline thermal threshold and total withdrawal score. One possible hypothesis for our observations is REM-SD-induced attenuation of orexin system which is still controversial among the researchers. Other stronger possibilities might be down-regulation of opioid receptors in response to sleep loss experience. Finally, it seems that modification of sleep periods may assist to decrease the severity of opioid tolerance and dependence.

Geographically based risk assessment of sleep disorders and disease states impacting medical readiness across active duty army installations from military medical databases in fiscal year 2017

BACKGROUND

The impact of sleep disorders on active duty Soldiers' medical readiness is clinically significant. Sleep disorders often present high comorbidity with disease states impacting readiness ranging from obesity and drug dependence. Patient data generated from military health databases can be accessed to examine such relationships. The current study performed a risk assessment of sleep disorders, obesity, tobacco use, and substance abuse based on geographical distribution of active duty Army installations through a comprehensive analysis of the Office of the Army Surgeon General Health of the Force report, specifically for Fiscal Year 2017, which summarizes data collected during 2016.

METHODS

Health incidences (percent active duty per installation) were queried from the Health of the Force Fiscal Year 2017 (n = 471,000; 85.5% male, >70% between 18 and 34). Nonparametric ranked tests identified active duty Army installations at low risk (green; <25% percentile relative to mean rank), moderate risk (amber; 25%-50% percentile relative to mean rank), and high risk (red; >75% percentile relative to mean rank). Pearson's correlations determined extent of generalized comorbidity of sleep disorders with obesity, tobacco use, and substance abuse across all installations.

RESULTS

Large combat arms and training installations of the Southern U.S. were at highest risk for sleep disorder. Mean rank comparisons for sleep disorders versus obesity (P = .306), tobacco use (P = .378), and substance abuse (P = .591) did not differ for each installation. There was a high degree of generalized comorbidity of diagnosed sleep disorder with obesity (P < .001; r² = 0.963), tobacco use (P < .001; r² = 0.928), and substance abuse (P < .001; r² = 0.968).

CONCLUSIONS

These risk assessments mirror geographical risk data from civilian populations which is surprising because there is a large degree of inter-individual variability in geographical origin, race/ethnicity, and socioeconomic statuses within a single Army installation. Nevertheless, these data demonstrate strong geographical influences on medical readiness in active duty Soldiers comparable to civilian sectors.

Alterations in circadian rhythms following alcohol use: A systematic review

Increasing evidence suggest a bidirectional link between disrupted circadian rhythms and alcohol use disorders (AUD). A better understanding of these alcohol-induced changes in circadian rhythms will likely provide important therapeutic solutions. We conducted a systematic review based on the PubMed database examining biological rhythms in all stages of alcohol use: acute alcohol consumption, AUD, alcohol withdrawal, and abstinence. Different changes in circadian rhythms have been observed after a single acute alcohol intake, but also during AUD and alcohol withdrawal. Following a single acute alcohol intake, changes in biological rhythms are dose-dependent, reflected in the melatonin and cortisol secretions, and the core body temperature (CBT) rhythms. These alterations normalize the next morning and appear mostly for acute alcohol intake higher than 0.5 g/kg. These alterations are more severe during AUD and persist over time. In addition, interestingly, opposite patterns of the melatonin physiological ratio between diurnal and nocturnal secretion (N/D ratio < 1) have been observed during AUD and appear to be a marker of chronic daily use. During alcohol withdrawal, circadian rhythms desynchronization correlates with the severity of alcohol withdrawal symptoms and withdrawal complications such as delirium tremens. During abstinence a resynchronization of circadian rhythms of cortisol and CBT appears in most patients about 1 month after alcohol withdrawal. Disruption of melatonin circadian rhythms can persist after 3-12 weeks of abstinence. The circadian genetic vulnerability associated with biological rhythms alterations in alcohol use disorders increases the risk of relapses. Circadian-based interventions could play a critical role in preventing and treating AUD.

