EGM clinical caseDepression: An unrecognized presentation of hyperthyroidism in old age
Introduction
It is well documented that symptoms of hyperthyroidism may be similar to those observed in patients with psychiatric disease, most commonly affective disorders. Classical manifestations reported include dysphoria, anxiety, emotional lability, tremor, restlessness and rapid speech. Overactivity of the adrenergic system caused by hyperthyroidism might explain the similarity to clinical manifestations of mania and anxiety [1].
However, hyperthyroidism can also present with symptoms more frequently described in hypothyroid states, namely suggestive of depression - apathy, lethargy, fatigue, anorexia and decreased cognition. Such an atypical presentation is especially frequent in older people, and was first described as apathetic thyrotoxicosis by Lahey in 1931 [2]. The pathogenesis of depression in hyperthyroid states in less clear: prolonged hyperthyroidism might exhaust noradrenergic transmission and therefore contribute to depression [1].
Section snippets
Clinical case
We report the case of MB, a 67-year-old woman whose psychiatric admission to our Day Care Hospital was due to a depressive episode unresponsive to antidepressant treatment. At admission, depressive mood, anhedonia and anergia were remarkable. Biological rhythms were unaltered. Intravenous clomipramine was initiated (maximum dose of 225 mg id), but after two weeks no improvement was apparent.
Further assessment brought to attention that the patient had been medicated with levothyroxine (0.150 mg
Discussion
Mood disorders attributed to the effect of medications rely on clinical judgment about causality. Such causal relationships are characterized by a temporal relationship between drug administration and the onset of the mood episode, positive cases of de-challenge and re-challenge with the substance, and plausibility for a biological role.
In our clinical case, the withdrawal of levothyroxine and subsequent normalization of TSH levels were quickly followed by clinical improvement of the depressive
Disclosure of interest
The authors declare that they have no conflicts of interest concerning this article.
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Depression in old age, part 2: Comorbidity and treatment
2016, Zeitschrift fur Gerontologie und Geriatrie