Impact of sunlight on the age of onset of bipolar disorder.

OBJECTIVE: Although bipolar disorder has high heritability, the onset occurs during several decades of life, suggesting that social and environmental factors may have considerable influence on disease onset. This study examined the association between the age of onset and sunlight at the location of onset. METHOD: Data were obtained from 2414 patients with a diagnosis of bipolar I disorder, according to DSM-IV criteria. Data were collected at 24 sites in 13 countries spanning latitudes 6.3 to 63.4 degrees from the equator, including data from both hemispheres. The age of onset and location of onset were obtained retrospectively, from patient records and/or direct interviews. Solar insolation data, or the amount of electromagnetic energy striking the surface of the earth, were obtained from the NASA Surface Meteorology and Solar Energy (SSE) database for each location of onset. RESULTS: The larger the maximum monthly increase in solar insolation at the location of onset, the younger the age of onset (coefficient= -4.724, 95% CI: -8.124 to -1.323, p=0.006), controlling for each country's median age. The maximum monthly increase in solar insolation occurred in springtime. No relationships were found between the age of onset and latitude, yearly total solar insolation, and the maximum monthly decrease in solar insolation. The largest maximum monthly increases in solar insolation occurred in diverse environments, including Norway, arid areas in California, and Chile. CONCLUSION: The large maximum monthly increase in sunlight in springtime may have an important influence on the onset of bipolar disorder.

Brief depressive symptoms in patients with bipolar disorder: analysis of long-term self-reported data.

OBJECTIVE: Most patients with bipolar disorder experience depressive symptoms outside of an episode of depression as defined by DSM-IV criteria. This study explores the frequency of brief depressive episodes, lasting 1 to 4 days, using daily self-reported mood ratings. METHOD: Mood ratings were obtained from 448 patients (281 bipolar I, 167 bipolar II) using ChronoRecord software (91,786 total days). Episodes of depression and days of depression outside of episodes were determined. The intensity of depressive symptoms (mild versus moderate to severe) was compared. RESULTS: Using the DSM-IV length criteria, 61% of all depressive days occurred outside of a depressed episode. Decreasing the minimum length criterion to 2 days, both the number of patients experiencing a depressed episode (128 to 317) and the mean percent of days spent in a depressed episode by each patient (7.9% to 17.8.%) increased by about 2½ times, and 34.3% of depressed days remained outside of an episode. Depending on the episode length, the proportion of days within an episode with severe symptoms varied from 1/3 to 1/4 for episodes lasting from 14 to 2 days, and 1/4 for single-day episodes. There was no significant difference in the frequency of brief depressive episodes between bipolar I and II disorders. For all episode lengths, patients taking antidepressants spent 4% more days within an episode and 6% more days with depressive symptoms outside of an episode than those not taking antidepressants. CONCLUSION: Brief depressive episodes lasting 1 to 4 days occur frequently in bipolar disorder and do not distinguish between bipolar I and II disorders. Symptoms of moderate to severe intensity occur on 1/4 to 1/3 of the days in brief depressive episodes. This study did not address brief depression in those without bipolar disorder. Patients taking antidepressants experienced more brief depressive episodes. Controlled trials are needed to assess the impact of antidepressants on subsyndromal depressive symptoms.

Decreasing the minimum length criterion for an episode of hypomania: evaluation using self-reported data from patients with bipolar disorder.

