Females are disproportionately affected by stress- related mood disorders. Child abuse is the single greatest environmental risk factor for mood disorders. An animal model of child abuse, juvenile social subjugation (JSS), was used to determine whether males and females differentially process stress, specifically in the bed nucleus of the stria terminalis (BST). Rats (n=36) were randomly assigned to one of three conditions: JSS, Benign Control (BC) or Handled Control (HC). Following this procedure, brains were processed for Fos, which indicates neural activity. It was hypothesized that the JSS condition would evoke more neural activation than other conditions and would do so more in females. Across both sexes, we hypothesized there would be significantly more activation in the posterior BST than in the anterior BST. Based on earlier research, we hypothesized there would be and a sex difference in total neuron number, favoring males, in the posterior BST.

There has recently been an intense debate about the increased rate of bipolar disorders (BPD) in children and adolescents observed in clinical settings. Thus, there is great interest in child and adolescent symptoms of hypomania and whether these symptoms subsequently will develop into BPD. More knowledge about early signs could give insight into the development of the disorder. There are also concerns that hypomanic symptoms in adolescence indicate excess risk of other health conditions. It has been reported that patients with mood disorders have a high consumption of prescription drugs in different ATC classes. The primary objective of this thesis was to better understand the mental health outcome of adolescents with hypomania spectrum symptoms and to identify early risk factors for adult bipolar disorder among adolescents with mood disorders. In order to widen the scope and investigate health outcome of mood disorder in general psychopharmacological outcomes were included. A community sample of adolescents (N=2 300) in the town of Uppsala, Sweden, was screened for depressive symptoms. Both participants with positive screening and matched controls (in total 631) were diagnostically interviewed. Ninety participants reported hypomania spectrum episodes, while another 197 fulfilled the criteria for major depressive disorder (MDD) without a history of a hypomania spectrum episode. A follow-up after 15 years included a blinded diagnostic interview, a self-assessment of personality disorders, and national register data on prescription drugs and health services use. Adolescent mood symptoms, non-mood disorders, and family characteristics were assessed. Univariate and multivariate analyses were used. The results indicate that the phenomenology of the hypomania spectrum episodes during childhood and adolescence per se does not predict adult bipolar disorder. However, having both affective symptoms during adolescence and a family history of bipolar disorder increases the risk of developing bipolar disorders in adulthood. Disruptive disorder in childhood or adolescence as well as family histories of BPD emerged as significant risk factors that differentiated between the future development of BPD and MDD. Adolescents with hypomania spectrum episodes and adolescents with MDD do not differ substantially in health outcomes in adulthood. Both groups are at increased risk for subsequent mental health problems, high consumption of prescription drugs, and high health care use, compared with the control group. The high rates of prescription drugs in many ATC classes found among the former depressed females seem to indicate a series of co-morbid somatic illnesses. Thus, it is important to identify and treat children and adolescents with mood disorders, and carefully follow the continuing course. Characteristics such as disruptive disorders and family history warrant particular attention.

The purpose of this study was to examine the effect of mood lability on anticipation timing performance. The influence of gender and stimulus speed on timing error was also analysed. Spectral analysis was used to quantify frequency of mood change. The within-subjects standard deviation was calculated as a measure of intensity of mood change. Thirty-eight physical education students (18 men; M = 23.8 yrs, SD = 2.1 and 20 women; M = 20.4 yrs, SD = 1.6) participated in this study. Mood changes were measured along the Pleasantness and Energetic dimensions of the Affect Grid. Performance was assessed using the Bassin Anticipation Timer. It was hypothesized that: the fast mood changers would incur greater timing errors than the slow mood changers, men would perform with less error than women, and stimulus speed would have a significant influence on timing error. / Mixed factorial ANOVAs with repeated measures on the last factor were utilized to compare mean timing error scores: constant error, absolute error, variable error, and total error, over two levels of frequency of mood change (fast/slow) and intensity of mood change (high/low) groups, two levels of gender (men/women) and four levels of stimulus speed (5/10/15/25 mph). Alpha was set at the.05 significance level for all statistical comparisons. Results showed that intensity of mood change had a significant influence on anticipation timing performance, frequency of mood change factor did not have a significant effect on timing error, men performed with less variability than women and stimulus speed had a significant influence on anticipation timing. The Profile of Mood States (POMS) results, showed that women scored lower on the negative mood states than men. Total mood disturbance for both men and women showed no significant relationship to the timing error scores.