Insomnia Symptoms in Patients With Substance Use Disorders During Detoxification and Associated Clinical Features

Background: Insomnia is highly prevalent in patients with substance use disorders (SUD), and it has been related to a worse course of addiction. Insomnia during detoxification in a hospital has not been adequately studied. This study aims to compare sociodemographic, clinical, and psychopathological characteristics of SUD patients undergoing a detoxification program, by comorbidity and insomnia symptoms. Methodology: We recruited 481 patients who received pharmacological and psychotherapeutic treatment for detoxification. They were evaluated through semi-structured interviews, standardized questionnaires, and a specific sleep log. A bivariate and multivariate analysis of the data was performed. Results: Insomnia was reported by 66.5% patients, with sleep-maintenance insomnia the most frequent issue, followed by early morning awakening and sleep-onset insomnia. Patients with alcohol use disorder and cannabis use disorder had higher prevalence of sleep-onset insomnia. Patients with cocaine and heroin use disorder had higher prevalence of sleep-maintenance insomnia. Independent factors that allowed the identification of insomnia symptoms included being female (OR: 3.43), polysubstance use (OR: 2.85), comorbid anxiety disorder (OR: 2.02), and prior admission for detoxification (OR: 1.22). Conclusions: Insomnia symptoms are very prevalent in patients admitted for detoxification. The diagnosis and therapeutic strategies for the insomnia symptoms should be improved, especially in women and in patients with greater addiction severity and with anxiety disorders.

Factors Associated with Sleep Disorders among Methadone-Maintained Drug Users in Vietnam

Sleep quality among heroin-dependent patients receiving methadone maintenance treatment (MMT) is not fully investigated in Vietnam. This study explored the prevalence of poor sleep quality in methadone-maintained patients and associated factors. This cross-sectional included 395 MMT patients at three clinics in Nam Dinh province, Vietnam. The Pittsburgh Sleep Quality Index (PSQI) was employed to measure patients’ sleep quality. Sociodemographic, clinical, behavioral, psychological, and social support characteristics were collected. Multivariate Logistic and Generalized Linear Regression models were applied to identify associated factors. Among 395 patients, 26.6% had poor sleep quality according to the PSQI scale. People having jobs were less likely to have poor sleep quality and lower PSQI scores compared to unemployed patients. Those having spouses had lower PSQI scores than single patients. High depression, anxiety, and stress scores were associated with poor sleep quality and high PSQI scores. A longer duration of MMT increased the likelihood of experiencing poor sleep quality. Patients smoking tobacco daily or concurrently using drugs had lower PSQI scores than those that did not. This study highlights a moderate prevalence of poor sleep quality among Vietnamese MMT patients. Regular evaluation, appropriate psychological management, and social support, as well as the provision of employment opportunities, potentially improve the sleep quality of methadone-maintained patients.

Use of alcohol as a sleep aid, unhealthy drinking behaviors, and sleeping pill use among women veterans

OBJECTIVES

Sleep complaints, such as insomnia and sleep disturbances caused by posttraumatic stress disorder (PTSD), are more common among women veterans than nonveteran women. Alcohol use among some women may be partially motivated by the desire to improve sleep. This study evaluated rates of alcohol use as a sleep aid among women veterans and explored the relationship between alcohol use to aid sleep and drinking frequency and sleeping pill use.

DESIGN AND SETTING

National cross-sectional population-based residential mail survey on sleep and other symptoms.

PARTICIPANTS

Random sample of women veteran VA users who completed a postal survey (N = 1533).

INTERVENTIONS

None.

MEASUREMENTS

The survey included demographics, Insomnia Severity Index, Primary Care PTSD screen, and items on alcohol use frequency (days/week), use of prescription or over-the-counter sleep medications, and use of alcohol as a sleep aid (yes/no for each item) over the past month.

