Os derivados nitrados e oxigenados de hidrocarbonetos policíclicos aromáticos, nitro-HPA e oxi-HPA, podem ser encontrados no material particulado atmosférico e são provenientes da queima de combustíveis fósseis e biomassa, ou de reações dos HPA com gases atmosféricos. Determinados nitro-HPA e oxi-HPA apresentam mutagenicidade mais elevada do que a dos seus HPA precursores. O presente trabalho teve como objetivo avaliar os níveis de nitro-HPA e oxi-HPA nos extratos orgânicos do material particulado atmosférico das cidades de São Paulo, Araraquara, Paulínia e Piracicaba, durante períodos com e sem a queima da palha da cana-de-açúcar, verificar a possível existência de transporte de poluentes entre as regiões estudadas e determinar a mutagenicidade do material particulado. O material particulado atmosférico foi coletado em amostrador de grande volume com filtro de fibra de quartzo e extraído em Soxhlet. Os extratos foram submetidos à separação por HPLC, obtendo as frações de HPA, nitro-HPA e oxi-HPA, as quais foram analisadas por GC-MS. Tanto as frações como os extratos brutos foram submetidos a determinações gravimétricas e testes biológicos. Os nitro-compostos específicos, 1-nitropireno (1-NPir), 3-nitrofluoranteno (3-NFlt) e 6-nitrocriseno (6-NCri), para os quais há disponibilidade de padrões, foram analisados sendo que o 6-NCri não foi detectado em nenhuma amostra. Os níveis dos nitro-HPA encontrados (concentração máxima = 0,86 ngm-3) foram similares aos níveis reportados na literatura para diferentes cidades do mundo e o 3-NFlt apresentou níveis mais altos do que o 1-NPir em todas as amostras. Dentre os sítios estudados, São Paulo apresentou, em geral, níveis mais altos do que Araraquara, Piracicaba e Paulínia, apesar das concentrações altas de material particulado encontradas nesses três sítios. Em todos os sítios estudados houve um aumento nos níveis dos nitro-HPA no inverno, e não foi possível verificar se as emissões provenientes da queima da palha da cana-de-açúcar contribuem para os níveis desses poluentes. Na cidade de São Paulo, sítio mais estudado, foi observada uma variação sazonal evidenciada pelo aumento dos nitro-HPA no inverno de 2002. Níveis similares de nitro-HPA foram observados nos invernos de 2001 a 2004, exceto em 2003, onde os níveis foram mais altos devido provavelmente ao período longo de estiagem e às condições meteorológicas favoráveis à estagnação dos poluentes. Relacionando-se os níveis dos nitro-HPA com as trajetórias das massas de ar verificou-se um possível transporte de poluentes de uma região para outra em um único caso, de um total de 15. Dentre os oxi-HPA identificados (5H-fenantro(4,5-bcd)pirano-5-ona, 1-ácido fenantrenocarboxílico, 4H-ciclopenta(def)criseno-4-ona, 9,10-antracenodiona e benzantrona) a 9,10-antracenodiona e a benzantrona são comprovadamente mutagênicos. A benzantrona foi a mais freqüentemente encontrada nas amostras. Os níveis mais altos de oxi-HPA foram encontrados nas amostras de Araraquara e Piracicaba. Por final, pode-se concluir também, que as mutagenicidades das frações nitro- e oxi-HPA são as principais responsáveis pela mutagenicidade do extrato bruto, uma vez que a mutagenicidade das frações HPA praticamente não contribuiu para a mutagenicidade total. / Nitrated and oxygenated derivatives of polycyclic aromatic hydrocarbons, nitro-PAH and oxi-PAH, can be found in the atmospheric particulate matter from the combustion of fossil fuel and biomass or as result of PAH reactions with atmospheric gases. Some nitro-PAH and oxi-PAH compounds present higher mutagenicity than their parent PAH. The objective of this research was to evaluate the nitro- and oxi-PAH levels in organic extracts of atmospheric particulate matter collected at the cities of Sâo Paulo, Araraquara, Piracicaba and Paulinia, over periods with and without sugar cane burning, to analyze the possible transport of pollutants at these regions and to determine the mutagenicity of the particulate matter . The atmospheric particulate matter was collected by high volume sampler over quartz fiber filter and extracted with soxhlet. Extracts were submited to HPLC to obtain PAH, nitro-PAH and oxi-PAH fractions, which