Brief hypomania lasting less than 4 days may impair functioning and help to detect bipolarity. This study analyzed brief hypomania that occurred in patients with bipolar disorder who were diagnosed according to the DSM-IV criteria. Daily self-reported mood ratings were obtained from 393 patients (247 bipolar I and 146 bipolar II) for 6 months (75,284 days of data, mean 191.6 days). Episodes of hypomania were calculated using a 4, 3, 2, and single day length criterion. Brief hypomania occurred frequently. With a decrease in the minimum criterion from 4 days to 2 days, there were almost twice as many patients with an episode of hypomania (102 vs. 190), and more than twice as many episodes (305 vs. 863). Single days of hypomania were experienced by 271 (69%) of the sample. With a 2-day episode length, 33% of all hypomania remained outside of an episode. There was no significant difference in the percent of hypomanic days outside of an episode between patients with bipolar I and II disorders. There were no significant differences in the demographic characteristics of patients who met the 4-day minimum as compared with those who only experienced episodes of hypomania using a shortened length criterion. Decreasing the minimum length criterion for an episode of hypomania will cause a large increase in the number of patients who experience an episode and in the aggregate number of episodes, but will not distinguish subgroups within a sample who meet the DSM-IV criteria for bipolar disorder. Frequency may be an important dimensional aspect of brief hypomania. Clinicians should regularly probe for brief hypomania.

Self-reported data from patients with bipolar disorder: frequency of brief depression.

OBJECTIVE: Patients with bipolar disorder often report depressive symptoms that do not meet the DSM-IV criteria for an episode. Using daily self-reported mood ratings, we studied how changing the length requirement to that typical of recurrent brief depression (2-4 days) would impact the number of depressed episodes. METHOD: 203 patients (135 bipolar I and 68 bipolar II by DSM-IV criteria) recorded mood daily using ChronoRecord software on a home computer (30,348 total days; mean 150 days). Episodes of depression and days of depression outside of episodes were determined. Symptom intensity (mild versus moderate or severe) was investigated within and outside of depressive episodes. RESULTS: Decreasing the minimum duration criterion for an episode of depression to 2 days increased the number of patients with a depressed episode two and a half times (52 to 131), and quadrupled both the number of depressed episodes per patient (0.62 to 2.88) and the number of depressed episodes for all patients (125 to 584). With a 2-day episode length, 34% of days of depression remained outside an episode. The ratio of days with severe symptoms within episodes remained consistent (about 25%) in spite of decreasing the episode length to 2 days. Considering only days with severe symptoms, about 25% remained outside of episodes even with a 2-day length. None of the results distinguished bipolar I from bipolar II disorder. LIMITATIONS: Self-reported data, computer access required, relatively short study length, no control group. CONCLUSION: Brief depressive episodes and single days of depression outside of episodes occur frequently in both bipolar I and bipolar II disorder. Moderate or severe symptoms occur during brief episodes at a ratio similar to that for episodes that meet the DSM-IV criteria.

Self-reported data from patients with bipolar disorder: impact on minimum episode length for hypomania.

OBJECTIVE: Some investigators have suggested decreasing the minimum hypomania episode length criterion from 4 days, as in the DSM-IV, to 2 days. Using daily self-reported mood ratings, we studied the impact of changing the length requirement on the number of hypomanic episodes in patients with bipolar disorder. METHOD: 203 patients (135 bipolar I and 68 bipolar II by DSM-IV criteria) recorded mood daily using ChronoRecord software (30,348 total days, mean 150 days). Episodes of hypomania and days of hypomania outside of episodes were determined. RESULTS: Decreasing the minimum duration criterion for an episode of hypomania from 4 to 2 days doubled the mean percent of days in a hypomanic episode for each patient (4% to 8%), doubled the number of patients with a hypomanic episode (44 to 96) and increased the number of hypomanic episodes for all patients about three-fold (129 to 404). With a minimum episode length of 4 days, bipolar I patients were more likely to report hypomania outside episodes than bipolar II patients (p=0.010), but with a length of 2 or 3 days there was no significant difference in the distribution of hypomania outside of episodes by diagnosis. With a 2-day length, about one-third (36%) of hypomania remained outside of an episode. LIMITATIONS: Self-reported data, computer access, relatively short length, fewer bipolar II than bipolar I patients. CONCLUSION: As the minimum length for an episode of hypomania decreases, there was a large increase in both the number of episodes and number of patients with episodes. One-day hypomania outside of episodes occurs frequently in both bipolar I and bipolar II disorder.

Different patterns of manic/hypomanic symptoms in depression: A pilot modification of the hypomania checklist-32 to assess mixed depression.

