Effects of long-term administration of nicotine and fluoxetine on sleep in depressed patients

Pathophysiology of nAChRs: limbic circuits and related disorders

Human epidemiological studies have identified links between nicotine intake and stress disorders, including anxiety, depression and PTSD. Here we review the clinical evidence for activation and desensitization of nicotinic acetylcholine receptors (nAChRs) relevant to affective disorders. We go on to describe clinical and preclinical pharmacological studies suggesting that nAChR function may be involved in the etiology of anxiety and depressive disorders, may be relevant targets for medication development, and may contribute to the antidepressant efficacy of non-nicotinic therapeutics. We then review what is known about nAChR function in a subset of limbic system areas (amygdala, hippocampus and prefrontal cortex), and how this contributes to stress-relevant behaviors in preclinical models that may be relevant to human affective disorders. Taken together, the preclinical and clinical literature point to a clear role for ACh signaling through nAChRs in regulation of behavioral responses to stress. Disruption of nAChR homeostasis is likely to contribute to the psychopathology observed in anxiety and depressive disorders. Targeting specific nAChRs may therefore be a strategy for medication development to treat these disorders or to augment the efficacy of current therapeutics.

Transdermal nicotine in non-smokers: A systematic review to design COVID-19 clinical trials

Recent data show an interaction between COVID-19 and nicotine and indicate the need for an assessment of transdermal nicotine use in non-smokers. Assessments have been conducted into the short-term cognitive effects of nicotine and into diseases such as Parkinson's, Tourette syndrome, ADHD or ulcerative colitis.

METHODS

Analyses of nicotine administration protocols and safety were conducted after reviewing Medline and Science Direct databases performing a search using the words [transdermal nicotine] AND [non-smoker] AND selected diseases.

RESULTS

Among 298 articles identified, there were 35 reviewed publications reporting on 33 studies of non-smokers receiving transdermal nicotine for >48hours. In the 16 randomized trials, 7 crossover, 1 case/control and 9 open studies patients received an initial nicotine dose of between 2.5mg and 15mg/day. In 22 studies, daily doses increased by 2 to 7 steps in 3 to 96 days until the dose was between 5mg and 105mg/day. The target nicotine dose was 19.06±20.89mg/day. The 987 non-smokers (534 never-smokers, 326 ex-smokers and 127 classified as "non-smokers") received or did not receive nicotine. The most common side-effects were nausea and skin itching. Forty-three (7.1%) non-smokers stopped treatment because of an adverse event of nicotine. No hospitalization related to nicotine side-effects were reported.

CONCLUSION

Despite a relatively safe tolerance profile, transdermal nicotine therapy in non-smokers can only be used in clinical trials. There is a lack of formal assessment of the potential risk of developing a tobacco addiction. This review offers baseline data to set a transdermal nicotine protocol for non-smokers with a new purpose.

Prevalence and risk factors of excessive daytime sleepiness in major depression: A study with 703 individuals referred for polysomnography

BACKGROUND

To date, few studies have investigated the prevalence and risk factors of excessive daytime sleepiness (EDS) in major depression. Thus, the aim of the present study was to examine the prevalence and risk factors of EDS in a large sample of individuals with major depression.

METHODS

Data from 703 individuals with major depression were retrospectively collected from the sleep laboratory research database of Erasme Hospital for analysis. A score of > 10 on the Epworth Sleepiness Scale was used as the cut-off for EDS. Logistic regression analyses were conducted to examine the clinical and demographic risk factors of EDS in major depression.

RESULTS

The prevalence of EDS in our sample was 50.8%. Multivariate logistic regression analysis revealed that the following were significant risk factors of EDS in major depression: non-use of short to intermediate half-life benzodiazepine receptor agonists, BMI ≥ 25 kg/m², age < 60 years, C-reactive protein > 7 mg/L, Beck Depression Inventory score ≥ 16, atypical depression, apnea-hypopnea index ≥ 15/h, and use of selective serotonin reuptake inhibitors or serotonin-norepinephrine reuptake inhibitors.

LIMITATIONS

To evaluate EDS, we used the Epworth Sleepiness Scale, which only allows for a subjective measure of daytime sleepiness.

CONCLUSION

EDS is a common symptom in individuals with major depression. In this subpopulation, interventions are possible for most risk factors of EDS, which justifies improved management of this symptom to avoid its negative consequences.

Transdermal Nicotine for the Treatment of Mood and Cognitive Symptoms in Nonsmokers With Late-Life Depression

OBJECTIVE

Late-life depression (LLD) is characterized by poor antidepressant response and cognitive dysfunction. This study examined whether transdermal nicotine benefits mood symptoms and cognitive performance in LLD.