were analyzed by the GC-MS. Both fractions and extracts were subjected to gravimetric determinations and biological tests. Specific compounds, 1-nitropyrene (1-NPir), 3-nitrofluoranthene (3-NFlt) and 6-nitrocrisene (6-NCri) were analyzed and only 6-NCri was not detected in any of the samples. The determined levels of nitro-PAH (maximum concentration = 0,86 ngm-3) were similar to that reported in the literature for other cities of the world. In all samples, the 3-NFlt level was higher than that of 1-NPir. Among the studied areas, São Paulo presented, in general, higher levels than Araraquara, Piracicaba and Paulinia, despite the high concentration of particulate matter found at these areas. All the studied sites presented higher levels of nitro-PAH during the winter, and it was not possible to verify if the emissions of sugar cane burning contribute to the levels of these pollutants. An increase of the nitro-PAH during the winter of 2002 was observed in São Paulo, the more deeply studied site, showing a seasonal variation. Similar levels of nitro-PAH were observed in the winter of 2001, 2002 and 2004. In 2003, the levels were even higher probably due to the long period without rain and favorable meteorological conditions to the stagnation of pollutants. Relating the nitro-PAH levels with the air masses trajectories, it was observed that the pollutants were transported from a region to another in only one out of the 15 studied cases. Among the oxi-PAH identified (5H-phenanthro(4,5-bcd)pyran-5-one, 1-phenanthene carboxylic acid, 4H-ciclopenta(def)crisene-4-one, 9,10-anthracenedione and benzanthrone), the 9,10-anthracenedione and benzanthrone are mutagenic and were found in the most of the samples. Finally, the mutagenicity of the nitro-PAH and oxi-PAH fractions accounted for the mutagenicity of the organic extract, due to the fact that the mutagenicity of the PAH fractions was very low and its contribution to the total mutagenicity was negligible.

Background: Studies with experimental administration of alcohol offer inconsistent approaches and interpretations in which ways an acute alcohol exposure affects the HPA-system and the cortisol secretion. So far published alcohol experiments differ in alcohol application, the possibility of alcohol self-administration at the subjects own discretion as well as the age of the participants. Question: Is cortisol secretion modified by gender during alcohol infusion? Do men and women show different cortisol levels under alcohol exposure when compared to the baseline? Is there a dose-response relationship between cortisol secretion and acute alcohol exposure? Have family history, smoking habits and alcohol induced side effects like nausea an influence on the cortisol secretion under alcohol exposure? Materials and methods: 48 18 year old subjects participated in two identical sessions in which they were able to regulate their maximum blood alcohol concentration up to a safety limit of 1.2 ‰ (i.e., 0.12%). The experiment was conducted by using a special software for self-infusion of ethanol (CASE) which guided the participants through a two and a half hours long experiment. CASE is founded on a validated physiologically-based pharmacokinetic model and involves calculating the infusion volume needed to increase the blood alcohol concentration in a linear manner. The BAC increases after each alcohol request by 0,075 ‰ (i.e., 0.0075%) within in two and a half minutes. If the subject infuses no alcohol the blood alcohol concentration will decrease by 0.01 ‰ (i.e., 0.001%) per minute. Through the precise calculation of the infusion rate, individual differences can be eliminated. Cortisol levels were measured at five time points: an initial baseline measurement and four measurements at fixed time points during the alcohol self-administration of subjects with two completed alcohol experiments. As an appropriate measure to examine the effect of alcohol self-administration on cortisol secretion, the maximum blood alcohol concentration was determined. In addition the day of experiment, gender and family history were observed as well as exploratory maximum nausea and smoking habits. Results: In