BACKGROUND: There are no self-report scales that assess manic/hypomanic symptoms in patients with depression. The aim of this study was to explore the use of a modified screening instrument for bipolar disorder to assess current manic/hypomanic symptoms in patients with a depressive episode. METHODS: The study sample consisted of 188 patients with Structured Clinical Interview for DSM-IV-TR disorders (SCID) confirmed bipolar or major depressive disorder. We modified the Hypomania Checklist-32 (mHCL-32) to assess current instead of lifetime symptoms. An Exploratory Factor Analysis (EFA) was conducted to identify clusters of mHCL-32 items that were endorsed concurrently. A Latent Class Analysis (LCA) was carried out to identify groups of patients with similar mHCL-32 item endorsement patterns. RESULTS: The EFA identified 3 factors: factor #1 ("elation-disinhibition-increased goal directed activity"), factor #2 ("risk-taking-impulsivity-substance use") and factor #3 (distractibility-irritability). The LCA yielded 3 classes (2 showing manic/hypomanic features). While class #1 patients endorsed more items related to disinhibition and racing thoughts, class #2 patients recognized more items associated with irritability and substance use. LIMITATIONS: Lack of an adequate gold standard measure of mixed depression to compare to, the cross-sectional design and the lack of a validation sample. CONCLUSIONS: The mHCL-32 scale allowed a comprehensive and convergent delineation of hypomanic/manic symptoms in depression. Further validation of these findings is needed.

A multinational study to pilot the modified Hypomania Checklist (mHCL) in the assessment of mixed depression.

BACKGROUND: Mixed depression is a common, dimensional phenomenon that is increasingly recognized in unipolar and bipolar disorders. We piloted a modified version of the Hypomania Checklist (mHCL-32) to assess the prevalence and clinical correlates of concurrent manic (hypo) symptoms in depressed patients. METHODS: The mHCL-32, Young Mania Rating Scale (YMRS) and Hamilton Rating Scale for Depression (HAMD-24) were utilized in the assessment of unipolar (UP=61) and bipolar (BP=44) patients with an index major depressive episode confirmed by the Structured Clinical Interview for DSM-IV (SCID). Differential mHLC-32 item endorsement was compared between UP and BP. Correlation analyses assessed the association of symptom dimensions measured by mHCL-32, YMRS and HAMD-24. RESULTS: There was no significant difference between mood groups in the mean mHCL-32 and YMRS scores. Individual mHLC-32 items of increased libido, quarrels, and caffeine intake were endorsed more in BP vs. UP patients. The mHCL-32 active-elevated subscale score was positively correlated with the YMRS in BP patients and negatively correlated with HAMD-24 in UP patients. Conversely, the mHCL-32 irritable-risk taking subscale score was positively correlated with HAMD-24 in BP and with YMRS in UP patients. LIMITATIONS: Small sample size and cross-sectional design. CONCLUSION: Modifying the HCL to screen for (hypo) manic symptoms in major depression may have utility in identifying mixed symptoms in both bipolar vs. unipolar depression. Further research is encouraged to quantify mixed symptoms with standardized assessments.

Relationship among latitude, climate, season and self-reported mood in bipolar disorder.

OBJECTIVE: Many researchers have analyzed seasonal variation in hospital admissions for bipolar disorder with inconsistent results. We investigated if a seasonal pattern was present in daily self-reported daily mood ratings from patients living in five climate zones in the northern and southern hemispheres. We also investigated the influence of latitude and seasonal climate variables on mood. METHOD: 360 patients who were receiving treatment as usual recorded mood daily (59,422 total days of data). Both the percentage of days depressed and hypomanic/manic, and the episodes of depression and mania were determined. The observations were provided by patients from different geographic locations in North and South America, Europe and Australia. These data were analyzed for seasonality by climate zone using both a sinusoidal regression and the Gini index. Additionally, the influence of latitude and climate variables on mood was estimated using generalized linear models for each season and month. RESULTS: No seasonality was found in any climate zone by either method. In spite of vastly different weather, neither latitude nor climate variables were associated with mood by season or month. CONCLUSION: Daily self-reported mood ratings of most patients with bipolar disorder did not show a seasonal pattern. Neither climate nor latitude has a primary influence on the daily mood changes of most patients receiving medication for bipolar disorder.

