Therapists aim to provide interventions that are effective, evidence-based, and aligned with their clients’ needs. And yet, even the most skilled clinicians can find themselves slowly moving away from the structured treatment plan they initially set out to deliver. This gradual shift is known as therapeutic drift, and while it might seem minor in the moment, its impact on treatment fidelity and client outcomes can be significant.
Therapeutic drift can occur across different therapeutic modalities, but in structured, evidence-based treatments such as Cognitive Processing Therapy (CPT) for post-traumatic stress disorder (PTSD), anxiety, depression and similar conditions, the effects of drift are particularly well documented. High-fidelity delivery has been repeatedly linked to stronger symptom reduction, while deviations from the model can dilute its effectiveness (Holder et al., 2018; Keefe et al., 2022; Marques et al., 2019).
By understanding what drift is, why it happens, and how to guard against it, therapists can ensure they are delivering interventions in a way that honours the integrity of the treatment while still adapting appropriately to their clients’ unique needs.
What’s Therapeutic Drift?
Therapeutic drift is defined in various ways, but broadly refers to when a therapist stops using therapeutic methods as intended or loses focus on treatment outcomes. It can also mean the gradual erosion of fidelity – delivering therapy in a way that no longer reflects the original model’s design.
Drawing on the Cambridge Dictionary definitions, drift means “to move slowly, especially as a result of outside forces, with no control over direction,” while fidelity is “the degree to which a copy of something shows the true character of the original”. In therapy, fidelity is about adhering closely to the core components of a treatment, ensuring the delivery mirrors the protocol supported by research.
Outside forces often play a role in drift. For example, changes in policy (like Australia’s reduction in Medicare-funded psychological sessions from 20 to 10 per calendar year) may lead therapists to condense or omit certain components in order to fit within the available sessions. Similarly, organisational restrictions (e.g., session limits, fortnightly attendance policies, or caseload pressures) can alter how therapy is delivered. Even the culture of a workplace or a therapist’s own emotional responses can influence how closely a model is followed.
Why Drift Matters
Therapeutic drift is more than just a deviation from a manual – it has real implications for client outcomes. In trauma therapy especially, evidence consistently shows that higher treatment fidelity is associated with greater improvements in PTSD symptoms, reductions in maladaptive cognitions, and decreased comorbid depression (Holder et al., 2018). Conversely, drifting from the model risks omitting critical components that are key to change.
The concern is heightened when working with clients who may have delayed seeking treatment for decades, as is often the case with PTSD, where research suggests avoidance can last 35-40 years before help is sought (Corvalan & Klein, 2011). For these clients, receiving a diluted or inconsistent form of an evidence-based therapy could mean missed opportunities for meaningful improvement.
Therapeutic drift also intersects with the concept of therapist safety behaviours, described by Waller and Turner (2016), where clinicians avoid pushing clients toward challenging cognitive or behavioural changes in order to protect their own self-image as a positive figure in the client’s life. While well-intentioned, this avoidance can stall progress and undermine the very goals of therapy.
Why Drift Happens: Key Contributing Factors
Therapeutic drift rarely occurs in one sudden leap – it’s usually the result of small shifts over time, shaped by both therapist and systemic influences. Understanding these drivers is crucial to recognising and addressing drift before it undermines treatment.
Client Does Not Initially Respond to Treatment
A common catalyst for drift is a perceived lack of progress in the early sessions. For example, a therapist delivering Cognitive Processing Therapy (CPT) for PTSD might notice little symptom change by session four and feel compelled to “do something different”. This can lead to abandoning the agreed-upon treatment plan instead of re-examining the formulation or collaboratively reaffirming the rationale for the chosen approach.
Rather than making ad-hoc changes, evidence suggests that revisiting the original case formulation, reviewing session content, and troubleshooting barriers within the model can help keep therapy on course.
Belief That Clinical Judgment is Superior to Research
Some clinicians may believe that their individual assessment of a client’s complexity outweighs the value of structured, evidence-based methods. This is often expressed in sentiments such as:
“The clients in my practice are different from the ones in the research – the model doesn’t fit them”.
