Beyond Diagnosis: Why Psychological Formulation Matters in Mental Health Care

A diagnosis can describe a recognised pattern of difficulties. A psychological formulation asks a different question: how might this particular person’s difficulties have developed, what may be keeping them going, and what could help?

These are not rival questions. Diagnostic classification and formulation do different jobs. A diagnosis can give clinicians a shared term, connect someone with relevant evidence and services, and support communication, research and treatment decisions. A formulation tries to build an individual explanation from the person’s history, present circumstances, strengths and patterns of coping.

That distinction matters because two people who meet criteria for the same diagnosis may have arrived there by very different routes. Their sleep, physical health, relationships, learning history, beliefs, cultural context and current pressures may differ, as may the processes that keep their difficulties going. Formulation is one way of organising those differences into a working account that can guide care.

What psychological formulation actually means

The British Psychological Society’s current guidance describes formulation as ongoing, collaborative sense-making based on the person’s account and informed by psychological evidence, theory and principles. It aims to understand core difficulties in the context of strengths and social, environmental, biological, cultural and relational factors. The result should inform a shared plan and remain open to revision.

In plainer language, formulation brings assessment information into a coherent explanation. It may ask: What has happened? What is happening now? What appears to trigger or intensify the difficulty? What keeps the pattern going? What strengths, relationships or resources are available? Which changes are most likely to help?

A formulation is therefore more than a chronology and more than a list of possible causes. It links information. If poor sleep, threat-focused attention, withdrawal and conflict all appear relevant, a formulation considers how they may interact. The links are hypotheses, not discovered facts. They should be tested against the person’s experience, clinical observations, relevant theory and what happens when circumstances or interventions change.

Diagnosis and formulation answer different questions

Diagnostic systems such as the World Health Organization’s ICD-11 clinical manual identify recognisable patterns of symptoms and impairment. Standardised terminology helps practitioners communicate across services and countries. It also allows cases to be counted, research samples to be defined and knowledge about course or treatment to accumulate. In some health systems, a diagnosis affects eligibility for specialist care, support or insurance.

Those functions are real even when a category is imperfect. Robert Kendell and Assen Jablensky drew a useful distinction between diagnostic validity and utility. Many psychiatric categories have not been shown to be discrete diseases separated by clear natural boundaries, they argued, yet can still be useful because they convey information about presentation, prognosis or likely treatment response. Usefulness depends on the diagnosis, purpose and context; it should not be confused with a complete causal explanation.

Formulation works at a different level. It asks why these difficulties may have emerged for this person, at this point, and through which mechanisms they continue. It can include a diagnosis, but is not determined by one. The same diagnostic term may sit within formulations that emphasise different patterns of avoidance, interpersonal threat, loss, sleep disruption, pain, social exclusion or neurodevelopmental needs.

Nor does formulation make diagnosis redundant. A detailed personal account cannot replace every function of classification, just as a category cannot replace an individual understanding. The 2025 BPS guidance treats assessment, formulation and, where appropriate, diagnosis as related and revisable parts of practice rather than mutually exclusive camps.

Building an individual psychological explanation

The 5 Ps are a framework, not a formula

One widely used organising structure is the 5 Ps:

• Presenting problems: the current difficulties, their effects and the person’s priorities.
• Predisposing factors: earlier or longer-term influences that may have increased vulnerability.
• Precipitating factors: events or changes associated with the onset or recent worsening of the problem.
• Perpetuating factors: processes that may be maintaining the difficulty now.
• Protective factors: strengths, relationships, skills, values, resources and conditions that support safety or recovery.

The categories can prevent important information from being overlooked, but they are not a universal recipe. Cognitive-behavioural, systemic, psychodynamic, cognitive analytic and other approaches organise explanations differently. Even within one approach, the level of detail depends on the setting and purpose. A brief primary-care formulation and a multidisciplinary account for a complex inpatient presentation will not look the same.

Biology, psychology and context can interact

A useful formulation may draw from several domains. Biological and embodied factors might include physical illness, pain, sleep, medication effects, hormonal changes, neurodevelopmental differences or physiological sensitivity to stress. Psychological factors may include beliefs, emotions, memory, attention, learning history and coping strategies. Social and contextual factors can include relationships, caregiving, work, housing, poverty, discrimination, culture, community and access to support.

This is not an instruction to include everything. A formulation should be selective and relevant, with a reason for each proposed link. Listing “bio-psycho-social” headings without explaining how the factors interact produces a catalogue, not an explanation. Conversely, locating the entire problem inside the individual can hide conditions that continue to generate distress. Our article on psychologically informed crisis care for adults with learning disabilities illustrates why communication, health, environment and support arrangements may need to be understood together in a complex presentation.

Trauma may be central for some people. Experiences of violence, abuse, neglect, loss or coercion can shape threat expectations, relationships, bodily responses and coping. But formulation should not assume trauma when evidence is absent, treat every difficulty as a trauma response or press a person into a predetermined story. The task is to understand the meaning and effects of experiences that are relevant, at a pace and level of detail that are appropriate.

Why maintaining factors matter

Predisposing influences and triggers help explain how a difficulty began. Maintaining mechanisms point towards what might be changed now. This is one of formulation’s most practical contributions.

Consider avoidance. Leaving a feared situation can bring immediate relief, which makes avoidance more likely next time. Yet repeated avoidance may prevent new learning that the situation is manageable, narrow daily life and preserve a sense of threat. Reassurance seeking can work similarly: it may reduce uncertainty briefly while making independent confidence harder to build. Rumination can feel like problem-solving but keep attention fixed on threat or loss. Withdrawal may conserve energy during distress while also reducing activity, connection and sources of reward.