conclusion, the results confirmed that women have higher cortisol levels than men at baseline and under alcohol influence. Blood alcohol concentration as examined influencing variable was shown to have different effects on the HPA system on day one and two. On the first day of experimentation there was no effect of blood alcohol concentration on the HPA system. On the second day a dose-response relationship could be identified between cortisol secretion and acute alcohol exposure. Individually higher blood alcohol concentrations attenuated cortisol stronger in comparison to subjects with lower blood alcohol concentrations. Family history, smoking habits and unpleasant side effects (nausea) did not affect the cortisol secretion under alcohol exposure in this series of experiments. Conclusions: Current data suggests that alcohol experiments affect the cortisol secretion in young social drinkers. These findings could be detected for the first time. Up to this point there has not been an experimental study that investigated and evaluated the dose-effect relationship between cortisol secretion and alcohol in a study design which uses intravenous alcohol self-administration. It can be theorized that the first day of experimentation is suitable as a settling-in phase due to unspecific confounding factors, whereas the second day can be considered, in an identical setting, apt for hypothesis testing. The increased cortisol level in women when compared to men is consistent with previous studies and there was no indication that family history, smoking habits and alcohol induced unpleasant side effects have an influence on cortisol secretion.:Inhaltsverzeichnis 3 Abbildungsverzeichnis 6 Tabellenverzeichnis 7 Abkürzungsverzeichnis 8 1 Einleitung 10 1.1 Alkohol – eine kurze Einführung 10 1.2 Bedeutung des Zusammenhangs von HPA-System und Alkohol 12 1.2.1 Experimentelle Alkoholselbstverabreichung 12 1.2.2 Neuropharmakologie von Alkohol 13 1.2.3 Geschlechtsunterschiede bei der Cortisolsekretion 14 1.2.4 Übelkeit und die Auswirkungen auf die Cortisolsekretion unter Alkoholexposition 15 1.3 Orale Alkoholverabreichung versus intravenöse Alkoholverabreichung 16 1.4 Zielsetzung 19 2 Material und Methoden 20 2.1 Versuchsteilnehmer 20 2.1.1 Einschlusskriterien 20 2.1.2 Ausschlusskriterien 21 2.1.3 Aufnahmeuntersuchung 22 2.2 Versuchsaufbau und Durchführung 22 2.2.1 Versuchsprinzip 23 2.2.2 Versuchsablauf 24 2.2.3 Verwendete Materialien 27 2.2.4 CASE Software 27 2.2.5 Herstellung der 6%igen Alkohol-Infusionslösung 29 2.2.6 Messung der BAK 30 2.2.7 Verwendete Fragebögen und Selbsteinschätzungstests 30 2.3 Blutverarbeitung 31 2.3.1 Blutbehandlung im Labor (Testkit der Firma IBL International GMBH) 32 2.3.1.1 Testprinzip im Labor 32 2.3.1.2 Testdurchführung bei Serumproben 32 2.3.1.3 Testauswertung 33 2.4 Statistische Auswertung 33 3 Ergebnisse 37 3.1 Versuchsteilnehmer 37 3.2 Konfirmatorische Datenanalyse der Cortisolsekretion 38 3.2.1 CASE Ergebnisvariablen 38 3.2.2 Analyse von Baseline Cortisol Tag eins vs. Tag zwei 39 3.2.3 Einfluss von Familienanamnese, Geschlecht und maximalem Blutalkohol auf die Cortisolsekretion 40 3.2.3.1 Beobachtung beider Experimentaltage zusammen 40 3.2.3.2 Getrennte Beobachtung für den ersten Experimentaltag 44 3.2.3.3 Getrennte Beobachtung für den zweiten Experimentaltag 46 3.2.3.4 Einfluss von max BAK Tag zwei auf den prozentualen Anteil der Nettofläche an der Gesamtfläche Tag zwei 48 Explorative Analyse von potentiellen weiteren Einflussfaktoren 49 3.3.1 Der Effekt von Übelkeit auf die Cortisolsekretion 49 3.3.2 Der Effekt von Rauchen auf die Cortisolsekretion 50 4 Diskussion 52 4.1 Auswahl der CASE Ergebnisvariablen 52 4.2 Unterschiede zwischen dem ersten und zweiten Experimentaltag 53 4.3 Verschiedene Einflüsse auf die Cortisolsekretion 54 4.3.1 Einfluss von Geschlecht 54 4.3.2 Einfluss von max BAK 55 4.3.3 Einfluss von Familienanamnese 55 4.4 Unterschiede zu vorhergehenden Studien 56 4.5 Diskussion der explorativen Datenanalyse 57 4.5.1 Einfluss von Übelkeit auf die Cortisolsekretion 57 4.5.2 Einfluss von Rauchen auf die Cortisolsekretion 58 4.6 Limitation der D-LAYA Studie 59 4.7 Ausblick 60 Zusammenfassung 61

