4 Classification and assessment in psychiatry4.3 Clinical assessment
4.3.4 Biopsychosocial formulation
2 min read
Written by Resident Doctor Committee · Published
New in the 2027 syllabus
The College added this topic for exams from January 2027.
What a formulation is
A formulation is a working explanation of a person's problems. It links their difficulties, history, strengths and circumstances into one account. It guides treatment, and it is provisional, so you revise it as you learn more.
A diagnosis names a syndrome. A formulation asks different questions: why has this person developed these problems, why now, and what keeps them going?
Build the formulation with the person. Check your account against their own view. Do not present it as an explanation of their life that they cannot challenge.
The four Ps
Factor | Question | Examples |
|---|---|---|
Predisposing | What made the person more vulnerable before the problem began? | Familial risk, early adversity, longstanding beliefs |
Precipitating | What happened just before this episode? | Sleep loss, bereavement, a change in medication |
Perpetuating | What keeps the problem going now? | Avoidance, continuing abuse, substance use, adverse effects |
Protective | What lowers risk or helps recovery? | Relationships, skills, secure housing, effective treatment |
Biological, psychological and social factors
Biological: illness, development, sleep, substances and medicines. Look for physical causes and for the effects of treatment. Do not assume every symptom is psychological.
Psychological: what events mean to the person, how they cope, what they have learned, their emotions and how they tend to relate to others.
Social: relationships, discrimination, money, housing, work and access to care.
The factors interact. Insomnia can make worry worse, and worry can cut sleep further. Overcrowded housing can keep both going.
Using the formulation to plan treatment
Take an invented example. A person with panic stops using buses after a frightening episode. Avoiding buses brings immediate relief. But it also stops new learning, because they never find out whether what they fear really happens. It puts their job at risk too, which adds to their stress.
Clarify the pattern. Establish the symptoms, the triggers and the outcome they fear. Look for medical or substance-related contributors.
Identify what keeps it going. Test the suggested link: avoidance brings short-term relief, and the fear continues.
Agree treatment. Consider a graded behavioural plan, alongside practical help with travel and employment.
Review the hypothesis. Use the person's experience and the outcome to revise the formulation.
Limits
An association does not prove cause. A plausible story must not turn uncertain memories or family assumptions into established facts.
The person's strengths and preferences affect which interventions they will accept and which will work in practice.
Expect to revise the formulation when new evidence appears, when circumstances change, or when treatment does not bring the benefit you predicted.