Mood and cognition, along with numerous other physiological processes, are under circadian regulation. The synthesis and secretion rhythm of the pineal hormone melatonin is under the direct regulation of the central circadian pacemaker and the secretion rhythm of melatonin can be used to assess circadian alterations. In this thesis, it was demonstrated that low levels of endogenous nocturnal melatonin was associated with subsyndromal depression and alterations in sleep architecture. Studies in individuals with endogenous circadian rhythm disorder, with and without comorbid depressive symptoms, revealed that individuals with depressive symptoms had a greater phase delay in melatonin profiles as compared to individuals without depressive symptoms. Furthermore, in the same study, exogenous melatonin administered to induce phase advances significantly improved depression scores and sleep initiation. In addition to endogenous circadian disruption, circadian rhythms can also be disrupted by repeated atypical alterations in environmental time cues. In mammals, light is the strongest environmental cue that can modulate circadian rhythms. Recent studies suggest that circadian response to photic stimuli is preferentially sensitive to short wavelengths in the range of 450-480 nm. Using an animal model it was demonstrated that filtering a 10 nm bandwidth between 470-480 nm from polychromatic white light prevents nocturnal light exposure induced disruptions in melatonin and corticosterone secretion as well as central and peripheral clock gene expression. These findings were further investigated in humans and revealed that filtering short wavelengths below 480 nm attenuates 12 h nocturnal light exposure induced suppression of melatonin secretion, increased cortisol secretion and disrupted peripheral clock gene expression. Furthermore, attenuation of these changes was associated with improvements in mood, alertness and vigilance at a time close to the endogenous circadian wake drive. However, filtering short wavelengths below 460 nm or reducing the optical transmission by up to 30% below 480 nm did not attenuate the disruptive effects of nocturnal light exposure on physiological and behavioural variables. Overall, the results presented in this thesis support the role of circadian dysfunction in neuropsychometric impairment and presents evidence supporting spectral modulation as a promising approach to attenuate light-mediated chronodisruption.

The focus of this thesis is to explore the impact of positive affective state and mood salience on intertemporal decision making. We found that positive affect significantly influence intertemporal preference. We also found that when current mood becomes salient to the decision maker, the direction of preference changes. Specifically, we hypothesized and found that individuals with positive mood are more likely to choose the later larger (long term) rewards than the individuals with a neutral mood. We discuss three factors that could explain choice behaviour in such situations. These factors are the willingness to maintain positive mood, temporal orientation and risk perception, and increase in the level of dopamine in brain. Moreover, our results indicate that when current positive mood is salient, individuals become more concerned about their affective state, and are more likely to engage in affect regulation, and as a result, more likely to prefer the sooner smaller (immediate) rewards. These findings suggest that experiencing positive affect would increase patience and self-control. However, this is the case when the level of mood salience is not high. When individuals’ attention is directed to their emotional states, they tend to choose sooner smaller rewards that could assist them in keeping their good mood and avoiding negative feelings.

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A number of studies have suggested that the right cerebral hemisphere declines, functionally, more rapidly, and to a greater degree, than does the left hemisphere, as the human adult ages. Furthermore, research has suggested a possible link between age by gender-related changes in cognitive function and changes in mood and levels of social engagement. Importantly, a literature search identified that no previous study has employed a divided visual field experimental technique, where emotionally valenced verbal stimuli have been presented, in order to test whether selective impairment of right cerebral hemisphere functioning is associated with normal adult ageing. Nor has any study investigated associations between age, gender, levels of social engagement, mood, and performances in the perception of both emotionally valenced verbal stimuli and facial affect. The present study investigated whether a selective impairment of right cerebral hemispheric cognitive functioning, in relation to emotion perception, is associated with normal adult ageing. In addition, the present study explored whether any relationships exist between an age-related and/or age by gender-related right cerebral hemispheric cognitive impairment, problems with mood, and deficits in social engagement. Two divided visual field experiments were conducted: one divided visual field experiment employed verbal stimuli, and the other, facial image stimuli. These two experiments attempted to assess changes, with adult ageing, in hemispheric specialisation for the perception of emotion by tachistoscopically presenting valenced (positive, neutral, or negative) verbal and facial image stimuli, within a divided visual field experimental paradigm. The studies were conducted across two groups (an old group and a young group of subjects), whilst controlling for gender, handedness and verbal ability of subjects. The dependent variables in these two experiments were the subjects' reaction times to the stimuli, accuracy of identification of the emotional valence of the stimuli, and response biases to these stimuli. The data derived from the verbal divided visual field and facial image divided visual field experiments did not indicate any changes in relation to the laterality of emotion perception as the adult human being ages. Importantly, though, the results from both of the aforementioned experiments revealed that the older group of subjects responded more slowly and less accurately to the emotionally valued stimuli than did the younger group of subjects, suggesting that deficits in emotion perception occur with adult ageing. In addition, the results suggested age by gender-specific relationships, whereby an overall lowering in cognitive ability for older men was associated with a lowering in ability to accurately perceive the emotional valence of the stimuli. For older women it was found that a lowering in cognitive ability largely mediated by the left cerebral hemisphere was associated with a lowering in ability to accurately perceive the emotional valence of the stimuli, whilst cognitive ability for young persons was not associated with this variable. The data also suggested that for the young women, a heightened level of cognitive ability largely mediated by the left cerebral hemisphere was associated with a lowering in satisfaction with their level of social interaction, whereas a heightened level of cognitive ability largely mediated by the right cerebral hemisphere was associated with a heightened level of mood disturbance. Gender-specific relationships were also found, whereby for both the older and younger women, a heightened level of mood disturbance was associated with a lowering in satisfaction with their level of social interaction, whilst for both the older and younger men these variables had no relationship. Furthermore, an age by gender-specific relationship was revealed, whereby for the older men, a heightened level of satisfaction with their level of social interaction was associated with a heightened level of social engagement, whilst for the young men, and both the young and older women, these variables had no relationship.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. Inst., 2002. / Härtill 6 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 6 uppsatser.