Die depressive Störung stellt eine weltweit häufige Erkrankung dar, die trotz vieler therapeutischer Optionen zu chronischen Verläufen und Non-Response neigt. Zirka 30 bis 50% der Patienten mit einer akuten Depression respondieren nicht auf eine Behandlung mit einem Antidepressivum trotz ausreichender Dauer und Dosis, so dass nach neuen pharmakologischen Ansätzen gesucht wird. Zudem sind Prädiktionsmöglichkeiten, was wem wann hilft, kaum vorhanden, so dass die klinische Praxis ein Versuchs- und Irrtumsverfahren ist. Ätiologisch gibt es gut dokumentierte neuroendokrinologische Befunde, die für eine Dysregulation der Hypothalamus-Hypophysen-Nebennierenrinden-Achse (HPA-Achse) im Sinne einer erhöhten Aktivität und einer erhöhten Auslenkbarkeit bei Depressionen sprechen. Für verschiedene antidepressive medikamentöse Therapien ist eine Normalisierung dieser Dysregulation beschrieben worden. Der sensitivste und spezifischste Test zur Untersuchung der HPA-Achse bei psychiatrischen Patienten ist der kombinierte Dexamethason/CRH-Test. Hierbei zeigen Patienten während der depressiven Phase eine deutliche Überstimulierbarkeit, d. h. bei depressiven Patienten führte die Gabe von Dexamethason mit anschließender CRH-Injektion zu einer überschießenden ACTH- und auch Cortisol-Antwort. Der Einfluss einer Behandlung mit Antidepressiva auf die HPA-Achse und der Zusammenhang möglicher Veränderungen der HPA-Achsen-Regulation mit dem Ansprechen oder Nicht-Ansprechen auf die Pharmakotherapie ist noch unzureichend beforscht. Teilweise gibt es sogar divergierende Befunde. In der vorliegenden Arbeit wurde mit Hilfe des Dexamethason/CRH-Tests der Einfluss einer antidepressiven Pharmakotherapie mit Citalopram auf die Regulation der HPA-Achse bei 30 vorwiegend unbehandelten Patienten mit einer Majoren Depression untersucht. Die SSRI sind die am häufigsten angewendeten Antidepressiva. Citalopram ist neben seinem S-Enantiomer Escitalopram der selektivste SSRI, der gewählt wurde, um gezielt die Auswirkungen einer rein serotonergen antidepressiven Behandlung zu untersuchen. Vor Beginn der Therapie und nach vierwöchiger Behandlung wurden mittels kombinierten Dexamethason/CRH-Tests bei den Patienten Cortisol- und ACTH-Konzentrationen im Serum gemessen. Die Diagnosen wurden mit SKID I und II bestätigt. Im wöchentlichen Rhythmus wurde während des vierwöchigen Studienverlaufs die aktuelle depressive Symptomatik sowie der Gesamtkrankheitszustand der Patienten mittels Selbst- (BDI) und Fremdratingbögen(HAM-D, CGI) erhoben. Ebenfalls im wöchentlichen Rhythmus wurden medikamentenassoziierte Nebenwirkungen systematisch erfasst. Unter der Behandlung zeigten sich erfreulich viele Responder auf die antidepressive Pharmakotherapie mit Citalopram (23 von 30 Patienten). Eine Herabregulierung der HPA-Achse zeigte sich unter der Behandlung nur auf der Hypophysenebene für die ACTH-Antwort, allerdings nicht auf der Nebennierenrindenebene für die Cortisol-Antwort. Trotz geringerer ACTH-Konzentrationen wurde nach vier Wochen noch die gleiche Menge an Cortisol in der Nebennierenrinde produziert. Die AUC total für ACTH betrug vor der antidepressiven Behandlung mit Citalopram 2077 ± 1260. Nach vier Wochen antidepressiver Pharmakotherapie zeigte sich ein Wert von 1393 ± 485 und damit ein signifikanter Unterschied (p=0,010). Für die AUC total für Cortisol zeigte sich wie bereits erwähnt kein signifikanter Unterschied (AUC total vor Behandlung: 4755 ± 3411 und nach vier Wochen Behandlung: 4901 ± 3688; p=0,813). Möglicherweise ist dies auf einen direkten Effekt von Citalopram auf die Nebennieren im Sinne einer Sensibilisierung zu verstehen. Wirkungen in dieser Richtung wurden bislang nicht beschrieben. Ein prädiktiver Wert für das Ansprechen auf die Behandlung konnte für den Dex/CRH-Test nicht gefunden werden. Responder und Non-Responder unterschieden sich nicht. Auch das aufwendige Procedere des Testes limitiert ihn für eine regelhafte Anwendung in der Klinik. Allerdings besteht weiterhin in diesem Bereich Forschungsbedarf, um die unterschiedlichen Befunde einordnen zu können. Dabei wären z. B. Studien mit einer größeren Fallzahl sowie ein Vergleich mit einer Placebobehandlung wünschenswert.

