Naming Hildegard Peplau’s Interpersonal Relations Theory in your introduction and then never returning to it is the single fastest way to have a theoretical-framework chapter sent back. This guide develops Peplau’s theory end to end for a psychiatric-mental health nursing thesis: what the theory actually says, how to derive research questions or coding categories directly from its structure, how to align a data-collection instrument with it, and a worked theoretical framework example showing every piece connected. For the broader distinction between a theoretical and a conceptual framework before you commit to this one, see our guide to theoretical versus conceptual frameworks.

What Peplau’s theory actually says

Peplau’s Interpersonal Relations in Nursing was published in 1952, and the theory is widely regarded as one of the first formally published nursing theories. It centers the nurse-patient relationship itself — not a diagnosis, not a procedure — as the core unit of nursing practice. Peplau described nursing as a fundamentally interpersonal process built on observation, description, formulation, interpretation, validation and intervention, moving through four distinct phases.

The four phases: your natural chapter or coding structure

1. Orientation. The initial meeting, in which trust begins to form and both nurse and patient clarify their respective roles and the reason for the relationship.
2. Identification. The patient begins to identify the specific problems the relationship will work on, and begins responding to those who can help meet the identified need.
3. Exploitation (or Working). Nurse and patient actively collaborate toward the health goals identified in the previous phase — the phase where most of the therapeutic work happens.
4. Resolution (or Termination). The relationship concludes once its goals are met, and the patient moves toward independence from the nurse.

These four phases give a thesis its most natural structure for either a qualitative coding framework (coding interview or observation data against which phase a described interaction belongs to) or a quantitative variable set (measuring, for example, patient-reported trust or engagement at each phase transition). A thesis committing to the qualitative route should say explicitly whether the coding is deductive (categories fixed in advance from the theory, the standard approach for a theory-driven design like this one), inductive, or a combination, since a purely inductive approach sits awkwardly alongside a claim to be “applying” a named theory.

The six nursing roles: a second axis for your analysis

Alongside the four phases, Peplau identified six distinct roles a nurse assumes across the therapeutic relationship: Stranger (the initial, unfamiliar-to-each-other role at first contact), Resource (providing specific needed information), Teacher (facilitating learning), Counselor (helping the patient understand and integrate their experience), Surrogate (standing in for another significant figure in the patient’s life, a role Peplau treated carefully given its transference implications), and a Leadership role (guiding the therapeutic process). A thesis applying Peplau’s theory fully should show which roles appear in its data and how they map onto the four phases — a Stranger-role interaction belongs naturally to Orientation; a Counselor-role interaction belongs more often to Exploitation. Treating phases and roles as two intersecting axes, rather than picking only one, is what separates a full application of the theory from a partial one.

Deriving research questions or coding categories from the theory

For a qualitative design (the most common fit for this theory): build your interview guide or observation coding scheme directly around the four phases and six roles. A sample research question: “How do psychiatric nurse-patient relationships progress through Peplau’s four phases in a short-stay inpatient setting, and which of Peplau’s six roles are most salient at each phase?” Your coding categories would then be the phases and roles themselves, applied deductively to interview transcripts or observation notes, rather than invented inductive codes unconnected to the theory. Our data collection instrument templates guide covers how to build the semi-structured interview guide this design needs.

For a quantitative design: operationalize a specific construct tied to one phase — for example, measuring therapeutic alliance (a close conceptual relative of Peplau’s Exploitation phase) at defined intervals using a validated therapeutic-alliance instrument, and testing whether alliance scores change as patients move through the phases Peplau describes. The theory supplies the conceptual structure; a validated instrument supplies the actual measurement. The variable-naming and hypothesis-writing discipline this requires is the same one covered in our guide to research questions, hypotheses and variables for a psychology dissertation, which applies equally to a psychiatric nursing thesis using a quantitative Peplau-framed design.

A worked theoretical framework example

Weak version: “This study is guided by Peplau’s theory of interpersonal relations, which describes the nurse-patient relationship.” (One sentence, then the theory never reappears.)

Full application: “This study applies Peplau’s (1952) four-phase model of the nurse-patient relationship (Orientation, Identification, Exploitation, Resolution) as the coding framework for semi-structured interviews with psychiatric-mental health nurses. Interview questions were designed to elicit examples of practice at each phase; deductive coding assigned each excerpt to a phase and, where applicable, to one of Peplau’s six nursing roles (Stranger, Resource, Teacher, Counselor, Surrogate, Leadership). The discussion chapter interprets findings against this framework directly — for example, discussing why Surrogate-role interactions clustered disproportionately in the Exploitation phase rather than appearing evenly across all four.”

The second version traces the theory through data collection, coding and discussion — exactly the “used, not just named” standard a theoretical-framework chapter needs to meet.

Citing the primary source correctly

Peplau’s original 1952 text, Interpersonal Relations in Nursing, is the primary source and should be cited directly for the theory’s original formulation, phases and roles, rather than relying solely on a secondary textbook summary. Where a secondary source is used for convenience (many nursing-theory textbooks summarize Peplau accurately), cite it alongside the primary reference rather than instead of it, and note explicitly which edition or reprint of Peplau’s work you consulted if it differs from the 1952 original, since the theory has been reprinted and lightly annotated in later editions.

