Have you ever tried to learn a new skill?
Think about the last time you tried to learn something new.
Maybe it was painting, tennis, a language, or a musical instrument.
Classes to learn a skill don’t meet once or twice. They’re usually structured as 10–12 weekly sessions, because real learning takes repetition, feedback, and time. Building a new skill—or changing a habit—doesn’t happen in a few afternoons.
So it raises an important question:
Why would we expect to change the way we relate to our thoughts and emotions, overcome trauma, or transform long-standing relationship patterns, in fewer than eight hours?
Therapy isn’t just a conversation. It’s a skill-building process that unfolds over time. Clients learn how to notice patterns, respond differently under stress, practice new ways of relating, and integrate those changes into everyday life. Just like learning any other complex skill, this process requires consistency and enough time for the work to actually take hold.
This intuitive idea is also strongly supported by decades of psychotherapy research.
Therapy Works Over Time, Not All at Once
Psychotherapy researchers often describe treatment in terms of dose–response: the relationship between the number of sessions (the “dose”) and clinical improvement (the “response”).
One of the most influential studies in this area, conducted by Howard and colleagues (1986), demonstrated that while some symptom relief can occur early in treatment, actual sustained gains typically unfold after a greater number of sessions. Subsequent research confirmed this pattern across real-world outpatient settings, showing that early improvement and lasting change are not the same thing (Hansen, Lambert, & Forman, 2002; 2003).
The American Psychological Association summarizes this body of research by noting that most evidence-based psychotherapies are commonly delivered over 12–20 sessions, with shorter treatment often insufficient for lasting gains.
Why Eight Sessions Matters Clinically
Eight sessions does not represent a full course of therapy for most clients. Rather, research suggests it may be the minimum number of sessions needed to allow therapy to work as intended.
Within the first several sessions, clients and therapists typically:
Build a therapeutic relationship
Clarify goals and expectations
Identify patterns that maintain distress
Begin learning and practicing new skills
As therapy continues, clients have time to:
Apply these skills in real life
Encounter setbacks or challenges and work to course correct
Repair misunderstandings or ruptures in the therapeutic relationship that often mirror relationships outside of the therapy space
Evaluate progress and uncover additional areas that need to be addressed beyond the client’s initial stated goals
Research on psychotherapy retention shows that ending therapy early is common and is associated with poorer outcomes, even when clients experience initial relief (Swift & Greenberg, 2012). Staying engaged long enough for the process to unfold is a key part of effective care.
What the Research Shows Across Conditions
Depression
Clinical trials for depression routinely evaluate therapies delivered over 12–16 or more sessions, including cognitive-behavioral therapy and short-term psychodynamic therapy. These structured courses reflect standard outpatient practice and the time needed to consolidate meaningful emotional and behavioral change.
Anxiety Disorders
For conditions such as generalized anxiety disorder and panic disorder, research includes both standard-length and brief cognitive-behavioral models. Even in brief formats, treatment is delivered as a complete multi-session intervention, typically spanning at least 10-12 weeks rather than one-off visits.
Trauma and PTSD
Guidelines from the American Psychological Association show that evidence-based trauma treatments are designed with clear session ranges, including:
Cognitive Processing Therapy: 12–17 sessions
Cognitive Therapy: 9–16 sessions
Trauma-focused CBT: commonly 12–16 sessions
Dialectical Behavioral Therapy: 48 sessions at minimum
These approaches rely on gradual, cumulative work that cannot be meaningfully compressed into just a few sessions.
Couples Therapy
Research on Emotionally Focused Therapy for couples includes randomized controlled trials using 8-session structured models, with many couples continuing beyond that depending on the complexity of their concerns. Relationship change, like individual change, develops through repeated experiences and practice over time.
Client Engagement Is a Key Part of Client Success
Multiple meta-analyses show that a strong therapeutic alliance—developed and strengthened over time—is associated with lower dropout and better outcomes (Sharf, Primavera, & Diener, 2010). Therapy works best when clients are able to stay engaged long enough to fully benefit from the process.
Not every client needs the same total number of therapy sessions. Some reach their goals within the early phase of treatment, while others benefit from continued work over a longer period of time. At PracticeVital, we support flexibility in care by allowing practices to tailor treatment length based on clinical modality and the goals they have for client care, with eight sessions serving as a thoughtful starting point rather than a fixed endpoint.
Therapy takes time—not because change is out of reach, but because meaningful change is complex, relational, and built through repeated practice over time.