Affective disorders in a stress-vulnerability perspective : a clinical, biological and psycho-social study

<p>Affective illness is a common, recurrent and often severe illness, which causes severe suffering to the patients and their families, friends and co-workers. Furthermore the costs for society are substantial. The aims of this thesis were to study affective disorder from a stress-vulnerability perspective, investigating how genetic, biological and psychosocial factors influence the aetiology and the course and outcome of the illness.</p><p>First, we explored the genetic influence on the aetiology of affective illness, comparing monozygotic and dizygotic twins. The results showed that genetic factors play a major role in the aetiology of affective illness and that heritable factors appear to be equally important in affective illness as ascertained in clinical and epidemiological samples.</p><p>The aim of the second study was to investigate the presence of cognitive impairment in a group of patients with affective illness. The findings indicate that a subgroup of patients are defined by more episodes of hospitalization and cognitive impairment even when euthymic.</p><p>The third study analyzed if the age of onset in affective illness relates to family history, early parental separation and life events. A five-year lower onset was found in bipolar patients with a positive family history of affective illness, compared to those without a family history. Furthermore, bipolar patients with heredity, had less life events at onset. Bipolar patients with preceding life events had a 4.8-year higher onset, compared to those without life events. For bipolar as well as unipolar patients, life stressors more frequently preceded the first episode than the subsequent episodes.</p><p>In the fourth paper, the purpose was to investigate whether the stabilizing effect of lithium is dependent on short-term availability of serotonin. Despite a 80 % reduction of tryptophan (precursor to serotonin), no clinically relevant mood changes were observed, suggesting that a transient reduction in serotonergic function does not seem to affect mood in patients, stabilized on lithium treatment.</p><p>The influence of social support on bipolar illness was investigated in the fifth study. Patients without full interepisode recovery and patients with a higher risk of relapse during a one-year follow-up were found to perceive a significantly lower level of social support.</p><p>Finally, in the sixth study, the influence of personality on the course and outcome of bipolar I illness was explored. Patients in partial interepisode recovery and with a higher risk of hospitalization during a three-year follow-up had a significantly higher level of harm avoidance, a higher level of interpersonal problems, and a lower level of sense of coherence.</p><p>In summary, the results of this thesis suggest that: (1) genetic factors play a major aetiological role in affective illness and influence the age of onset in bipolar illness; (2) life events are of greater importance early in the course of affective illness; and (3) bipolar patients with cognitive impairment, a low level of perceived social support, and abnormal levels of certain personality characteristics are at higher risk of poor outcome.</p><h3>List of scientific papers</h3><p>I. Kendler KS, Pedersen N, Johnson L, Neale MC, Mathe AA (1993). A pilot Swedish twin study of affective illness, including hospital- and population-ascertained subsamples. Arch Gen Psychiatry. 50(9): 699-700. <br><a href="https://pubmed.ncbi.nlm.nih.gov/8357295">https://pubmed.ncbi.nlm.nih.gov/8357295</a><br><br></p><p>II. Tham A, Engelbrektson K, Mathe AA, Johnson L, Olsson E, Aberg-Wistedt A (1997). Impaired neuropsychological performance in euthymic patients with recurring mood disorders. J Clin Psychiatry. 58(1): 26-9. <br><a href="https://pubmed.ncbi.nlm.nih.gov/9055834">https://pubmed.ncbi.nlm.nih.gov/9055834</a><br><br></p><p>III. Johnson L, Andersson-Lundman G, Aberg-Wistedt A, Mathe AA (2000). Age of onset in affective disorder: its correlation with hereditary and psychosocial factors. J Affect Disord. 59(2): 139-48. <br><a href="https://pubmed.ncbi.nlm.nih.gov/10837882">https://pubmed.ncbi.nlm.nih.gov/10837882</a><br><br></p><p>IV. Johnson L, El-Khoury A, Aberg-Wistedt A, Stain-Malmgren R, Mathe AA (2001). Tryptophan depletion in lithium-stabilized patients with affective disorder. Int J Neuropsychopharmacol. 4(4): 329-36. <br><a href="https://pubmed.ncbi.nlm.nih.gov/11806858">https://pubmed.ncbi.nlm.nih.gov/11806858</a><br><br></p><p>V. Johnson L, Lundstrom O, Aberg-Wistedt A, Mathe AA (2002). Social support in bipolar disorder: its relevance to remission and relapse. [Submitted]</p><p>VI. Johnson L, Carlsson AM, Aberg-Wistedt A, Mathe AA (2002). Personality traits in bipolar I disorder: its relevance to recovery and relapse. [Manuscript]</p>