METHODS

In a 12-week open-label outpatient study conducted between November 2016 and August 2017, transdermal nicotine was given to 15 nonsmoking older adults (≥ 60 years of age). Eligible participants met DSM-IV-TR criteria for major depressive disorder with ≥ 15 on the Montgomery-Asberg Depression Rating scale (MADRS) and endorsed subjective cognitive impairment. Transdermal nicotine patches were applied daily and titrated in a rigid dose escalation strategy to a maximum dose of 21.0 mg/d, allowing dose reductions for tolerability. The primary mood outcome was MADRS change measured every 3 weeks, with response defined as ≥ 50% improvement from baseline and remission as MADRS score ≤ 8. The primary cognitive outcome was the Conners Continuous Performance Test (CPT), a test of attention.

RESULTS

Robust rates of response (86.7%; 13/15 subjects) and remission (53.3%; 8/15 subjects) were observed. There was a significant decrease in MADRS scores over the study (β = -1.51, P < .001), with improvement seen as early as 3 weeks (Bonferroni-adjusted P value = .004). We also observed improvement in apathy and rumination. We did not observe improvement on the CPT but did observe improvement in subjective cognitive performance and signals of potential drug effects on secondary cognitive measures of working memory, episodic memory, and self-referential emotional processing. Overall, transdermal nicotine was well tolerated, although 6 participants could not reach the maximum targeted dose.

CONCLUSIONS

Nicotine may be a promising therapy for depressed mood and cognitive performance in LLD. A definitive placebo-controlled trial and establishment of longer-term safety are necessary before clinical usage.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02816138​.

Hyperarousal during sleep in untreated, major depressed subjects with prodromal insomnia: A polysomnographic study

In primary insomnia, specific dynamics of hyperarousal are evident during the night. Similarly, in major depression, many elements also favor of the presence of hyperarousal. Thus, it would be interesting to investigate if hyperarousal presents the same dynamic in major depression. Polysomnographic data from 30 healthy controls, 66 patients with major depression and prodromal insomnia, and 86 primary insomnia sufferers recruited from the sleep laboratory database were studied for whole night and thirds of the night. Insomnia sufferers and patients with depression exhibit a similar polysomnographic pattern both for whole night (increased sleep latency and WASO and reduced SWS and REM) and thirds of night (increased WASO at first and last thirds, reduced SWS in first third, and reduced in REM in first and last third). No alterations were detected during the second third of the night. Just as in primary insomnia, the hyperarousal phenomenon is found mainly in major depression with prodromal insomnia during the sleep-onset period and the first and last thirds of the night, but lesser during the second third of the night. These specific dynamics of hyperarousal may aid in the understanding of the particular relationship between insomnia and depression.

Nicotine and networks: Potential for enhancement of mood and cognition in late-life depression

Late-life depression is characterized by both lower mood and poor cognitive performance, symptoms that often do not fully respond to current antidepressant medications. Nicotinic acetylcholine receptor (nAChR) agonists such as nicotine may serve as a novel therapeutic approach for this population. Both preclinical and preliminary clinical studies suggest that nAChR agonists can improve depressive behavior in animal models and improve mood in depressed individuals. Substantial literature also supports that nAChR agonists benefit cognitive performance, particularly in older populations. These potential benefits may be mediated by the effects of nAChR stimulation on neural network function and connectivity. Functional neuroimaging studies detail effects of nAChR agonists on the default mode network, central-executive network, and salience network that may oppose or reverse network changes seen in depression. We propose that, given the existent literature and the clinical presentation of late-life depression, nicotine or other nAChR agonists may have unique therapeutic benefits in this population and that clinical trials examining nicotine effects on mood, cognition, and network dynamics in late-life depression are justified.

Ansiedade e baixo nível motivacional associados ao fracasso na cessação do tabagismo