RESULTS

A total of 14.3% of respondents endorsed using alcohol to aid sleep. Logistic regression models showed more severe insomnia (odds ratio [OR] = 1.03; 95% confidence interval [CI]: 1.01-1.06) and PTSD (OR = 2.11; 95% CI: 1.49-2.97) were associated with increased odds of using alcohol to aid sleep. Alcohol use to aid sleep was associated with increased odds of daily drinking (OR = 8.46; 95% CI: 4.00-17.87) and prescription (OR = 1.79; 95% CI: 1.34-2.38) and over-the-counter sleep aid use (OR = 1.54; 95% CI: 1.12-2.11).

CONCLUSIONS

Insomnia and PTSD may increase risk for using alcohol as a sleep aid, which may increase risk for unhealthy drinking and for mixing alcohol with sleep medications. Findings highlight the need for alcohol use screening in the context of insomnia and for delivery of cognitive-behavioral therapy for insomnia to women veterans with insomnia.

Several clock genes polymorphisms are meaningful risk factors in the development and severity of cannabis addiction

Circadian rhythms have been related to psychiatric diseases and regulation of dopaminergic transmission, especially in substance abusers. The relationship between them remained enigmatic and no data on the role of clock genes on cannabis dependence have been documented. We aimed at exploring the role of clock gene genotypes as potential predisposing factor to cannabis addiction, using a high throughput mass spectrometry methodology that enables the large-scale analysis of the known relevant polymorphisms of the clock genes. We have conducted a case-control study on 177 Caucasians categorizing between cannabis-addicted subjects and casual consumers based on structured interviews recorded socio-demographic data, AUDIT, Fagerström test, MINI, and medical examinations. Alcohol, opiates, and stimulants' consumption was as exclusion criteria. We report an association between several Single Nucleotide Polymorphism (SNP)s in main circadian genes SNPs, especially the gene locus HES7/PER1 on chromosome 17 and cannabis consumption as well as the development of neuropsychiatric and social disorders. This SNP's signature that may represent a meaningful risk factor in the development of cannabis dependence and its severity requires to be deeply explored in a prospective study.

Substance use, sleep and intervention design: insights from qualitative data

Background: Alcohol and other drug use is associated with poor sleep quality and quantity, but there is limited qualitative research exploring substance users' experiences of sleep and few psychosocial sleep interventions for them. Aim: To inform the development of psychosocial interventions to improve sleep amongst people reporting drug/alcohol problems. Method: Qualitative data were collected during a sleep survey. Of the 549 drug/alcohol users completing the survey, 188 (34%) provided additional information about their sleep using a free text box. Responses were analysed via Iterative Categorisation. Findings were reviewed with reference to the Behaviour Change Wheel (BCW). Results: All data were categorised inductively under five headings: (i) sleep quality; (ii) nature of sleep problems; (iii) sleep and substances; (iv) factors improving sleep quality; (v) factors undermining sleep quality. Substance use undermined sleep, but poor sleep often persisted after substance use had ceased. Sleep problems were diverse; as were the causes of, and strategies for dealing with, those problems. Causes and strategies had biological, psychological, social and environmental roots. Conclusions: The BCW facilitated the identification of intervention components that might improve the sleep of people who use substances. These components relate to education, training, enablement, modelling, service provision, guidelines and environment.

Sleep in lonely heroin-dependent patients receiving methadone maintenance treatment: longer sleep latency, shorter sleep duration, lower sleep efficiency, and poorer sleep quality