However, Grove et al.’s (2000) meta-analysis comparing clinical and mechanical prediction found that structured, model-driven approaches were, on average, about 10% more accurate than purely clinical judgment. While experience is vital, overreliance on intuition at the expense of established protocols can lead to the omission of essential therapeutic elements.
Discomfort With Manualised Therapy
Manualised approaches like CPT can be perceived as “cookbook” or “formulaic,” raising concerns that they limit flexibility and responsiveness. In reality, structured therapies often allow for nuanced adaptation while maintaining fidelity. Avoidance of manualised approaches due to discomfort or unfamiliarity can result in drift, particularly if the therapist has not had the opportunity to observe, practise, and receive supervision in the model.
Client Requests for Supportive Counselling
When therapy sessions focus primarily on weekly events without linking back to a shared formulation or therapeutic goals, the process risks becoming supportive counselling rather than targeted intervention. For example, a client may spend sessions recounting stressful events, with the therapist offering empathic listening and general coping suggestions. Without agreed-upon tasks, skill practice, or structured problem-solving, the therapeutic focus can drift away from the evidence-based framework intended to produce measurable change.
Therapist Emotional Reactions
Therapists naturally respond emotionally to their clients’ distress, but fear of causing discomfort can lead to avoidance of necessary therapeutic challenges. Meehl’s (1973) “spun-glass theory of the mind” captures this tendency – treating clients as so fragile that even asking them to confront fears or complete difficult exercises is perceived as potentially harmful. While sensitivity is important, research suggests that carefully guided exposure to challenging material is often critical to progress, especially in trauma-focused interventions.
Multiple Issues Competing for Attention
Clients with multiple presenting problems (like PTSD alongside relationship difficulties) can make it challenging to maintain a focused treatment plan. Drifting between issues without a structured strategy risks diluting therapy’s impact. In these cases, evidence-based practice supports prioritising treatment targets based on their functional impact, while making clear to the client how these priorities fit into a longer-term plan.
External Pressures and Organisational Policies
Drift is not always internally driven – systemic factors can also exert influence. For example, reductions in Medicare-funded psychological sessions in Australia from 20 to 10 per year create pressure to compress treatment, potentially leading therapists to skip or abbreviate key components. Similarly, workplace-imposed session caps, frequency restrictions, or broader organisational cultures can subtly shape how therapy is delivered, sometimes at odds with the original evidence-based protocol.
The Evidence: Fidelity and Client Outcomes
Research in trauma-focused therapies, especially Cognitive Processing Therapy (CPT), offers clear evidence that maintaining fidelity improves client outcomes… sometimes significantly.
- Holder et al. (2018) found that clients treated with high-fidelity CPT experienced significantly greater reductions in PTSD symptoms, negative cognitions, and depressive symptoms compared to those treated with below-average fidelity. The difference was not marginal – fidelity had a measurable, clinically relevant impact.
- Keefe et al. (2022) examined the role of therapist competence and the therapeutic alliance. They found that higher competence in delivering CPT predicted lower next-session PTSD symptoms, particularly when the therapeutic alliance was also strong. In fact, sessions rated high in both competence and alliance produced the most pronounced symptom improvements. This reinforces the point that fidelity and alliance are complementary rather than competing priorities.
- Farmer et al. (2016) explored which aspects of fidelity matter most. They identified critical skills like Socratic questioning and prioritising assimilation before overaccommodation, that were linked to greater improvements in PTSD severity. Interestingly, some elements (e.g., attention to practice assignments or emphasis on expression of natural affect) were less strongly associated with outcomes, suggesting that not all components have equal weight in driving change.
- Marques et al. (2019) studied modifications to CPT in a diverse community health clinic, introducing the concepts of fidelity-consistent and fidelity-inconsistent modifications:
Fidelity-consistent modifications do not alter the treatment’s core elements in a way that reduces adherence to the original protocol. Examples include adapting language for cultural relevance, modifying session length (e.g., extending to 90 minutes for clients with English as a second language), or adjusting examples to suit the client’s lived experience.
