The Psychotherapy Practice Research Network (PPRNet) blog began in 2013 in response to psychotherapy clinicians, researchers, and educators who expressed interest in receiving regular information about current practice-oriented psychotherapy research. It offers a monthly summary of two or three published psychotherapy research articles. Each summary is authored by Dr. Tasca and highlights practice implications of selected articles. Past blogs are available in the archives. This content is only available in English.
…I blog about transtheoretical principles of change, microaggressions and outcomes, interpretations and outcomes.
Type of Research
- ALL Topics (clear)
- Alliance and Therapeutic Relationship
- Anxiety Disorders
- Attendance, Attrition, and Drop-Out
- Client Factors
- Client Preferences
- Cognitive Therapy (CT) and Cognitive-Behavioural Therapy (CBT)
- Combination Therapy
- Common Factors
- Depression and Depressive Symptoms
- Efficacy of Treatments
- Feedback and Progress Monitoring
- Group Psychotherapy
- Illness and Medical Comorbidities
- Interpersonal Psychotherapy (IPT)
- Long-term Outcomes
- Neuroscience and Brain
- Outcomes and Deterioration
- Personality Disorders
- Placebo Effect
- Practice-Based Research and Practice Research Networks
- Psychodynamic Therapy (PDT)
- Resistance and Reactance
- Self-Reflection and Awareness
- Suicide and Crisis Intervention
- Therapist Factors
- Transference and Countertransference
- Trauma and/or PTSD
- Treatment Length and Frequency
What Proportion of Patients Benefit from Short-Term Psychotherapy?
Cuijpers, P., Karyotaki, E., Ciharova, M., Miguel, C., Hisashi, N., &Furukawa, T.A. (2021). The effects of psychotherapies for depression on response, remission, reliable change, and deterioration: A meta-analysis. Acta Psychiatrica Scandinavica, 10.1111/acps.13335. Advance online publication.
Many meta-analyses report that psychological therapies are effective to treat depression, that there are no differences between types or orientations of therapy in their outcomes, and that psychotherapy is as effective as medications in the short term and perhaps more effective in the longer term. But what do these findings mean for everyday practice? Many meta-analyses report a standardized mean effect size between treatment and control conditions. However, the effect size is an abstraction that may be difficult to interpret unless you understand the statistic. Clinicians may ask a more practical question: what is the proportion of patients that improve (have meaningful reductions in depression scores) and recover (improved and no longer are depressed)? This meta-analysis by Cuijpers and colleagues of 228 studies representing over 23,000 adult patients looked at the proportion of patients who improved and recovered after psychotherapy relative to those in control conditions (no treatment, care as usual, pill placebo). The psychotherapies were short term manualized treatments like CBT, behavioral activation, interpersonal psychotherapy delivered in individual, group, and self-help formats. About 41% of patients improved with psychotherapy for depression compared to 17% that improved with usual care and 31% for pill placebo. However, after statistically controlling for publication bias (i.e., the likelihood that some unflattering studies were never published), the improvement rate for psychotherapy was 38%. Recovery rates for psychotherapy ranged from 26% to 34%, and recovery in the control conditions ranged from 9% to 17%. There were no differences between therapy orientations. Highest rates of recovery or improvement were achieved by individual therapy and the lowest rates were seen in guided self-help. Deterioration rates were just below 5% in psychotherapy and about 7% to 13% in control conditions.
The effects of time-limited manualized psychotherapies tested in randomized controlled trials were modest. About 40% of patients improved and about 30% recovered. On the positive side, psychotherapies resulted in only about 5% of patients getting worse. The authors argued that clinicians must consider more effective strategies beyond these approaches to improve outcomes for depression. Some have focused on improving psychotherapist effectiveness, rather than on specific interventions. Methods like progress monitoring, managing countertransference, and repairing therapeutic alliance ruptures are means of improving psychotherapists’ effectiveness.
How Much Psychotherapy is Really Necessary for Clients to Improve?