Given the socially isolated status of Chinese heroin-dependent patients (HDPs) and the significant association between loneliness and sleep problem in the general population, the impact of loneliness on sleep of HDPs is potentially substantial. The study aimed to test whether loneliness is associated with poor sleep in terms of quantity and quality in a consecutive sample of Chinese HDPs receiving methadone maintenance treatment (MMT). The study participants were 603 HDPs of three MMT clinics in Wuhan, China. Data on socio-demographic and clinical characteristics were collected by a standardized self-administered questionnaire. Sleep outcomes included sleep latency, sleep duration, sleep efficiency, and sleep quality. We measured depressive symptoms, loneliness, and sleep quality by using Zung’s Self-rating Depression Scale, the single-item self-report of loneliness, and the Pittsburgh Sleep Quality Index, respectively. Multiple linear regression was used to examine whether loneliness is independently associated with sleep measures. After controlling for the confounding effects of potential socio-demographic and clinical variables, loneliness was significantly associated with longer sleep latency, shorter sleep duration, lower sleep efficiency, and poorer sleep quality. Loneliness may exacerbate sleep disturbance in Chinese HDPs of MMT clinics. Psychosocial interventions aimed at reducing loneliness in MMT clinics would improve the sleep of HDPs.

Disturbing sleep and sleepfulness during recovery from substance dependence in residential rehabilitation settings

There is evidence that poor sleep mitigates recovery from substance dependence and increases risk of relapse. However, to date research literature is located within biomedical, clinical and psychological paradigms. To complement the extant work, this article offers a sociological exploration of sleep in the context of recovery from dependence on alcohol and/or other drugs. Drawing on qualitative data generated through interviews with 28 men and women living in residential rehabilitation settings in England, we provide a detailed exploration of sleep practices focusing on how these are enacted throughout the night. We offer the concept of 'sleepfulness' to suggest that sleep should not be understood simply as being other than awake; rather it involves a myriad of associations between diverse actants - human and non-human - that come to 'fill up', enable and assemble sleep. Together these empirical insights and conceptualisations disturb the ontology of sleep and point to the fulsome dimensions of the category.

Altered activity-based sleep measures in rhesus monkeys following cocaine self-administration and abstinence

BACKGROUND

Impairments in sleep and cognitive function have been observed in patients with substance abuse disorders and may be potential factors contributing to drug relapse. In addition, sleep disruption may itself contribute to cognitive deficits. In the present study we examined the impact of prolonged cocaine self-administration and abstinence on actigraphy-based measures of night-time activity in rhesus macaques as an inferential measure of sleep, and determined whether sleep-efficiency correlated with cognitive impairments in the same subjects on drug free days.

METHODS

Actigraphy data was obtained from a group of rhesus macaques intravenously self-administering cocaine (n=6) and a control group (n=5). Periods were evaluated during which the mean cumulative doses of cocaine were 3.0+0.0 and 4.5+0.2mg/kg/day for 4days (Tuesday-Thursday) each week.

RESULTS

Actigraphy-based sleep efficiency decreased during days of cocaine self-administration in a dose-dependent manner. Consistent with this observation, sleep became more fragmented. Activity-based sleep efficiency normalized during the weekend without cocaine prior to cognitive assessment on Monday. The magnitude of activity-based sleep disruption during self-administration did not correlate with the level of cognitive impairment on drug free days. With continued self-administration, the impact of cocaine on activity-based sleep efficiency declined indicating the development of tolerance.

CONCLUSIONS

Cocaine self-administration disrupted sleep efficiency in rhesus macaques as measured by actigraphy, but normalized quickly in the absence of cocaine. The cognitive impairment observed on drug free days was unlikely to be related to disruption of the nightly activity patterns on days of cocaine self-administration.

The Effects of Lithium Carbonate Supplemented with Nitrazepam on Sleep Disturbance during Cannabis Abstinence

STUDY OBJECTIVE

Sleep disturbance is a hallmark feature of cannabis withdrawal. In this study we explored the effects of lithium treatment supplemented with nitrazepam on objective and subjective measures of sleep quality during inpatient cannabis withdrawal.

METHODS

Treatment-seeking cannabis-dependent adults (n = 38) were admitted for 8 days to an inpatient withdrawal unit and randomized to either oral lithium (500 mg) or placebo, twice daily in a double-blind RCT. Restricted nitrazepam (10 mg) was available on demand (in response to poor sleep) on any 3 of the 7 nights. Dependent outcome measures for analysis included repeated daily objective actigraphy and subjective sleep measures throughout the 8 day detox, subjective cannabis withdrawal ratings, and detoxification completion rates.

