This looks like an interesting piece of research on how patients who undergo a thyroidectomy are affected by hypothyroidism. The conclusion seems to point to anxiety rather than depression triggered by hypothyroidism as the interfering factor for executive function. The research was undertaken on thyroid cancer patients. It speculates that the sudden loss of hormone function through thyroidectomy may cause anxiety that affects executive function in a different way from slowly progressing or long term thyroid failure.
I found this interesting because I've been thinking about the different experiences of people who have thyroidectomy and those with reduced thyroid function through autoimmune thyroid disease. I've wondered what differences existed and how treatment options should differ as a result. I think it's still an unanswered question but research like this might help to piece it together.
"...this particular model of hypothyroidism (acute short-term hypothyroidism) differs from spontaneous hypothyroidism, which is often milder and slowly progressive (chronic long-term hypothyroidism). Indeed, one could argue that the unexpected finding of the prevalent interference effect of anxiety was the consequence of a sudden decline of circulating thyroid hormone in short-term hypothyroidism, which
induces marked discomfort that is quite different from the insidious symptoms typical of long-term thyroid failure.
Even if increased anxiety could be explained in part by awaiting the result of scintigraphy, this would not be the only explanation. The participants knew that the probability of having a recurrence of the disease was very low, as they all had had a low-risk well-differentiated thyroid carcinoma. A similar procedure that involved withdrawing thyroid hormones had already been done twice in the past."
Anxiety and depression, attention, and executive functions in hypothyroidism (PDF Download Available). Available from: researchgate.net/publicatio... [accessed Jan 24 2018].