title: Serum homocysteine levels and cognitive functioning in euthymic bipolar patients.
abstract: BACKGROUND
  Studies have found elevated plasma homocysteine (Hcy) levels in bipolar disorder (BD). We investigated serum Hcy levels in euthymic BD patients, and its relationship with cognitive and psychosocial functioning.
  
  
  METHODS
  Sixty-five BD type I euthymic patients and 49 healthy controls were assessed using a neuropsychological test battery. Hcy levels were measured using an HPLC method with fluorescence detection.
  
  
  RESULTS
  The mean Hcy levels were 1.37 mg/L for BD patients and 1.30 mg/L for healthy controls (P=0.342), male patients showing higher Hcy levels as compared to females (P=0.009). Older patients, those with later illness onset, and patients taking more medications showed higher Hcy levels, but no significant correlation was found with psychosocial functioning. Patients with "elevated" Hcy levels performed significantly worse on all neurocognitive tests, and in patients we found significant associations between Hcy levels and number of perseverations on the SCT (r=0.248, P=0.047), and number of moves on the ToH (r=0.265, P=0.033); however, a linear regression model revealed that Hcy was not a significant predictor of neurocognitive test performance.
  
  
  CONCLUSIONS
  Our findings suggest that increased homocysteinemia may play a role in the pathophysiology of neurocognitive deficits in BD, with a higher impact among older patients, or who had a delayed onset of illness.
authors.affiliation: University of Extremadura, Badajoz, Spain.
authors.forename: Vasco Videira
authors.initials: VV
authors.lastname: Dias
authors.forename: Sofia
authors.initials: S
authors.lastname: Brissos
authors.forename: Carlos
authors.initials: C
authors.lastname: Cardoso
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Andreazza
authors.forename: Flávio
authors.initials: F
authors.lastname: Kapczinski
mesh_terms: D000328:Adult; D000367:Age Factors; D001714:Bipolar Disorder / Q000097:blood* / Q000453:epidemiology* / Q000523:psychology; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology*; D003710:Demography; D039721:Diagnostic and Statistical Manual of Mental Disorders; D019263:Dysthymic Disorder / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D005260:Female; D005492:Folic Acid / Q000097:blood; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D012720:Severity of Illness Index; D012737:Sex Factors; D014805:Vitamin B 12 / Q000097:blood
chemical_list: D006710:Homocysteine; D005492:Folic Acid; D014805:Vitamin B 12