Discuss Bipolar
Blog to discuss being Bipolar
US researchers have found thyroid function is inhibited in bipolar I disorder patients taking maintenance lithium monotherapy, which may exacerbate the illness, particularly in the depressive pole.
It is known that lithium can impair thyroid function, but the potential relationship between the induced thyroid changes and prospective mood changes has not been extensively studied.
To investigate, Mark Frye (Mayo Clinic, Rochester, Minnesota) and co-authors pooled data from two 18-month maintenance studies of lamotrigine and lithium monotherapy. The post hoc analysis included 109 bipolar I patients with normal thyroid-stimulating hormone (TSH) levels at baseline who received lamotrigine (n=55), lithium (n=32), or placebo (n=22) monotherapy for a mean period of 52 weeks.
The researchers found that by week 52, patients treated with lithium had a statistically significant increase in mean TSH levels from baseline (+1.0 µIU/ml) compared with those treated with lamotrigine (-0.2 µIU/ml) or placebo (+0.1 µIU/ml). Additionally, three patients taking lithium developed above normal TSH levels by week 52 (8.4, 6.5, and 7.8 µIU/ml).
“This finding is consistent with the possibility that llithium-associated inhibition of thyroid function might have contributed to the development of depressive symptoms. If so, then the results suggest that reduction in thyroid function can exacerbate bipolar symptoms even in euthyroid patients,” write Frye et al in the journal Acta Psychiatrica Scandinavica.
Furthermore, lithium-treated patients who required an intervention for a depressive episode had significantly higher TSH levels compared with those who did not need intervention (4.4 vs 2.4 µIU/ml). This significant difference was not seen in other groups or in the manic episode.
The authors suggest that this may indicate that bipolar depressive symptoms may be influenced by reductions in thyroid function that are captured as values within the normal range (0.3??”5.0 µIU/ml).
However, the team cautions that TSH at screening is not as accurate an assessment as levels at time of randomization due to the possibility of TSH changes prior to analysis.
“Studies prospectively designed to assess thyroid function and its association with subsyndromal and syndromal mood symptoms in patients receiving maintenance therapy for bipolar disorder should be considered,” they conclude.
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a part of Springer Science+Business Media. © Current Medicine Group Ltd; 2009
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People with bipolar disorder commonly exhibit functional impairment despite being euthymic and clinically “in remission”, say the authors of a new study.
The team believes that a number of clinical factors can predict functional impairment in bipolar disorder, such as previous mixed mood episodes, current subclinical depression, previous hospitalization, and older age.
Eduard Vieta (University of Barcelona, Spain) and coworkers studied 71 patients with a diagnosis of bipolar disorder but currently defined as euthymic (scoring ?8 on the 17-item Hamilton Depression Rating Scale) and 61 healthy controls.
All subjects underwent a battery of tests including the Functioning Assessment Short Test (FAST), which assesses autonomy, occupational functioning, cognition, relationships, financial issues, and leisure time.
In all, 60% of the bipolar patients were considered to be functionally impaired (based on a FAST score >11) compared with just 13.1% of controls. In multivariate analysis, four variables ??” older age, depressive symptoms, previous mixed episodes, and previous hospitalizations ??” were significantly associated with impaired functioning.
Together, these four factors accounted for 44% of the variance in global functioning, Vieta’s team calculated.
Writing in Bipolar Disorders journal, the researchers say their study supports the hypothesis that more severe forms of bipolar disorder have long-term adverse consequences, notably cognitive and functional impairment, that are apparent in-between acute episodes.
“Psychosocial interventions in combination with pharmacotherapy should be considered to treat residual depressive symptoms and enhance the level of functioning,” write Vieta et al.
“In addition, low rates of functional recovery as shown here underscore the importance of including specific functioning measures as well as symptomatic assessments in the comprehensive evaluation of bipolar disorder.”
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a part of Springer Science+Business Media. © Current Medicine Group Ltd; 2009