Psychopharmacology: lithium and the parathyroid: 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 · Psychopharmacology: lithium and the parathyroid

Sample item

A woman on lithium for bipolar disorder for eight years has constipation, polyuria and a serum calcium that is above the normal range with a raised parathyroid hormone. What is the most likely explanation?

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

The answer and the reasoning

A. Lithium-induced hyperparathyroidism

Long-term lithium resets the calcium set point of the parathyroid cells, causing hypercalcaemia with raised PTH. Serum calcium should be checked periodically during treatment.

Option by option

  • A. Lithium-induced hyperparathyroidism (correct)

    Correct. Lithium shifts the parathyroid set point, producing hypercalcaemia with raised PTH.

  • B. Vitamin D toxicity

    Vitamin D toxicity gives hypercalcaemia with suppressed PTH, not a raised level.

  • C. Malignancy-related hypercalcaemia from bone metastases

    Malignant hypercalcaemia suppresses PTH and is not suggested by the history.

  • D. Lithium-induced hypoparathyroidism

    Hypoparathyroidism would give low calcium and low PTH.

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.

More Psychiatry questions

Questions about this Psychiatry question

What is the answer to this Psychiatry question?

The best answer is A, Lithium-induced hyperparathyroidism. Long-term lithium resets the calcium set point of the parathyroid cells, causing hypercalcaemia with raised PTH.

Why is "Vitamin D toxicity" not the answer?

Vitamin D toxicity gives hypercalcaemia with suppressed PTH, not a raised level.

Why is "Malignancy-related hypercalcaemia from bone metastases" not the answer?

Malignant hypercalcaemia suppresses PTH and is not suggested by the history.

Why is "Lithium-induced hypoparathyroidism" not the answer?

Hypoparathyroidism would give low calcium and low PTH.

What concept does this question test?

It tests Psychopharmacology: lithium and the parathyroid in Psychiatry. Serum calcium should be checked periodically during treatment.

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 Psychopharmacology: lithium and the parathyroid?

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.