Soziale Ausgrenzung ist ein wesentlicher emotionaler Stressor. Ziel der Arbeit war die Erfassung hormoneller Prozesse nach cyberball-induzierter sozialer Ausgrenzung sowie nachfolgendem TSST, Frauen zeigen nach sozialer Ausgrenzung eine Aktivierung der HPA-Achse im Sinne eines verstärkten ACTH-Anstieges im Gegensatz zu den integrierten Frauen oder männlichen Testpersonen.

Familial risk and environmental stress promote the development of alcohol dependence. We investigated whether a positive family history of alcoholism affects the neuroendocrine response to a standardized laboratory stress test in healthy subjects without alcohol use disorders. Twenty-four high-risk subjects with a paternal history of alcoholism (PHA) and 16 family history negative (FHN) controls were evaluated. Psychosocial stress was induced by having subjects deliver a 5-min speech and mental arithmetics in front of an audience on separate days, after drinking either placebo or ethanol (0.6 g/kg) in a randomized sequence. Adrenocorticotropin (ACTH) was measured in 10 plasma samples covering up to 75 min after the stress test. Plasma arginine vasopressin (AVP) was determined before the stressor, at the time of maximum ACTH secretion, and at 75 min after stress onset. The stress test induced a phasic increase in ACTH secretion. At the time of maximum ACTH, AVP was significantly increased in relation to baseline. Compared to placebo, alcohol administration significantly attenuated maximum ACTH concentration in PHA but not FHN subjects, and decreased AVP measured in the same samples in PHA but not FHN subjects. We conclude that activation of the hypothalamic–pituitary–adrenal system by psychosocial stress is accompanied by an increase in peripheral plasma AVP levels. Secretion of both ACTH and AVP suggest that alcohol attenuates the stress response selectively in PHA but not FHN subjects. This might imply some short-term positive alcohol effect in sons of alcoholics, but also constitute a mechanism by which their risk to develop alcohol use disorders is increased.

Les nouveaux neurones de l’hippocampe semblent contribuer à l’action thérapeutique des antidépresseurs. La nature fonctionnelle de cette contribution est cependant inconnue. En stimulant la neurogenèse les antidépresseurs pourraient renforcer certaines fonctions de l’hippocampe et ainsi permettre la rémission. Nous montrons dans ce travail que les nouveaux neurones peuvent contribuer à l’action thérapeutique des antidépresseurs en participant au renforcement de rétrocontrôle hippocampique sur la régulation de l’axe HPA, potentiellement via leur rôle dans la capacité de l’hippocampe à moduler l’activité des autres structures impliquées dans la régulation du stress, comme le noyau du lit de la strie terminale. Les différentes composantes fonctionnelles de l’hippocampe sont cependant topographiquement distribuées le long de son axe septo-temporal. A travers une approche corrélative nous avons montré que différents antidépresseurs régulent la neurogenèse différentiellement le long de l’axe septo-temporal. Cela suggère des mécanismes de régulation régiondépendants et que la contribution des nouveaux neurones dans les effets des antidépresseurs pourrait être multiple et sous tendue par des composantes fonctionnelles différentes, et non limitée à la régulation de l’axe du stress. / Hippocampal newborn neurons contribute to some extent to the therapeutic effects of antidepressants. Mechanisms involved in this contribution remain however elusive. By increasing the recruitment of newborn neurons antidepressants could improve several hippocampal functions and thus allow remission. Here we demonstrate that newborn neurons may contribute to the therapeutic effects of antidepressants by allowing the recovery of a proper hippocampal inhibitory feedback over the HPA axis, possibly by normalizing the communication between the hippocampus and stress integrative structures mediating its inhibitory influence, such as the bed nucleus of the stria terminalis. Hippocampal functions are however topographically segregated along its septo-temporal axis. Here we show that different mood-improving manipulations differentially regulate neurogenesis along this septo-temporal axis. This suggest different region-specific mechanisms involved in the regulation of neurogenesis and that newborn neurons may contribute to the therapeutic effects of antidepressants by modulating different aspects of hippocampal functions.