Other cycles may involve disrupted sleep, heightened bodily monitoring, threat interpretations, conflict, inconsistent responses from others or patterns of reinforcement. These examples are educational, not diagnoses. They do not mean that people deliberately maintain their difficulties. Many maintaining processes begin as understandable attempts to cope or stay safe. The point is to identify a cycle without assigning blame.

Protective factors belong in the same account. A trusted relationship, stable housing, humour, cultural identity, practical skill, meaningful role, faith community or previous experience of recovery may alter both risk and intervention. Strengths are not an optimistic appendix to a problem-focused story; they help explain why difficulties are not worse and what change can build upon.

Formulation should be collaborative, not something done to a person

A formulation carries power. A clinician selects information, applies concepts and writes an account that may influence how other professionals respond. If that account is created privately and presented as the truth, it can reproduce the very assumptions it is meant to question.

Collaboration means more than asking whether the person agrees at the end. It involves using their language where possible, checking meanings, making uncertainty visible and allowing disagreement. It may include timelines, diagrams, written narratives or conversations, depending on the person’s preferences and communication needs. A formulation should change when new information emerges or when its predictions do not hold.

A 2024 qualitative systematic review by Naomi Thrower and colleagues synthesised 19 studies of client and clinician experience. Collaboration was supported by preparation, a safe therapeutic relationship, accessible initial formulations and shared activities. The review also found that formulation can be confusing or emotionally difficult, and that time, resources and team dynamics can impede collaboration. A process described as collaborative is not necessarily experienced that way.

Cultural humility is part of this work. Beliefs about distress, family, independence, spirituality and professional help vary within as well as between groups. Housing insecurity, racism or unemployment should not be translated automatically into an individual cognitive deficit. Equally, a clinician should not impose a cultural explanation that the person does not recognise. Trust also matters: as discussed in our article on why people delay seeking psychological help, willingness to seek or continue care is shaped by service design and previous encounters as well as personal attitudes.

How formulation can influence intervention

A formulation earns its place when it improves decisions. It can help a clinician and client agree priorities, select an evidence-based intervention, adapt its delivery and anticipate obstacles. A maintenance cycle centred on avoidance suggests different targets from one dominated by sleep disruption, interpersonal threat or medication side effects. Protective factors may identify who or what can support change.

Formulation can also organise multidisciplinary work. Different professionals may hold pieces of the pattern: physical health information, behaviour observed at home, occupational demands, communication needs or changes in medication. A shared account can connect those observations and clarify responsibilities. NICE, for example, recommends a written formulation as the basis of the care plan when assessing mental health problems in people with learning disabilities.

But formulation is not itself a treatment. A plausible diagram does not improve symptoms unless it leads to appropriate action, and the intervention still requires its own evidence. Formulation should not become a reason to abandon established treatment guidance or endlessly search for a perfect explanation before offering help.

Where formulation has limitations

Professional enthusiasm is stronger than parts of the empirical evidence. In a systematic review of 18 studies, Lucinda Flinn and colleagues found that agreement between formulators ranged widely, from slight to substantial. Training and experience sometimes improved reliability, but study methods were heterogeneous and only one study examined stability over time. A separate review by Sandra Bucci and colleagues found no single measure of formulation quality validated across varied settings and client groups.

Outcome evidence is also limited. A systematic review of team formulation found weak support for claimed benefits because practices were inconsistently defined and evaluations had substantial methodological problems. Research on particular formulation-based therapies cannot automatically establish that formulation itself caused the outcome; the effect of the broader treatment is difficult to separate from the explanatory process used to tailor it.

There are conceptual risks too. Different clinicians can construct different accounts from the same information. A coherent story may feel convincing even when key links are speculative. Confirmation bias can lead a practitioner to notice evidence that fits a preferred model and discount what does not. Professional language can disguise assumptions about culture, gender, family life or acceptable behaviour. Overemphasis on early experience may neglect present conditions; excessive focus on current maintaining factors may minimise trauma or structural adversity.

A 2024 Delphi study of UK clinical psychologists illustrates both agreement and uncertainty. Participants reached consensus on the importance of collaboration, hypotheses, strengths, personal meaning, sociocultural and biological factors. They did not agree on every proposed component, including whether formulation must adhere to a particular model. “Formulation” is not one standardised procedure with uniform evidence.

These limitations argue for disciplined use, not abandonment: state uncertainty, distinguish observation from inference, seek the person’s view, use supervision, consider alternative explanations and revise the account in response to evidence. Sometimes the most accurate formulation will be deliberately modest.

Diagnosis or formulation? Why the answer may be both

Diagnosis compresses information into a category. Formulation expands the view to explain an individual pattern in context. Compression makes communication and research possible; expansion supports personal meaning and tailored decisions. Each loses something the other can preserve.

The sensible question is therefore not which approach wins, but what each contributes in a particular setting. A diagnosis may identify a clinically useful syndrome and open a route to care. A formulation may clarify why the problem has taken this form, why it has intensified now, what keeps it going and which resources can support change. Both should be reviewed when the evidence changes.

At its best, formulation is neither an elegant story imposed by an expert nor a rejection of medical knowledge. It is a transparent, collaborative and testable attempt to understand a person’s difficulties without losing sight of their body, relationships, culture, circumstances and strengths. Its value lies not in claiming certainty, but in improving the questions care is able to ask.

This article provides general educational information and is not a substitute for individual psychological or medical assessment, diagnosis or treatment.

References

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Thrower, N. E., Bucci, S., Morris, L., & Berry, K. (2024). The key components of a clinical psychology formulation: A consensus study. British Journal of Clinical Psychology, 63(2), 213–226. https://doi.org/10.1111/bjc.12455

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