Fidelity-inconsistent modifications alter or remove core components, making it harder to distinguish the treatment from other approaches. Examples in CPT include skipping modules, omitting psychoeducation, or integrating unrelated interventions (e.g., adding imaginal exposure exercises from prolonged exposure therapy into CPT).
Marques et al.’s findings showed that higher numbers of fidelity-consistent modifications were associated with larger reductions in post-traumatic stress and depressive symptoms. In contrast, fidelity-inconsistent changes were more likely to compromise outcomes.
Why Fidelity Matters in Practice
Maintaining fidelity does not mean rigidly following a manual without regard to individual differences, but it does mean protecting the treatment’s essential mechanisms of change. In trauma therapy, these mechanisms might include cognitive restructuring, structured exposure to trauma memories, or challenging maladaptive beliefs. When these core components are skipped, replaced, or overshadowed by unrelated techniques, the therapy risks losing its potency. By contrast, thoughtful fidelity-consistent adaptations allow for flexibility while preserving the intervention’s therapeutic “engine”.
Staying on Track: Practical Strategies to Prevent Therapeutic Drift
Therapeutic drift isn’t usually a single misstep – it’s a series of tiny detours. The antidote is a mix of structure, reflection, and deliberate practice.
Anchor to the Model (without becoming rigid)
Name the core mechanisms for the treatment you’re using (e.g., in CPT: identifying stuck points, Socratic questioning, challenging maladaptive beliefs, written work). Protect these non-negotiables.
Plan fidelity-consistent adaptations up front: cultural wording changes, slower pacing, or longer sessions where clinically indicated (e.g., 90 minutes for clients with English as a second language).
Avoid fidelity-inconsistent changes: skipping modules, blending unrelated techniques, or dropping psychoeducation. If you must deviate, document why, how, and for how long, and set a return point.
Keep sessions purposeful
Start with a micro-agenda: goal for today, link to the case formulation, and the homework bridge (“What did we learn last time, what did you try, what’s the focus today?”).
Use a brief outcome check-in each session (symptoms, functioning, belief ratings) to steer decisions by data, not drift.
Close with a wrap and task: what changed today, what’s the between-session practice, how will we know it helped?
Revisit the case formulation when progress stalls
If change is flat by session 3-4, don’t swap models; re-examine the formulation: is the target problem clear, are stuck points precise, is avoidance blocking work, are tasks matched to capacity?
Collaboratively recommit to the rationale: “Here’s why this step matters for your goals.”
Use measurement to counter intuition creep
Brief standardised measures (symptoms, mood, avoidance, belief strength) before each session or weekly.
Track trends visually. If outcomes dip after an adaptation, course-correct toward the protocol.
Supervision and peer consultation (make it active)
Bring audio or session notes, highlight exact decision points (“I skipped the worksheet because…”) and invite alternatives.
Deliberate practice: rehearse a 5-minute drill on Socratic questioning or stuck-point work; get feedback; try again.
If delivering CPT for PTSD, consider LoSavio et al.’s therapist “stuck points” questionnaire to identify personal barriers and track change across training.
Work with your own emotions, not around them
Notice therapist thoughts like “If I push, I’ll harm them” (Meehl’s spun-glass concern). Treat these as therapist-side safety behaviours.
Use brief self-supervision prompts:
What am I avoiding right now?
What does the model suggest I do next?
How can I pursue this kindly but firmly?
Handle supportive-counselling detours
Validate and link the story to the target mechanism: “Your week with your brother hits the belief ‘I’m unsafe’. Let’s map that belief and test it.”
End each narrative segment with a task or experiment tied to the model.
Prioritise when multiple issues crowd the room
Agree on a sequenced plan: primary target → secondary targets. Explain the functional logic: “If we reduce PTSD avoidance first, relationship skills will land better.”
