Bipolar Disorder: Parikh S

Yatham LN, Kennedy SH, O'Donovan C, Parikh S, MacQueen G, McIntyre R, Sharma V, Silverstone P, Alda M, Baruch P, Beaulieu S, Daigneault A, Milev R, Young LT, Ravindran A, Schaffer A, Connolly M, Gorman CP, Anonymous00076. · Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada. · Bipolar Disord. · Pubmed #15952957 No free full text.

Abstract: Since the previous publication of Canadian Network for Mood and Anxiety Treatments (CANMAT) guidelines in 1997, there has been a substantial increase in evidence-based treatment options for bipolar disorder. The present guidelines review the new evidence and use criteria to rate strength of evidence and incorporate effectiveness, safety, and tolerability data to determine global clinical recommendations for treatment of various phases of bipolar disorder. The guidelines suggest that although pharmacotherapy forms the cornerstone of management, utilization of adjunctive psychosocial treatments and incorporation of chronic disease management model involving a healthcare team are required in providing optimal management for patients with bipolar disorder. Lithium, valproate and several atypical antipsychotics are first-line treatments for acute mania. Bipolar depression and mixed states are frequently associated with suicidal acts; therefore assessment for suicide should always be an integral part of managing any bipolar patient. Lithium, lamotrigine or various combinations of antidepressant and mood-stabilizing agents are first-line treatments for bipolar depression. First-line options in the maintenance treatment of bipolar disorder are lithium, lamotrigine, valproate and olanzapine. Historical and symptom profiles help with treatment selection. With the growing recognition of bipolar II disorders, it is anticipated that a larger body of evidence will become available to guide treatment of this common and disabling condition. These guidelines also discuss issues related to bipolar disorder in women and those with comorbidity and include a section on safety and monitoring.

McIntyre RS, Mancini DA, Parikh S, Kennedy SH. · Bipolar Clinic, Centre for Addiction and Mental Health, 250 College Street, Toronto, ON M5T 1R8. · Can J Psychiatry. · Pubmed #11387787 No free full text.

Abstract: OBJECTIVE: To review lithium's utility in the treatment of mood disorders. METHOD: We reviewed the safety, tolerability, teratogenicity, optimal dosing regimens, and mortality-lowering effects of lithium. Clinical relevance and scientific rigour determined which articles we selected for review. RESULTS: Lithium is the paradigmatic treatment for bipolar disorder (BD). In treating BD, optimal maintenance plasma levels may be approximately 0.75 to 0.85 mEq/L. Although nephrogenic diabetes insipidus is not uncommon, irreversible renal failure due to lithium appears to be a rare, idiosyncratic event. Lithium-induced cardiovascular teratology appears to be less common than previously thought. Optimal lithium dosing may be once daily, this agent appears to bestow a robust suicide-lowering effect, and emerging data hint at neurotrophic and neuroprotective effects. CONCLUSION: Lithium remains an effective and integral agent in the treatment of BD. Its ability to lower suicide rates in persons with BD warrants clinical attention.

Krüger S, Alda M, Young LT, Goldapple K, Parikh S, Mayberg HS. · Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada. · Am J Psychiatry. · Pubmed #16449479 links to  free full text

Abstract: OBJECTIVE: The authors previously identified depression-specific differences in brain responses to an emotional challenge in patients with bipolar and unipolar mood disorder. In this study, potential markers of bipolar risk and resilience were examined in a new cohort of lithium-responsive bipolar patients and their healthy siblings. METHOD: Changes in regional cerebral blood flow (rCBF) were measured with [(15)O]water positron emission tomography after induction of transient sadness in nine euthymic lithium responders and nine healthy siblings. The patterns of change in these groups were compared, and then they were contrasted with previous findings on bipolar responders to valproate. RESULTS: Common to all three groups with induced sadness were rCBF increases in the dorsal/rostral anterior cingulate and anterior insula and decreases in the orbitofrontal and inferior temporal cortices. Distinguishing the groups were decreases in the medial frontal cortex in the patients but an increase in this region in the siblings. DISCUSSION: Common changes with emotional challenge were identified in bipolar patients and their healthy siblings. These were not seen previously in healthy subjects without a family history of mood disorder, suggesting a potential marker of bipolar risk. The siblings' unique increases in the medial frontal cortex appear to identify a compensatory response in this at-risk group, as this pattern was not seen previously in healthy subjects without depression risk factors. This differential change pattern in patients and their siblings highlights the role of the anterior cingulate and medial frontal regions in mediating resiliency and vulnerability in bipolar disorder families.

Ni X, Trakalo JM, Mundo E, Lee L, Parikh S, Kennedy JL. · Neurogenetics Section, Centre for Addiction and Mental Health, Toronto, Canada. · Neuromolecular Med. · Pubmed #12622403 No free full text.

Abstract: OBJECTIVES: The serotonin 2A receptor gene (5-HT2A) is of great interest for research in neuropsychiatric disorders based on the observation that various neuroleptic agents and antidepressants bind with relatively high affinity at 5-HT2A receptors, and the fact that the receptor density in platelets tends to increase in depression. To test for the presence of association between 5-HT2A and bipolar disorder (BP), we studied a large number of triad families having probands affected with DSM-IV bipolar I (BPI), bipolar II (BPII) or schizoaffective disorder, bipolar type. METHODS: Two polymorphisms of 5-HT2A, 102T/C, and His452Tyr were analyzed in the 274 bipolar triad families. Both the transmission disequilibrium test (TDT) and haplotype TDT were performed on the genotype data. We also calculated the maternal transmission and paternal transmission for each allele and compared the mean ages of onset across probands grouped by genotype at each of the two markers. RESULTS: No significant transmission disequilibrium between the alleles of 5-HT2A and BP was found. Separate studies of the sub-phenotypes also failed to demonstrate significant association. However, we found a trend towards transmission disequilibrium with the haplotype 102C.His452 (p = 0.0504). This trend may become more significant with a larger sample size. SIGNIFICANCE: At present, results of this study suggest that the 5-HT2A is unlikely to play a major role in the genetic susceptibility to BP. Future studies will be directed towards increasing sample size, focusing on subtypes of BP or biochemical measures as phenotypes, and investigating other polymorphisms of 5-HT2A to provide more information at the DNA level.

Ni X, Trakalo JM, Mundo E, Macciardi FM, Parikh S, Lee L, Kennedy JL. · Neurogenetics Section, Centre for Addiction and Mental Health, Toronto, Canada. · Biol Psychiatry. · Pubmed #12488059 No free full text.

Abstract: BACKGROUND: Based on the dopamine hypothesis, the dopamine D1 receptor gene (DRD1) is considered to be a good candidate gene for bipolar disorder (BP). METHODS: In our study, three polymorphisms of the DRD1 gene, -800T/C, -48A/G, and 1403T/C, were analyzed in 286 BP trios. Both the transmission disequilibrium test (TDT) and haplotype TDT were performed on the genotype data to test for the presence of linkage disequilibrium between DRD1 and bipolar disorder. With the extended transmission disequilibrium test (ETDT), we also calculated the maternal transmission and paternal transmission for each allele. RESULTS: Although no association was found for each individual polymorphism, there is a significant association between DRD1 and BP for haplotype TDT analysis (chi(2) = 16.068, df = 3, p =.0011). CONCLUSIONS: These results indicate that DRD1 may play a role in the etiology of bipolar disorder.