Parental divorce has not only been associated with negative long-term effects for children of divorce (CD), but also for adult children of divorce (ACD). ACD more often have poorer mental well-being than adult children of marriage (ACM). Neurological research further suggests that ACD have lower baseline levels of the “stress hormone” cortisol. However, research of Swedish ACD is extremely sparsely. Therefore, the study’s aim is to examine the possible long-term effects of Swedish ACD. Do ACD have lower well-being and experience more stress than ACM? A sample of 227 Swedish participants (81 ACD and 146 ACM) were included. The majority (75.7%) were between 18-30 years old, 157 females and 70 males. An online survey including the Perceived Stress Scale (PSS), the Temporal Satisfaction with Life Scale (TSWLS), and questions about the parental divorce was distributed via social media. Independent t-tests and one-way ANOVA analysis were performed to compare ACD’s and ACM’s results. The study found that ACD rated their well-being (satisfaction with the past) (p ≤ .001), and stress (p ≤ .019), significantly lower than ACM. Moreover, female ACD perceived more stress than female ACM (p ≤ .010), and male ACD (p ≤ .015). The group between 10-14-year-old at the time of the divorce rated significantly lower well-being (past) (p ≤ .035). In conclusion, the study suggests that Swedish ACD also suffer from long-term effects of divorce. Future research ought to investigate the matter further. / Skilsmässa har inte bara visat negativa långsiktiga effekter för skilsmässobarn (CD), utan också för vuxna skilsmässobarn (ACD). ACD har oftare ett sämre mentalt välbefinnande än vuxna med gifta föräldrar (ACM). Neurologisk forskning vidare påvisar att ACD också har lägre grundnivåer av ”stresshormonet” kortisol. Forskning kring svenska ACD är extremt sällsynt. Därför är det studiens mål att undersöka de möjliga långsiktiga effekterna av svenska ACD. Har ACD ett längre välbefinnande och upplever mer stress än ACM? Ett urval av 227 svenska deltagare (81 ACD och 146 ACM) var inkluderade. Majoriteten (75.7%) var mellan åldrarna 18-30 år gamla, 157 kvinnor och 70 män. En online enkät innehållandes Perceived Stress Scale (PSS), Temporal Satisfaction with Life Scale (TSWLS), och frågor kring skilsmässan distribuerades via sociala medier. Independent t-tests och one-way ANOVA analyser tillämpades för att jämföra ACD:s och ACM:s resultat. Studien fann att ACD uppskattade att deras välbefinnande (tillfredställelse med det förflutna) (p ≤ .001), och stress (p ≤ .019) signifikant längre än ACM. Fortsättningsvis, en signifikant skillnad upptäcktes där kvinnliga ACD upplevde mer stress än kvinnliga ACM (p ≤ .010), och manliga ACD (p ≤ .015). Gruppen mellan åldrarna 10–14 år gamla vid skilsmässan uppgav ett signifikant längre välbefinnande (förflutet) (p ≤ .035). Sammanfattningsvis, studien påvisar att svenska skilsmässobarn också lider av långsiktiga effekter från skilsmässa. Framtida forskning bör undersöka området vidare.

Bakgrund: Sömnproblem är ett utbrett problem och är oftast en del av vissa livsstilssituationer där jobb, familjeliv och sjukdom kan påverka sömnen negativt. Fysisk aktivitet är en strategi för att förbättra sömnen, men vid tillfällen där aktiv rörelse inte är möjlig kan avslappningstekniker användas. Yoga nidra, även kallad yogisk sömn, är en guidad meditationsteknik som involverar många olika avslappningstekniker. En effekt av yoga nidra tycks vara ökad parasympatisk aktivitet och minskad sympatisk aktivitet. Syfte: Syftet med studien var att undersöka yoga nidras påverkan på sömnen på vuxna individer.                                                                                                          Metod: En systematisk litteraturstudie baserad på vetenskapliga artiklar publicerade 2019-2024. Databaserna PubMed och Web of Science användes för litteratursökningen. Resultat: Sex artiklar mötte inklusionskriterierna. Samtliga studier var experimentella. Fem av studierna visade på signifikant förbättrad sömn efter upprepad intervention. En studie gav oförändrad effekt efter en yoga nidra session.                                  Slutsats: Resultatet från litteraturstudien tyder på att yoga nidra kan inverka positivt på sömnen om interventionen utförs kontinuerligt. Dock rådde heterogenitet bland artiklarna gällande studiens kvalitet, population och interventionens längd, vilket försvårar tolkning av resultat. Bättre och mer enhetliga studier samt fler deltagare behövs för att kunna påvisa ett samband. / Background: Sleep problems are widespread and are usually part of certain lifestyle situations where work, family life and illness can affect sleep negatively. Physical activity is one strategy to improve sleep, but relaxation techniques can be used when active movement is not possible. Yoga Nidra, or yogic sleep, is a guided meditation technique that involves many different relaxation methods. One effect of yoga nidra appears to be increased parasympathetic activity and decreased sympathetic activity. Aims: The study aimed to examine the effect of yoga nidra on sleep in adults. Methods: A systematic literature study based on scientific articles published 2019-2024. The literature search was done using Pub Med and Web of Science databases. Results: Six articles met the inclusion criteria and were included in the study. All studies were experimental. Five of the studies showed significantly improved sleep after repeated intervention. One study found an unchanged effect after only one yoga nidra session. Conclusions: The results from the literature study indicate that yoga nidra may have a positive effect on sleep if the intervention is carried out over a period of time. However, there was heterogeneity among the articles regarding the study quality, population and intervention length, making it difficult to assess the results. Better and more unitary studies and more participants are needed to determine a connection.