Nordmo, M., Monsen, J.T., Høglend, P.A., & Solbakken, O.A. (2020) Investigating the dose–response effect in open-ended psychotherapy. Psychotherapy Research
Findings form psychotherapy research studies have tested a dose-response relationship that shows that after a certain number of sessions the rate of client improvement diminishes. That research tends to show a range of 4 to 12 sessions is necessary in order for the average client to improve (half of clients get better by this point, but half do not yet get better). The key limitation of this research is that the vast majority of it was conducted in student counselling centres offering brief treatments. That is, the clients in this research domain tend to be students with mildly to moderately severe problems, and the counselling centres often had a policy (not based on client need) that limited the number of treatment sessions. There is actually very little psychotherapy dose-response research of clients with moderate to severe problems who receive treatment in naturalistic settings that do not arbitrarily impose a session limit. In such settings, it would be the client’s optimal response to treatment and not externally imposed limits that determine when therapy is terminated. This study by Nordmo and colleagues was conducted in several psychotherapy outpatient clinics in Norway. The 362 adult clients had moderate to severe levels of mental health problems, and about half had a personality disorder. The 88 therapists had about 10 years of experience and used several major orientations of psychotherapy practice (psychodynamic, CBT, behavioral, humanistic). Clinicians and clients came to an agreement about when to terminate therapy, and so no limit on sessions was externally imposed. Outcomes were assessed regularly and were evaluated for reliable change and clinical recovery in symptoms and interpersonal problems. Clients attended an average of 52 sessions (SD = 59, Mdn = 36), and improvements were maintained up to 2 years post-treatment. The results indicated that the more sessions a client received the greater their improvement. This was particularly true for those clients with more severe problems. Clients with less severe problems needed fewer sessions to improve. The average client needed 57 sessions to show clinically significant improvement.
The psychotherapy dose-response research to date is limited because it is primarily based on clients with mild to moderate problems treated in student counselling centres. In real-world contexts, client rate and magnitude of change are related to the length of treatment. That is, clients with moderate to severe problems will require more than 4 to 12 sessions in order to improve. As the authors argued, the one-size-fits-all approach to treatment length in everyday practice is not supported by the research, and does not provide adequate treatment to those clients with moderate to severe problems, or those with complex comorbidities.
Is Short-Term Prolonged Exposure Effective to Treat PTSD in Military Personnel?
Foa, E., McLean, C.P., Zang, Y., Rosenfield, D., Yadin, E… Peterson, A. (2018). Effect of prolonged exposure therapy delivered over 2 weeks vs 8 weeks vs present-centered therapy on PTSD symptom severity in military personnel: A randomized clinical trial. Journal of the American Medical Association, 319, 354-364.
Post-traumatic stress disorder (PTSD) can affect 10% to 20% of military personnel returning from combat. PTSD is often chronic and debilitating, and is associated with symptoms that are distressing, that lower quality of life, and that negatively impact family and loved ones. Prolonged exposure therapy (PE) has been tested in the past, and researchers have claimed that it is an efficacious treatment in civilians and veterans. PE is a form of behavior therapy and cognitive behavioral therapy characterized by re-experiencing the most traumatic event through remembering it and engaging with, rather than avoiding reminders of the trauma. In their treatment guidelines, the American Psychological Association (APA) proposed PE as a recommended treatment for PTSD. In this randomized controlled trial, Foa and colleagues assess if providing PE in intensive short time frame (massed exposure; 10 sessions over 2 weeks) was as effective as standard exposure (10 sessions over 8 weeks) for 370 military personnel in the US with PTSD. That is, the authors were interested to see if providing the same amount of therapy based on exposure in a shorter time was just as effective. They also compared the two versions of PE (massed and standard exposure) to two control conditions: present centred therapy (PCT) that is largely supportive therapy that does not rely on exposure to the trauma, and a no treatment control condition. The main outcomes were reductions in level of PTSD symptoms and reductions in PTSD diagnoses at post-treatment and up to 6 months post-treatment. Massed and standard PE were equally effective in reducing symptoms and diagnoses of PTSD compared to no treatment. However, PE was not more effective than PCT in reducing symptoms and diagnoses, and PCT was more effective than no treatment. Overall, reductions in PTSD symptoms and reduction in PTSD diagnoses were modest. Drop out rates were high at about 50% for all conditions.
