Cognitive functioning and well-being in euthyroid patients on thyroxine replacement therapy for primary hypothyroidism.
OBJECTIVE
Hypothyroidism is associated with neurocognitive impairment. Sparse data suggest that treatment of hypothyroidism, resulting in a return to euthyroidism, may be associated with only partial recovery of overall neurocognitive functioning. The aim of this study was to assess neurocognitive functioning and well-being in euthyroid patients with primary hypothyroidism on adequate thyroxine (T4) treatment. We also investigated whether serum TSH and thyroid antibodies are determinants of neurocognitive functioning and well-being.


METHODS
We assessed neurocognitive functioning and well-being in 141 patients with primary hypothyroidism.


METHODS
Neurocognitive test results and scores on questionnaires measuring well-being of 141 patients were compared with the reference values for these tests as published and used in Dutch clinical neuropsychological practice. Assessment of neurocognitive functioning included tests for cognitive or psychomotor speed, attention, working memory as well as learning and memory. Well-being was measured with the Symptom Check List-90 total score and the Rand 36-item Health Survey subscales for 'mental health' and 'vitality'.


RESULTS
Patients showed poor performance on various domains of neurocognitive functioning compared with mean standard reference values, especially on a complex attention task and on verbal memory tests. Levels of well-being were significantly lower for patients compared with those of the general population. Neither serum TSH nor thyroid antibodies were determinants of neurocognitive functioning and well-being.


CONCLUSIONS
The results of this study suggest that neurocognitive functioning as well as psychological well-being may not be completely restored in patients with hypothyroidism, despite T4 treatment.
Wekking
Ellie M
EM
Department of Psychiatry, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands. ewekking@fsw.leidenuniv.nl
Appelhof
Bente C
BC
Fliers
Eric
E
Schene
Aart H
AH
Huyser
Jochanan
J
Tijssen
Jan G P
JG
Wiersinga
Wilmar M
WM
D000328:Adult; D000368:Aged; D000906:Antibodies / Q000032:analysis; D001288:Attention; D001327:Autoimmune Diseases / Q000188:drug therapy* / Q000523:psychology; D003071:Cognition / Q000187:drug effects*; D003072:Cognition Disorders / Q000209:etiology*; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D007037:Hypothyroidism / Q000150:complications / Q000188:drug therapy* / Q000523:psychology; D007453:Iodide Peroxidase / Q000276:immunology; D008297:Male; D008568:Memory; D008603:Mental Health; D008875:Middle Aged; D013974:Thyroxine / Q000627:therapeutic use*
D000906:Antibodies; D007453:Iodide Peroxidase; D013974:Thyroxine