Park non-primary items in a “later work” list so they feel held, not ignored.
Navigate system pressures without losing fidelity
If session numbers are capped (e.g., funding or policy limits), front-load core components, tighten agendas, and guard key worksheets/skills.
Use between-session work (readings, written tasks, behavioural experiments) to maintain momentum without cutting crucial steps.
Document decisions and make drift visible
After each session, jot two lines: What fidelity-critical element did I deliver? / What adaptation did I make and why?
Review these notes fortnightly with a peer to spot creeping patterns early.
Therapeutic drift is rarely intentional, but it can quietly erode the potency of evidence-based care
By protecting core mechanisms, making purposeful adaptations, measuring outcomes, and engaging in active supervision, therapists can stay faithful to the treatment’s design and responsive to the person in front of them. The research is clear: fidelity (paired with a strong alliance) drives better outcomes. The practical path there is structure, reflection, and small, consistent course corrections.
References
Basten, C. (2019). The Art of CBT: Individualised Strategies to Respond to Common Obstacles in Therapy. Sydney: Australian Academic Press.
Corvalan, J. C., & Klein, D. (2011). PTSD: diagnosis, evolution, and treatment of combat-related psychological/psychiatric injury. Missouri Medicine, 108(4), 296–303.
Farmer, C. C., Mitchell, K. S., Parker-Guilbert, K., & Galovski, T. E. (2017). Fidelity to the Cognitive Processing Therapy Protocol: Evaluation of Critical Elements. Behaviour Therapy, 48(2), 195–206. https://doi.org/10.1016/j.beth.2016.02.009
Grove, W. M., Zald, D. H., Lebow, B. S., Snitz, B. E., & Nelson, C. (2000). Clinical versus mechanical prediction: a meta-analysis. Psychological Assessment, 12(1), 19–30. https://doi.org/10.1037/1040-3590.12.1.19
Holder, N., Holliday, R., Williams, R., Mullen, K., & Surís, A. (2018). A preliminary examination of the role of psychotherapist fidelity on outcomes of cognitive processing therapy during an RCT for military sexual trauma-related PTSD. Cognitive Behaviour Therapy, 47(1), 76–89. https://doi.org/10.1080/16506073.2017.1357750
Keefe, J. R., Hernandez, S., Johanek, C., Landy, M. S. H., Sijercic, I., Shnaider, P., Wagner, A. C., Lane, J. E. M., Monson, C. M., & Stirman, S. W. (2022). Competence in Delivering Cognitive Processing Therapy and the Therapeutic Alliance Both Predict PTSD Symptom Outcomes. Behaviour Therapy, 53(5), 763–775. https://doi.org/10.1016/j.beth.2021.12.003
LoSavio, S. T., Dillon, K. H., Murphy, R. A., & Resick, P. A. (2019). Therapist stuck points during training in cognitive processing therapy: Changes over time and associations with training outcomes. Professional Psychology: Research and Practice. Advance online publication. https://doi.org/10.1037/pro0000253
Marques, L., Valentine, S. E., Kaysen, D., Mackintosh, M. A., Dixon De Silva, L. E., Ahles, E. M., Youn, S. J., Shtasel, D. L., Simon, N. M., & Wiltsey-Stirman, S. (2019). Provider fidelity and modifications to cognitive processing therapy in a diverse community health clinic: Associations with clinical change. Journal of Consulting and Clinical Psychology, 87(4), 357–369. https://doi.org/10.1037/ccp0000384
Meehl, P. E. (1973). Why I do not attend case conferences. In P. E. Meehl: Psychodiagnosis: Selected papers (pp. 225–302). Minneapolis: University of Minnesota Press.
Waller, G., & Turner, H. (2016). Therapist drift redux: Why well-meaning clinicians fail to deliver evidence-based therapy, and how to get back on track. Behaviour Research and Therapy, 77, 129–137. https://doi.org/10.1016/j.brat.2015.12.005