Drop out rates were high and outcomes were modest for these short-term psychological treatments for PTSD in military personnel, such that over 60% still had a diagnosis of PTSD at 6 months follow up. And PE therapy did no better than a control condition (PCT) that simply provided support with no exposure to the trauma. These findings are similar to other research in this area. Psychotherapy for trauma may require more time to work, and perhaps different models of understanding and treating the disorder. As Shedler recently remarked, it takes at least 20 sessions/weeks before 50% of clients improve. So it may not be surprising that 2 or 8 weeks of therapy had only a small impact on PTSD symptoms.
Long Term Psychodynamic Psychotherapy for Treatment Resistant Depression
Fonagy, P., Rost, F., Carlyle, J., McPherson, S.,… Taylor, D. (2015). Pragmatic randomized controlled trial of long-term psychoanalytic psychotherapy for treatment-resistant depression: The Tavistock adult depression study (TADS). World Psychiatry, 14, 312-321.
Usually I do not write about individual studies, mainly because meta-analyses and systematic reviews are much more reliable. But occasionally a unique study is published that is important enough to report. This is a rare trial that focuses on “treatment-resistant” depression defined as long-standing depression that has not responded to at least two previous evidence-based interventions. Depression is known to have a relapsing chronic course for about 12% to 20% of patients. And not responding to treatment is highly predictive of non-response to future treatment for depression. Fonagy and colleagues argued that in order to be effective, treatments for chronic and resistant depression need to be longer and more complex than current time-limited evidence-based approaches. Further, they argued that follow ups should be of longer duration. The authors tested a manualized long term psychoanalytic psychotherapy (LTPP). The treatment involved 60 sessions over 18 months provided by 22 trained therapists. In this trial, the “control” condition was treatment as usual (TAU) as defined by the National Institute for Clinical Excellence in the United Kingdom. TAU was made up of short term evidence-based interventions like antidepressant medications or CBT provided by licensed trained professionals. LTPP plus TAU was compared to TAU alone for 129 patients randomly assigned to one of the conditions. At pre-treatment, the majority of patients scored in the severe range on the Beck Depression Inventory (BDI) or the Hamilton Depression Rating Scale (HDRS). The average patient had 4 previous unsuccessful treatments for depression. No differences were found between LTPP and TAU at post treatment, but differences began to emerge after 24 months. Complete remission was infrequent in both conditions after 42 months (14.9% LTPP vs 4.4% TAU). However, partial remission at 42 months was significantly more likely in LTPP (30.0%) than TAU (4.4%). Patients were significantly more likely not to meet DSM-IV criteria for depression at 42 months in LTPP (44%) than in TAU (10%). The differences between conditions in mean BDI and HDRS scores were significant and medium sized indicating greater improvement with LTPP.
This is the first study of its kind to test a manualized LTPP for treatment resistant depression. Patients in LTPP were more likely to maintain gains whereas those receiving evidence-based TAU were more likely to relapse. Although this is only one study and should be interpreted cautiously, it does suggest that chronic treatment-resistant depression is more likely to respond to longer and more complex treatment, and that outcomes of such treatment tend to be maintained in the longer term.
Does Frequency of Sessions Affect Patient Outcomes?
Erekson, D.M., Lambert, M.J., & Egget, D.L. (2015). The relationship between session frequency and psychotherapy outcome in a naturalistic setting. Journal of Consulting and Clinical Psychology.
