Paper A is a three-hour written paper of 150 questions worth 150 marks, covering the scientific and theoretical basis of psychiatry, and the single most useful thing you can do before starting your revision is look at how the marks are actually distributed. Most candidates do not, and they allocate their time by instinct, which means they spend it on the material they find interesting and neglect the two domains that between them account for half the paper. The blueprint is published. Reading it takes two minutes and will change how you spend the next three months.
Key takeaways
- Paper A is 150 questions in three hours, roughly two-thirds multiple choice and one-third extended matching items.
- Basic neurosciences and clinical psychopharmacology carry 25 per cent each, so together they are half the paper.
- The other three domains carry roughly 17 per cent each, which is a third less than most candidates assume.
- Establish coverage across all five domains before letting adaptive practice narrow your focus.
- Space the named theories, pathways and drug mechanisms, because they interfere with each other and decay.
The weighting nobody looks at
Here is the distribution, and it is worth committing to memory.
| Domain | Approximate weight |
|---|---|
| Basic neurosciences | 25 per cent |
| Clinical psychopharmacology | 25 per cent |
| Behavioural science and sociocultural psychiatry | 17 per cent |
| Human development | 17 per cent |
| Classification and assessment in psychiatry | 17 per cent |
Two domains, half the marks. And they are the two that candidates most often postpone, because neuroscience feels like a return to preclinical study and psychopharmacology feels like a list of drugs to be learned nearer the time.
Meanwhile, a great deal of revision effort goes into the named psychological theories and the classification systems, which are genuinely examinable and are worth two-thirds of what the neuroscience is worth. That is not an argument for neglecting them. It is an argument for weighting your hours to the paper rather than to your preferences.
Psychopharmacology is derivable, not memorable
The reason candidates dread psychopharmacology is that they approach it as a list: this drug, these side effects, that interaction, repeat for forty drugs. Approached that way it is enormous and it does not stick.
Approached through the receptor, it collapses.
Almost every side effect in psychopharmacology follows from a receptor action, and once you know the receptor profile of a drug you can predict its clinical effects and its adverse effects rather than remembering them. Dopamine blockade in the nigrostriatal pathway produces extrapyramidal effects; in the tuberoinfundibular pathway it raises prolactin. Histamine blockade produces sedation and weight gain. Muscarinic blockade produces the anticholinergic syndrome. Alpha-one blockade produces postural hypotension. Serotonergic actions produce their own characteristic profile.
So when you meet a new agent, do not learn its side effects. Learn its receptor profile, and derive them. The exam is testing whether you can do exactly that, and the questions are frequently written as: here is a patient with this adverse effect, which receptor action explains it, or which drug would you expect to produce it.
We take this further in mechanism, adverse effect or interaction.
Neuroscience: build the map before the detail
The other quarter-weight domain rewards structure over volume.
Get the anatomy and the pathways secure first: the neurotransmitter systems and where they run, the circuits implicated in the major disorders, the functional anatomy that explains the clinical syndromes. Then hang the detail on that frame, because detail without a frame is what decays.
Then the material that recurs every diet: receptor types and their subtypes, second messenger systems, the neurochemistry of the major disorders, neuroimaging findings and what they mean, genetics and heritability, and the neuroscience underlying the drug actions you have just derived.
Notice that the neuroscience and the psychopharmacology are not two subjects. They are one subject asked from two directions, and revising them together halves the work.
Cover before you optimise
The sequencing point that applies to every exam and applies here with force, because Paper A's domains are so distinct.
Work first in Standard mode across all five domains, sampling deliberately, and record two figures for each: your accuracy, and how many questions you have actually attempted. A domain with low exposure is not a strength, it is an unknown, and Paper A candidates routinely arrive with entire domains unexamined because they never got to them.
Only once every domain has cleared a reasonable exposure threshold does adaptive practice earn its place, because an engine can only target the weaknesses it has seen.
Space what interferes
Paper A is unusually full of material that blurs, and blurred material produces confident wrong answers under time pressure rather than useful hesitation.
The named psychological theories, with their similar-sounding stages and their overlapping claims. The developmental frameworks, which candidates persistently confuse with each other. The classification systems and their criteria, which differ in specific and testable ways. The pathways, the receptor subtypes, the drug mechanisms.
Reading this material produces recognition. Retrieval, spaced at increasing intervals, produces the discrimination the exam demands, and it is the only thing that does. Build it into your preparation from the start rather than hoping a final revision pass will separate concepts you have never actively retrieved.
Practise the extended matching items specifically
Roughly a third of the paper is extended matching, and it is a distinct technique that rewards deliberate practice.
The trap in an extended matching set is that a single option list serves several stems, and candidates match by resemblance rather than working each stem properly. The option lists are deliberately populated with plausible near-misses, so pattern-matching across a shared list is exactly the behaviour the format punishes.
Work each stem independently. Decide what you think the answer is before you look at the list where you can, and resist the pull of an option simply because it seems to fit the general theme.
Pace it deliberately
Three hours for 150 questions is a little over a minute per question, which is workable, but the two question types do not consume time equally: extended matching items generally take longer to read and work through than single best answers.
So plan the paper rather than discovering it. Many candidates find it works to complete the multiple choice questions first, at pace, and to reserve a substantial block at the end for the extended matching sets, rather than meeting them tired and short of time. Whatever you choose, rehearse it in a timed full-length mock, because a pacing plan you have never executed is a hope rather than a plan.
Where iatroX fits
iatroX's MRCPsych Paper A bank is mapped to the syllabus with its actual weighting, so your practice reflects the paper rather than your preferences, and it tracks the five domains separately so that a neglected quarter-weight domain cannot hide behind a healthy overall percentage. The adaptive engine targets the domains you are genuinely weak in, spaced repetition returns the theories, pathways and drug mechanisms that interfere with each other, and missed questions can be opened in the Socratic Tutor, which asks you to reason from the receptor or the mechanism before it explains. Try it with free sample questions at iatroX. For the coverage audit that should precede all of this, see using Standard mode as a syllabus audit.
Frequently asked questions
What is the format of MRCPsych Paper A? A three-hour written paper of 150 questions worth 150 marks, made up of approximately two-thirds multiple choice questions and one-third extended matching items, covering the scientific and theoretical basis of psychiatry.
Which Paper A domains carry the most marks? Basic neurosciences and clinical psychopharmacology, at roughly 25 per cent each, which means they account for half the paper between them. The other three domains carry about 17 per cent each.
How should I revise psychopharmacology? Through the receptor rather than through lists. Learn a drug's receptor profile and derive its clinical and adverse effects from it, because the exam frequently asks you to explain an adverse effect by naming the receptor action responsible.
How should I handle the extended matching items? Work each stem independently rather than matching by resemblance across the shared option list, since the lists are deliberately populated with plausible near-misses. They also take longer to read, so plan your pacing and rehearse it in a timed mock.