Refractory depression in a patient with peripheral resistance to thyroid hormone (RTH) and the effect of triiodothyronine treatment.

We here described a 39-year-old woman with a severe chronic mood disorder, refractory to antidepressive therapy who showed a significant improvement after a self-prescription of high doses of liothyronine (T(3)). A modified Refetoff protocol was carried out to study the role of thyroid hormones on her clinical and biochemical responses. Depression severity was assessed by the HAM-D and MADRS Depression Rating Scales. Sequencing of Thyroid Receptors (TR) alpha1 and beta1 genes was done. At the final stage of the study, plasma T3 and free T3 were >800 ng/dl (80-180) and 1409 pg/dl (230-420), respectively. No changes in the cardiovascular parameters, alkaline phosphatase isoenzymes, creatinine kinase, or ferritin were observed. However, an improvement in mood was detected by specific scores (HAM-D 24 to 8; MADRS 40 to 11). No mutations in DNA- and hormone-binding-domains of TRbeta1 and TRalpha1 genes were found in proband, suggesting that the defect could be due to an unknown mutation in either the TR gene or a post receptor abnormality. These results support the existence of a peripheral RTH manifestation as a refractory chronic depression reverted by high doses of T(3). Screening for RTH in refractory chronic depression may provide an alternative treatment for this psychiatric condition.

[High prevalence of thyroid dysfunction among psychiatric inpatients]. / Alta prevalencia de disfunción tiroidea en pacientes psiquiátricos hospitalizados.

BACKGROUND: Thyroid dysfunction is frecuent in psychiatric outpatients and in the general Chilean population but there is no information about the prevalence of thyroid diseases in Chilean psychiatric inpatients. AIM: To retrospectively assess the frequency of thyroidal diseases in psychiatric inpatients. MATERIAL AND METHODS: Clinical charts and thyroid assessment of 241 psychiatric inpatients (147 women, mean age 33+/-16 years) attended in a University Psychiatric Clinic, were reviewed. Psychiatric diagnosis at discharge was made according to DSM IV criteria and endocrine diagnosis was made based on international criteria. RESULTS: Forty nine patients (20.7%) had thyroid abnormalities. Forty four patients had hypothyroidism (18.3%) and five had hyperthyroidism (2.35%). No specific associations were found between gender or psychiatric diagnosis and endocrine abnormalities. CONCLUSIONS: In this sample, the prevalence of thyroid abnormalities was similar to other reports in psychiatric inpatiens and higher than in the general population in Chile.

Alta prevalencia de disfunción tiroidea en pacientes psiquiátricos hospitalizados / High prevalence of thyroid dysfunction among psychiatric inpatients

Background: Thyroid dysfunction is frecuent in psychiatric outpatients and in the general Chilean population but there is no information about the prevalence of thyroid diseases in Chilean psychiatric inpatients. Aim: To retrospectively assess the frequency of thyroidal diseases in psychiatric inpatients. Material and Methods: Clinical charts and thyroid assessment of 241 psychiatric inpatients (147 women, mean age 33±16 years) attended in a University Psychiatric Clinic, were reviewed. Psychiatric diagnosis at discharge was made according to DSM IV criteria and endocrine diagnosis was made based on international criteria. Results: Forty nine patients (20.7%) had thyroid abnormalities. Forty four patients had hypothyroidism (18.3%) and five had hyperthyroidism (2.35%). No specific associations were found between gender or psychiatric diagnosis and endocrine abnormalities. Conclusions: In this sample, the prevalence of thyroid abnormalities was similar to other reports in psychiatric inpatiens and higher than in the general population in Chile.