The dose-response model of psychotherapy suggests that a single session is like a “dose” of therapy, and that each session adds to a cumulative response by the client. For example, research indicates that between 13 and 18 sessions are required for 50% of patients to improve significantly, but with diminishing returns for clients after 18 sessions. In this very large study in a naturalistic setting, Erekson and colleagues studied the question of the effects of the “dose” or quantity of therapy a little differently. What if the spacing or frequency of sessions rather than the total number of sessions was important to patient outcomes? That is, if psychotherapy reinforces adaptive behaviors, then less learning might occur if time between sessions increases. With greater time between sessions clients may miss timely support from a therapist, and the therapeutic alliance may not be as solid. Erekson examined the impact of session frequency in a very large sample of university students (N = 21,488) seen by therapists (N = 303) for individual therapy lasting about 50 minutes per session. Clients typically received between 6 and 21 weeks of therapy. The data were collected at a counselling center over a 17-year period. Therapist orientations included CBT, psychodynamic, existential, and integrative. Patient outcomes were measured after each session with a reliable measure that allows one to evaluate if a client recovered from symptoms, reliably improved but did not recover, or reliably deteriorated. The authors found that compared to less frequent sessions (approximately every 2 weeks), more frequent sessions (approximately weekly) was associated with faster improvement and faster recovery. The statistical models predicted that 50% of individuals being seen weekly would reliably improve in 8 sessions, whereas 50% those seen every 2 weeks would reliably improve in 12 sessions. That is, clients seen every two weeks required 50% more sessions to achieve the same level of improvement as clients seen every week.
Clients that are seen weekly may have a better therapeutic experience and develop a better therapeutic alliance with their therapists, which may in turn result in faster improvements. More frequent meetings may suggest to clients that their needs are important to the therapist. Institutions may have the opinion that lower session frequency is a way of saving resources, but in the end patients seen less frequently may require more therapy to achieve outcomes at the same rate as patients seen more frequently. Higher frequency of sessions may increase the efficiency of the psychotherapy and possibly reduce the amount of resources invested by the institution to improve patient mental health outcomes.
Does Duration of Therapy Affect Patient Outcomes?
Stiles, W.B., Barkham, M., & Wheeler, S. (2015). Duration of psychological therapy: Relation to recover and improvement rates in UK routine practice. British Journal of Psychiatry, 207, 115-122.
In this very large study from the UK National Health Service (NHS), Stiles and colleagues assessed whether more therapy is better. That is, do people continue to get better with more sessions or do patients reach a certain level of improvement and terminate therapy regardless of number of sessions. The “dose-effect model” of psychotherapy suggests that patients continue to improve with more sessions, although the rate of improvement slows down after 18 sessions. However, large naturalistic studies from the UK health system show that patients have similar rates of recovery regardless of the number of sessions they attend (i.e., up to 20 sessions). These findings suggest that patient improvement may follow a good-enough or “responsive regulation model” of improvement, in which patients responsively regulate the number of sessions that they need. This could have implications for policies regarding how many sessions are prescribed to patients. In this study, Stiles and colleagues drew data from the NHS data base of over 26,000 adult patients who were seen by 1,450 therapists. These were patients who provided enough reliable outcome data, who attended 40 or fewer sessions, and who had a planned ending. Many patients had multiple problems including anxiety, depression, bereavement, and trauma and abuse. Patients who were selected for the study had initial symptom scores in the clinical range. The most common therapy approaches included integrative, psychodynamic, CBT, and supportive. Patient “recovery” was defined as no longer scoring in the clinical range at the end of therapy. Patient “improvement” was defined as a reliable drop in symptom scores on a psychometric measure. Patients received an average of 8.3 sessions, 60% recovered, and an additional 19% improved but did not recover. Rates of reliable improvement were negatively correlated (r = -.58) with number of sessions, and the effect was large. That is, patients who stayed in therapy longer had lower rates of recovery. These patients were more symptomatic at the outset.
The results of this very large naturalistic study suggest that therapists and clients should regularly monitor improvement and adjust the treatment duration based on whether clients improve to a satisfactory level. The authors refer to this as “responsive regulation” of treatment duration. In practice, this means that therapists and clients end treatment when patients have improved to a “good-enough” level, which is likely balanced against costs and alternatives. These findings should encourage therapists and agencies to shift their attention away from prescribing a pre-specified length of treatment at the beginning of therapy towards evaluating on an ongoing basis what constitutes good-enough gains for each client.