Eating and sleep disorders: amenorrhoea in anorexia nervosa: practice question

A Psychiatry question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

Try it

Psychiatry · Eating and sleep disorders: amenorrhoea in anorexia nervosa

Sample item

A 16-year-old with a BMI of 14 has had no periods for 8 months. Which endocrine mechanism accounts for the amenorrhoea?

AHypothalamic suppression with low GnRH, LH and FSHBPrimary ovarian failure with raised FSHCHyperprolactinaemia from a pituitary adenomaDRaised LH to FSH ratio with excess androgens

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

A. Hypothalamic suppression with low GnRH, LH and FSH

Starvation and low energy availability suppress hypothalamic GnRH pulses, so LH, FSH and oestradiol fall. This is functional hypothalamic amenorrhoea and is reversible with weight restoration. Raised FSH, hyperprolactinaemia and a high LH:FSH ratio point to ovarian failure, a prolactinoma and PCOS respectively.

Option by option

A. Hypothalamic suppression with low GnRH, LH and FSH (correct)
Correct. Low energy availability suppresses GnRH pulsatility and so the whole axis.
B. Primary ovarian failure with raised FSH
Primary ovarian failure raises FSH, whereas FSH is low here.
C. Hyperprolactinaemia from a pituitary adenoma
A prolactinoma is a structural pituitary cause and is not the mechanism of starvation amenorrhoea.
D. Raised LH to FSH ratio with excess androgens
A raised LH:FSH ratio with androgen excess is the pattern of PCOS, not of starvation.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Psychiatry question

What is the answer to this Psychiatry question?

The best answer is A, Hypothalamic suppression with low GnRH, LH and FSH. Starvation and low energy availability suppress hypothalamic GnRH pulses, so LH, FSH and oestradiol fall.

Why is "Primary ovarian failure with raised FSH" not the answer?

Primary ovarian failure raises FSH, whereas FSH is low here.

Why is "Hyperprolactinaemia from a pituitary adenoma" not the answer?

A prolactinoma is a structural pituitary cause and is not the mechanism of starvation amenorrhoea.

Why is "Raised LH to FSH ratio with excess androgens" not the answer?

A raised LH:FSH ratio with androgen excess is the pattern of PCOS, not of starvation.

What concept does this question test?

It tests Eating and sleep disorders: amenorrhoea in anorexia nervosa in Psychiatry. This is functional hypothalamic amenorrhoea and is reversible with weight restoration. Raised FSH, hyperprolactinaemia and a high LH:FSH ratio point to ovarian failure, a prolactinoma and PCOS respectively.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Eating and sleep disorders: amenorrhoea in anorexia nervosa?

Learn each diagnosis by its core features and its first-line treatment. Then use the flashcards and the other Psychiatry questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.