RESULTS

Based on actigraphy, lithium resulted in less fragmented sleep compared to placebo (p = 0.04), but no other objective measures were improved by lithium. Of the subjective measures, only nightmares were suppressed by lithium (p = 0.04). Lithium did not have a significant impact on the use of nitrazepam. Sleep bout length (p < 0.0001), sleep efficiency (p < 0.0001), and sleep fragmentation (p = 0.05) were improved on nights in which nitrazepam was used. In contrast, only night sweats improved with nitrazepam from the subjective measures (p = 0.04). A Cox regression with daily repeated measures of sleep efficiency averaged across all people in the study a predictor suggests that a one-unit increase in sleep efficiency (the ratio of total sleep time to the total time in bed expressed as a percentage) resulted in a 14.6% increase in retention in treatment (p = 0.008, Exp(B) = 0.854, 95% CI = 0.759-0.960). None of the other sleep measures, nor use of lithium or nitrazepam were significantly associated with retention in treatment.

CONCLUSIONS

Lithium seems to have only limited efficacy on sleep disturbance in cannabis withdrawal. However the nitrazepam improved several actigraphy measures of sleep disturbance, warranting further investigation. Discord between objective and subjective sleep indices suggest caution in evaluating treatment interventions with self-report sleep data only.

Assessment and treatment of insomnia in adult patients with alcohol use disorders

Insomnia in patients with alcohol dependence has increasingly become a target of treatment due to its prevalence, persistence, and associations with relapse and suicidal thoughts, as well as randomized controlled studies demonstrating efficacy with behavior therapies and non-addictive medications. This article focuses on assessing and treating insomnia that persists despite 4 or more weeks of sobriety in alcohol-dependent adults. Selecting among the various options for treatment follows a comprehensive assessment of insomnia and its multifactorial causes. In addition to chronic, heavy alcohol consumption and its effects on sleep regulatory systems, contributing factors include premorbid insomnia; co-occurring medical, psychiatric, and other sleep disorders; use of other substances and medications; stress; environmental factors; and inadequate sleep hygiene. The assessment makes use of history, rating scales, and sleep diaries as well as physical, mental status, and laboratory examinations to rule out these factors. Polysomnography is indicated when another sleep disorder is suspected, such as sleep apnea or periodic limb movement disorder, or when insomnia is resistant to treatment. Sobriety remains a necessary, first-line treatment for insomnia, and most patients will have some improvement. If insomnia-specific treatment is needed, then brief behavioral therapies are the treatment of choice, because they have shown long-lasting benefit without worsening of drinking outcomes. Medications work faster, but they generally work only as long as they are taken. Melatonin agonists; sedating antidepressants, anticonvulsants, and antipsychotics; and benzodiazepine receptor agonists each have their benefits and risks, which must be weighed and monitored to optimize outcomes. Some relapse prevention medications may also have sleep-promoting activity. Although it is assumed that treatment for insomnia will help prevent relapse, this has not been firmly established. Therefore, insomnia and alcohol dependence might be best thought of as co-occurring disorders, each of which requires its own treatment.

Are you Sleeping? Pilot Comparison of Self-Reported and Objective Measures of Sleep Quality and Duration in an Inpatient Alcoholism Treatment Program

Sleep disturbances are common among alcohol-dependent individuals and can increase risk of relapse. The current study compares subjective and objective measures of sleep quality and duration and describes the prevalence of baseline sleep disturbances in an inpatient population of alcoholics undergoing their first week of detoxification. At baseline, the PSQI revealed that 79% of participants were above the cutoff score (≥5) for clinically meaningful sleep disturbances (mean = 12.57, SD = 4.38). Actigraphy results revealed that average sleep efficiency was 75.89%. Sleep efficiency scores were significantly correlated with self-reported sleep efficiency (P = 0.04, r = 0.47). Sleep duration measured by the actigraphy watches was not significantly correlated with self-reported sleep duration (P = 0.65, r = 0.10). Ongoing assessment of sleep disturbances may be a valuable tool for informing the development of customized sleep interventions in a similar inpatient alcohol treatment sample.