Mental toughness has received extensive research attention in recent years because of its intuitive and theoretical association with successful performance. However, several significant omissions in understanding remained. This thesis aimed to address these gaps through various research approaches and methodologies, collectively resulting in a biopsychological perspective. The primary objectives were to provide a more holistic perspective of mental toughness and generate quantitative support for the various biological (2D:4D) cognitive-affective (self-structure), physiological (cortisol response) and behavioural (performance) differences that have been associated with the construct. The findings suggested that mental toughness is a multifaceted construct and manifests in several areas of human functioning; specifically, a particular cognitive-affective profile may underlie mental toughness (they possess a positive self-concept and a particular self-structuring style, namely integration). Furthermore, levels of cortisol during a competitive event (a physiological indicator of perceived stress levels) were significantly negatively related to mental toughness, suggesting that mentally tough individuals have a reduced perception of threat in competitive situations (giving support for the notion that they perceive competition or stress as a potential challenge for personal growth and improvement). An objective marker of mental toughness was also supported; specifically, 2D:4D ratio (indicative of prenatal testosterone levels) related significantly with scores on a mental toughness scale, giving support for the biological underpinning of the construct and an objective marker of mental toughness. Finally, two case examples are provided to demonstrate the usability of these important markers (cognitive, biological and physiological) in an applied context.

The Hypothalamus-Pituitary-Adrenal axis (HPA-axis) with its end product cortisol mediates the physiological response to stress thereby promoting mobilization of energy. The cortisol levels follow a diurnal rhythm with a distinct awakening response. Regulation of the HPA-axis differs among persons with certain psychiatric disorders when compared with controls. Some reports concern Attention-Deficit/Hyperactivity Disorder (ADHD) but findings are inconclusive. The main aim of the present thesis was to investigate diurnal levels of saliva cortisol in school aged children with ADHD and age matched non-affected comparisons, also taking early adversity, perceived stress and ADHD-medication into consideration. Children with ADHD had lower cortisol levels at awakening, 30 minutes later and before going to bed than comparisons. When the study group was split into three different age groups similar results were found only for children above 10 years of age. Within the ADHD group, subtype of ADHD or co-occurring symptoms did not affect the cortisol levels. Furthermore, children in the ADHD group had to a higher degree been exposed to foetal and childhood psychosocial adversity than comparisons. Since exposure to early adversity has been associated with both ADHD and HPA-axis functioning, such exposures could theoretically explain the low cortisol levels in ADHD via early programming of the HPA-axis. However, no relation was found between exposures to psychosocial adversity and diurnal cortisol levels. Neither did continuous medication with stimulants or atomoxetine explain the low cortisol levels. Possibly, medication may rather increase the levels. Finally, children with ADHD scored higher on perceived stress, measured by the Pressure-Activation-Stress (PAS) scale, than the comparison group. Female sex was also associated with higher stress in both groups, as well as increasing age in the comparison group. As with psychosocial adversity, no association was found between the higher PAS-scores and the lower cortisol levels, indicating the complexity of the stress regulating system. The results indicate a down-regulated or displaced HPA-axis with lower cortisol levels in children with ADHD. Stress related fragility – with more exposure to early stressors, higher perceived stress and lower diurnal cortisol levels – seem to accompany ADHD during childhood.