Objetivo Analisar a associação entre as características sociodemográficas, status do tabagismo, grau de motivação, nível de ansiedade, depressão e de estresse com o fracasso em pacientes de um programa de cessação de tabagismo. Métodos Estudo de corte transversal realizado com pacientes que procuraram os programas de cessação do tabagismo de Cuiabá/MT, Brasil. Todos os fumantes matriculados no início desses programas, durante o período de maio a agosto de 2012, foram convidados a participar deste estudo, totalizando 216 pacientes. Os instrumentos utilizados foram o questionário Perfil Sociodemográfico, Teste de Fagerström (FTND), URICA, Inventário de Ansiedade de Beck (BAI), Inventário de Depressão de Beck (BDI) e Inventário de Sintomas de Stress de Lipp (ISSL). Os dados foram digitados duplamente em programa Epidata versão 3.1, e para análise dos dados foi utilizado um modelo de regressão de Poisson. Resultados Foram encontradas associações do fracasso terapêutico com as seguintes variáveis: faixa etária jovem (RP = 1,68; IC 95% 1,11-2,56); menor tempo de tabagismo (RP = 1,32; IC 95% 1,09-1,61); maior consumo de cigarros/dia (RP = 1,24; IC 95% 1,01-1,52) e menor grau de motivação (RP = 1,55; IC 95% 1,04-2,30). No modelo final (RPa), ficaram associadas ao fracasso as variáveis: menor tempo de tabagismo (RPa 1,53; IC 95% 1,07-2,32), maior carga tabágica (RPa 1,48; IC 95% 1,12-1,95), baixo nível de motivação (RPa 1,58; IC 95% 1,07-2,32) e alto nível de ansiedade (RPa 1,22; IC 95% 1,01-1,48). Conclusão Baixo nível motivacional (Contemplação e Pré-contemplação), alto nível de ansiedade (moderado/grave), menor tempo de tabagismo e alta carga tabágica estão associados ao fracasso terapêutico.

Sleep Organisation in Depression and Schizophrenia: Index of Endogenous Periodicity of Sleep as a State Marker [Retracted]

Background: Sleep disorders are frequent symptoms described in psychiatric patients with major depression or schizophrenia. These patients also exhibit changes in the sleep architecture measured by polysomnography (PSG) during sleep. The aim of the present study was to identify potential biomarkers that would facilitate the diagnosis based on polysomnography (PSG) measurements.Subjects and Methods: 30 patients with schizophrenia, 30 patients with major depression and 30 healthy control subjects were investigated in the present study. The mean age in the group with schizophrenia was 36.73 (SD 6.43), in the group of patients with depression 40.77 (SD 7.66), in the healthy controls group 34.40 (SD 5.70). The gender distribution was as follows: 18 male, 12 female in the group with schizophrenia; in the group of patients with depression 11 male, 19 female; in the control group 16 male and 14 female. All subjects underwent polysomnography (PSG) for a minimum time of 8 hours according to the criteria of Rechtschaffen & Kales (1968). The following polysomnographic (PSG) parameters were analyzed: sleep latency (SL), total sleep time (TST), waking time after sleep onset (WTASO), number of awakenings (NAW), slow wave sleep (SWS), rapid eye movement sleep (REM), rapid eye movement sleep latency (REML), first REM period (REM 1), and first NREM period (NREM 1). We tested the potential of multiple sleep variables to predict diagnosis in different groups by using linear discriminate analysis (LDA).Results: There were significant differences in polysomnography (PSG) variables between healthy control subjects and psychiatric patients (total sleep time, sleep latency, number of awakenings, time of awakening after sleep onset, REM 1 latency, REM 1 and index of endogenous periodicity). Importantly, LDA was able to predict the correct diagnosis in 88% of all cases.Conclusions: The presented analysis showed commonalities and differences in polysomnography (PSG) changes in patients with major depressive disorder and in patients with schizophrenia. Our results underline the potential of polysomnography (PSG) measurements to facilitate diagnostic processes.

Protective effect of nicotine on oxidative and cell damage in rats with depression induced by olfactory bulbectomy

We evaluated the effects of nicotine on cell and oxidative damage caused by olfactory bulbectomy (OBX). The rats were divided into seven groups as follows: i) control; ii) vehicle (6% ethanol); iii) treated with nicotine; iv) sham operated; v) olfactory bulbectomy (OBX); vi) OBX+vehicle; and vii) OBX+Nic. The OBX was performed using the trepanation of frontal bone. The olfactory bulbs were cut and removed without damage to the frontal cortex. Two weeks after surgery nicotine was administered chronically once daily for 14 days, intraperitoneally (i.p.) in doses of 1.5 mg/kg, two weeks after surgery. OBX caused an increase in lipid peroxidation products and caspase-3 but prompted a reduction in reduced glutathione (GSH) content and antioxidative enzyme activity. All these changes were reverted by treatment of nicotine (14 days). In conclusions: i) OBX induces oxidative stress and cell death by apoptosis; and ii) nicotine presents antidepressant and antioxidant effect. All these findings suggest that nicotine would be a therapeutic tool for depression, although more studies are needed in this area to define the appropriate treatment regime.