Sleep homeostasis in alcohol-dependent, depressed and healthy control men

Visually scored and power spectral analyses (PSA) of polysomnography (PSG) recordings reveal abnormalities in alcohol dependence (AD) and major depressive disorder (MDD), including deficiencies in slow wave activity (SWA) during non-rapid eye movement (NREM) sleep. SWA parameters reflect the integrity of the homeostatic sleep drive, which have not been compared in those with AD or MDD. Ten men with AD were compared with 10 men with MDD and 10 healthy controls (HCs), all aged 20-40 years. They maintained an 11 pm to 6 am sleep schedule for 5-7 days, followed by 3 consecutive nights of PSG in the laboratory: night 1 for adaptation/screening; night 2 for baseline recordings; and night 3 as the challenge night, delaying sleep until 2 am. SWA was quantified with PSA across 4 NREM periods. Men with AD generated the least SWA at baseline. In response to sleep delay, HC men showed the expected SWA enhancement and a sharper exponential decline across NREM periods. Both the MDD and the AD groups showed a significantly blunted SWA response to sleep delay. Men with MDD had the least SWA in the first NREM period (impaired accumulation of sleep drive), whereas men with AD had the slowest SWA decay rate (impaired dissipation of sleep drive). These results suggest that both SWA generation and its homeostatic regulation are impaired in men with either AD or MDD. Finding interventions that selectively improve these different components of sleep homeostasis should be a goal of treatment for AD and MDD.

Novel pharmacotherapeutic treatments for cocaine addiction

Cocaine is a stimulant that leads to the rapid accumulation of catecholamines and serotonin in the brain due to prevention of their re-uptake into the neuron that released the neurotransmitter. Cocaine dependence is a public health concern and cause of significant morbidity and mortality worldwide. At present, there are no approved medications for the treatment of this devastating illness, and behavioral interventions have proven to be of limited use. However, there have been a number of recent trials testing promising agents including dopamine agonists, GABAergic medications and the cocaine vaccine. Here we discuss the most recent human clinical trials of potential medications for treatment of cocaine dependence, as well as pre-clinical studies for another promising agent, levo tetrahydropalmatine. Examination of these recent findings shows promise for GABAergic medications and the cocaine vaccine, as well as unique medications such as disulfiram, whose mechanism remains to be determined. Future work may also confirm specific subgroups of patients for treatment response based on clinical characteristics, biomarkers and pharmacogenetics. This review highlights the need for further, bigger studies in order to determine optimal clinical usage.

Circadian rhythms, sleep, and substance abuse

Substance abuse is linked to numerous mental and physical health problems, including disturbed sleep. The association between substance use and sleep appears to be bidirectional, in that substance use may directly cause sleep disturbances, and difficulty sleeping may be a risk factor for relapse to substance use. Growing evidence similarly links substance use to disturbances in circadian rhythms, although many gaps in knowledge persist, particularly regarding whether circadian disturbance leads to substance abuse or dependence. Given the integral role circadian rhythms play in regulating sleep, circadian mechanisms may account in part for sleep-substance abuse interactions. Furthermore, a burgeoning research base supports a role for the circadian system in regulating reward processing, indicating that circadian mechanisms may be directly linked to substance abuse independently of sleep pathways. More work in this area is needed, particularly in elucidating how sleep and circadian disturbance may contribute to initiation of, and/or relapse to, substance use. Sleep and circadian-based interventions could play a critical role in the prevention and treatment of substance use disorders.