Ethical considerations specific to a Peplau-framed study

Because the theory centers the nurse-patient relationship itself as the object of study, a Peplau-framed thesis raises two ethical questions a more distant, measurement-only design does not. First, if nurse participants are describing their own relationships with specific patients, the consent and confidentiality plan needs to protect the patient side of that relationship even though patients are not themselves study participants — de-identify patient details in every interview excerpt, not just the nurse participant’s own identity. Second, research involving a psychiatric-mental health population directly (rather than nurses describing their relationships with patients) requires the heightened protections most IRBs apply to a population that may have diminished capacity to consent at some points in their care; a study design that interviews patients only during periods of clinical stability, with a documented capacity assessment, is the standard approach.

Where the theory does and does not fit

Peplau’s theory originated in, and remains most strongly associated with, psychiatric-mental health nursing because of its focus on a sustained therapeutic relationship — but it is not exclusively a psychiatric theory. Any setting where a nurse-patient relationship develops over multiple contacts (chronic disease management, a long-term rehabilitation unit, a maternal-child health home-visiting program) can support a Peplau-framed study. It fits less naturally in single-contact or acute-episode settings (a single emergency-department visit, for example) where the four-phase progression has little room to unfold — a thesis proposing Peplau’s theory for a single-contact setting should address explicitly why the phase structure still applies, or choose a different framework better suited to brief encounters. For the methodology decisions this framework choice feeds into — QI versus research classification, IRB route, and analysis plan — our guide to the methodology chapter of a nursing dissertation or DNP project covers the surrounding structure this chapter sits inside.

A note on adapting the theory to a DNP quality-improvement project

Where a psychiatric-mental health DNP project is framed as quality improvement rather than generalizable research, Peplau’s phases still work well as an evaluation structure — for example, assessing whether a new admission protocol shortens the time a unit spends in the Orientation phase before patients begin engaging with treatment goals. Keep the QI framing explicit throughout: the theory supplies the conceptual lens for evaluating a local practice change, not a claim that the findings generalize beyond the unit where the project ran.

Mistakes that get a Peplau-framed chapter flagged

• The theory named but never operationalized — no coding scheme, no variable, no explicit return to the phases or roles in the discussion.
• Only the phases used, roles ignored (or vice versa) — treating the theory as one axis when it offers two.
• Secondary-source-only citation — never citing Peplau’s 1952 primary text directly.
• Applied to a setting with no room for phase progression without addressing the mismatch explicitly.
• Confusing Peplau’s Surrogate role with countertransference as a clinical concept — related, but not identical, and the thesis should be precise about which concept it is invoking.
• No stated coding approach — claiming a theory-driven design without saying whether coding was deductive, inductive, or a mix.
• Patient de-identification limited to the participant only — forgetting that a nurse participant’s description of a patient also needs de-identification, even though the patient is not directly enrolled.

Frequently asked questions

Who developed the Interpersonal Relations Theory and when?

Hildegard Peplau developed it in Interpersonal Relations in Nursing, published in 1952, and it is widely regarded as one of the first formally published nursing theories.

What are the four phases of Peplau’s theory?

Orientation, Identification, Exploitation (or Working), and Resolution (or Termination) — describing the progression of the nurse-patient relationship from initial contact to the relationship’s conclusion.

What are Peplau’s six nursing roles?

Stranger, Resource, Teacher, Counselor, Surrogate, and Leadership — each describing a function the nurse performs at different points in the therapeutic relationship.

Is Peplau’s theory only usable in psychiatric-mental health nursing?

No, though it is most associated with psychiatric-mental health nursing because of its focus on the therapeutic nurse-patient relationship; it has been applied in other specialties wherever a sustained interpersonal relationship is central to care.

How is Peplau’s theory different from a nursing theory catalogue or comparison?

A catalogue lists several theories and matches each to the kind of study it fits. Applying Peplau’s theory end to end means developing one theory fully — deriving your research questions, coding categories or variables directly from its four phases and six roles, not just naming it.

Can Peplau’s theory support a quantitative design, or only qualitative?

It fits qualitative designs most naturally, but a quantitative design can operationalize a construct tied to one phase — such as therapeutic alliance for the Exploitation phase — using a validated instrument, then test whether that construct changes as the relationship progresses.

Do I need special ethics protections if I am interviewing psychiatric patients directly?

Yes. Most IRBs apply heightened protections for a population that may have diminished capacity to consent at some points in care — interviewing only during documented periods of clinical stability, with a capacity assessment, is the standard approach.

Apply your chosen nursing theory all the way through

Tesify’s thesis workspace, used by 9,000+ students and 15,000+ chapters, helps psychiatric-mental health nursing students trace a chosen theory like Peplau’s from the framework chapter through coding and discussion. Every word stays 100% written by you.