BackgroundManic and depressive mood states in bipolar disorder (BD) may emerge from the non-linear relations between constantly changing mood symptoms exhibited as a complex dynamic system. Dynamic... Show moreBackgroundManic and depressive mood states in bipolar disorder (BD) may emerge from the non-linear relations between constantly changing mood symptoms exhibited as a complex dynamic system. Dynamic Time Warp (DTW) is an algorithm that may capture symptom interactions from panel data with sparse observations over time.MethodsThe Young Mania Rating Scale and Quick Inventory of Depressive Symptomatology were repeatedly assessed in 141 individuals with BD, with on average 5.5 assessments per subject every 3–6 months. Dynamic Time Warp calculated the distance between each of the 27 × 27 pairs of standardized symptom scores. The changing profile of standardized symptom scores of BD participants was analyzed in individual subjects, yielding symptom dimensions in aggregated group-level analyses. Using an asymmetric time-window, symptom changes that preceded other symptom changes (i.e., Granger causality) yielded a directed network.ResultsThe mean age of the BD participants was 40.1 (SD 13.5) years old, and 60% were female participants. Idiographic symptom networks were highly variable between subjects. Yet, nomothetic analyses showed five symptom dimensions: core (hypo)mania (6 items), dysphoric mania (5 items), lethargy (7 items), somatic/suicidality (6 items), and sleep (3 items). Symptoms of the “Lethargy” dimension showed the highest out-strength, and its changes preceded those of “somatic/suicidality,” while changes in “core (hypo)mania” preceded those of “dysphoric mania.”ConclusionDynamic Time Warp may help to capture meaningful BD symptom interactions from panel data with sparse observations. It may increase insight into the temporal dynamics of symptoms, as those with high out-strength (rather than high in-strength) could be promising targets for intervention. Show less
Koenders, M.A.; Mesbah, R.; Spijker, A.T.; Boere, E.; de Leeuw, M.; van Hemert, A.M.; Giltay, E.J. 2021
Background: Bipolar disorder (BD) is characterized by the alternating occurrence of (hypo)manic and depressive episodes. The aim of the current study was to determine whether personality traits... Show moreBackground: Bipolar disorder (BD) is characterized by the alternating occurrence of (hypo)manic and depressive episodes. The aim of the current study was to determine whether personality traits independently predicted the subsequent development of (hypo)manic episodes within a group of patients who were initially diagnosed with depressive and anxiety disorders.Methods: The Netherlands Study of Depression and Anxiety is a cohort study with measurements taken at baseline and at 2-, 4-, 6-, and 9-year follow-up. Development of a (hypo)manic episode during follow-up was assessed with the Composite International Diagnostic Interview and (hypo)manic symptoms were evaluated with the Mood Disorder Questionnaire. The Big Five personality traits were the independent variables in multivariable Cox regression analyses.Results: There were 31 incident cases of (hypo)manic episodes (n = 1888, mean age 42.5 years, 68.3% women), and 233 incident cases of (hypo)manic symptoms (n = 1319, mean age 43.1, 71.9% women). In multivariable analyses, low agreeableness was independently associated with an increased risk of developing a (hypo) manic episode, with a hazard ratio (HR) of 0.54 (p = 0.002, 95% CI [0.37, 0.78]). This finding was consistent with the development of (hypo)manic symptoms (HR 0.77, p = 0.001, 95% CI [0.66, 0.89]).Limitations: The 2-year lag-time analysis reduced the number of participants at risk of a (hypo)manic episode.Conclusions: We conclude that low agreeableness is a personality-related risk factor for incident (hypo)mania among subjects initially suffering from depressive and anxiety disorders. Increased attention to personality deviances could help to recognize BD at an early stage. Show less
BackgroundBipolar disorder (BD) is characterized by the alternating occurrence of (hypo)manic and depressive episodes. The aim of the current study was to determine whether personality traits... Show moreBackgroundBipolar disorder (BD) is characterized by the alternating occurrence of (hypo)manic and depressive episodes. The aim of the current study was to determine whether personality traits independently predicted the subsequent development of (hypo)manic episodes within a group of patients who were initially diagnosed with depressive and anxiety disorders.MethodsThe Netherlands Study of Depression and Anxiety is a cohort study with measurements taken at baseline and at 2-, 4-, 6-, and 9-year follow-up. Development of a (hypo)manic episode during follow-up was assessed with the Composite International Diagnostic Interview and (hypo)manic symptoms were evaluated with the Mood Disorder Questionnaire. The Big Five personality traits were the independent variables in multivariable Cox regression analyses.ResultsThere were 31 incident cases of (hypo)manic episodes (n = 1888, mean age 42.5 years, 68.3% women), and 233 incident cases of (hypo)manic symptoms (n = 1319, mean age 43.1, 71.9% women). In multivariable analyses, low agreeableness was independently associated with an increased risk of developing a (hypo)manic episode, with a hazard ratio (HR) of 0.54 (p = 0.002, 95% CI [0.37, 0.78]). This finding was consistent with the development of (hypo)manic symptoms (HR 0.77, p = 0.001, 95% CI [0.66, 0.89]).LimitationsThe 2-year lag-time analysis reduced the number of participants at risk of a (hypo)manic episode.ConclusionsWe conclude that low agreeableness is a personality-related risk factor for incident (hypo)mania among subjects initially suffering from depressive and anxiety disorders. Increased attention to personality deviances could help to recognize BD at an early stage. Show less
BACKGROUND\nSchizophrenia is associated with lower intelligence and poor educational performance relative to the general population. This is, to a lesser degree, also found in first-degree... Show moreBACKGROUND\nSchizophrenia is associated with lower intelligence and poor educational performance relative to the general population. This is, to a lesser degree, also found in first-degree relatives of schizophrenia patients. It is unclear whether bipolar disorder I (BD-I) patients and their relatives have similar lower intellectual and educational performance as that observed in schizophrenia.\nMETHOD\nThis cross-sectional study investigated intelligence and educational performance in two outpatient samples [494 BD-I patients, 952 schizophrenia spectrum (SCZ) patients], 2231 relatives of BD-I and SCZ patients, 1104 healthy controls and 100 control siblings. Mixed-effects and regression models were used to compare groups on intelligence and educational performance.\nRESULTS\nBD-I patients were more likely to have completed the highest level of education (odds ratio 1.88, 95% confidence interval 1.66-2.70) despite having a lower IQ compared to controls (β = -9.09, s.e. = 1.27, p < 0.001). In contrast, SCZ patients showed both a lower IQ (β = -15.31, s.e. = 0.86, p < 0.001) and lower educational levels compared to controls. Siblings of both patient groups had significantly lower IQ than control siblings, but did not differ on educational performance. IQ scores did not differ between BD-I parents and SCZ parents, but BD-I parents had completed higher educational levels.\nCONCLUSIONS\nAlthough BD-I patients had a lower IQ than controls, they were more likely to have completed the highest level of education. This contrasts with SCZ patients, who showed both intellectual and educational deficits compared to healthy controls. Since relatives of BD-I patients did not demonstrate superior educational performance, our data suggest that high educational performance may be a distinctive feature of bipolar disorder patients. Show less