Antidepressant-like effects of nicotine and transcranial magnetic stimulation in the olfactory bulbectomy rat model of depression

In this study, we compared the depression-like symptoms induced by olfactory bulbectomy (OBX) in the two inbred Wistar and Long Evans rat strains. We also analyzed the self-regulated oral intake of nicotine in these strains and the effect of nicotine on the depression-like symptoms of olfactory bulbectomy. Furthermore, we compared the antidepressant-like effects of nicotine on Wistar rats to those of transcranial magnetic stimulation (TMS), which has emerged as a therapeutic alternative for depression management. Our results show that Wistar rats develop depression-like symptoms, demonstrated by the forced swim test (FST), 4 weeks after OBX. However, in bulbectomized Long Evans rats these symptoms cannot be assessed due to a higher degree of variability of the swimming behavior of this strain. These results suggest that there are some innate differences in susceptibility to stress between these two rat strains. In Wistar rats, voluntary oral nicotine intake (1.2 mg/(kg day) for 14 days) as well as nicotine administered as a single daily i.p. injection (1.5 mg/(kg day) for 14 days) decrease the depression-like symptoms of OBX. Daily transcranial magnetic stimulation (60 Hz and 0.7 mT for 2h/day for 14 days) also decreases depression-like symptoms but is less effective than nicotine. In conclusion, our results support the idea that there are possible innate differences for depression susceptibility and that nicotine and TMS may be useful in the treatment of this syndrome.

Euphoriant effects of nicotine in smokers: fact or artifact?

RATIONALE

The claim that nicotine in cigarettes is euphoriant to smokers is largely based on two studies (Pomerleau and Pomerleau, Psychopharmacology, 108:460-465, 1992; Tobacco Control, 3:374, 1994) in which smokers were instructed to respond to sensations of rush, buzz, or high while smoking low-nicotine or regular cigarettes. However, the assumption that these sensations are pleasurable was not tested and may have biased the results.

OBJECTIVES

The aim of this study was to re-examine the claim that smoked nicotine is euphoriant to smokers.

METHODS

Study 1 surveyed the frequency and pleasantness of the smoking-related sensations of rush, buzz, and high in a sample of smokers. Study 2 replicated Pomerleau and Pomerleau (Psychopharmacology, 108:460-465, 1992) with two sets of instruction. One set, as in the original study, defined these sensations as pleasurable, whereas the other defined them as unpleasant.

RESULTS

Study 1 found that whereas rush and high were perceived as pleasant, buzz was unpleasant to most smokers. Study 2 found that under both sets of instructions, smokers reported more sensations when smoking the regular, as compared to the low-nicotine cigarette. Additionally, the sensations of rush, buzz, and high were rated as more pleasant under the pleasant instructions as compared to the unpleasant instructions. Finally, in the pleasant instructions condition, many participants reported having pressed the button to indicate a pleasurable sensation despite having actually experienced that sensation as unpleasant.

CONCLUSIONS

Our results suggest that the findings of Pomerleau and Pomerleau (Psychopharmacology, 108:460-465, 1992; Tobacco Control, 3:374, 1994) may have been biased by the experimental instructions and cannot be taken as evidence that smoked nicotine is euphoriant to smokers.

Acute psychomotor, subjective and physiological responses to smoking in depressed outpatient smokers and matched controls

RATIONALE

Cigarette smoking is highly prevalent in people diagnosed with depression, and depressed smokers are less likely to quit. Examining depressed smokers' responses to smoking will help determine the role of depression in maintaining cigarette smoking.

OBJECTIVES

To determine the psychomotor, subjective and physiological effects of cigarette smoking in currently depressed smokers versus matched controls.

MATERIALS AND METHODS

Fourteen currently depressed smokers and 14 never-depressed smokers, matched in age, gender, nicotine dependence and daily cigarette consumption, smoked three cigarettes at half-hourly intervals. All smokers were non-deprived. Self-reported mood and craving for cigarettes, performance on a simple reaction time task, expired-air carbon monoxide, heart rate and blood pressure were assessed before and after smoking each cigarette. Smoking topography was also assessed.

RESULTS

Depressives and controls did not differ in terms of dependence on cigarettes or expired-air carbon monoxide. Topographic and cardiovascular measures were similar in depressed and control participants, suggesting that they smoke cigarettes in a similar manner. However, depressives displayed enhanced reaction time performance after the first cigarette. Positively reinforced craving was reduced after smoking each cigarette but returned to baseline levels within 30 min in depressed but not in control smokers. Depressed smokers also displayed higher levels of negatively reinforced craving. Both depressives and controls reported improved positive mood after smoking.

CONCLUSIONS

Cigarette smoking in non-deprived depressed smokers enhances psychomotor performance and the reduction of positively reinforced craving in depressed smokers after smoking is transient, suggesting that enhanced craving may play a role in the maintenance of smoking in depression.