Originating from life span psychology, there is for decades extensive research on wisdom psychology (Grossmann, 2021, Dong et al., 2023). In the “Berlin wisdom paradigm” (Baltes & Staudinger, 2000) wisdom has been defined as “expertise in the conduct and meaning of life and a key factor in the construction of a good life”. The consensus across all researchers is that wisdom skills are essential for guiding life under a long-term perspective, for mastering difficult situations and dilemmas in life, and for “solving unsolvable problems” (Linden, 2023). This includes irreversible dilemmas like death or infidelity of a partner, and ambiguous dilemmas like deciding whether to stay with the sick child at home or to go to work, or even daily trivialities like buying either bio- or no-name orange juice, which nevertheless requires decisions on opposing aspects like money, health, the environment, wishes of others etc.

Different researchers on wisdom have emphasized different, but also similar and related subdimensions of wisdom. Jeste et al., (2019, p. 1) summarizes the state of research by writing: “While there are different conceptualizations of wisdom, it is best defined as a complex human characteristic or trait with specific components: social decision making, emotional regulation, prosocial behavior (such as empathy and compassion), self-reflection, acceptance of uncertainty, decisiveness, and spirituality”. There is empirical evidence that wisdom is a resilience factor in burdening situations and that wise people can better draw lessons from the past and look forward, show proactive problem solving, have empathy with other persons, can cope with difficult situations in life and have a better mastery of life (Bechara et al., 2021). The degree of personal wisdom is more important for well-being than material goods or health (Ardelt & Jeste, 2018). “Wisdom is associated with positive life outcomes including better health, well-being, happiness, life satisfaction, and resilience” (Jeste et al., 2019, p. 1).

An important question is whether wisdom is an unchangeable personality trait or whether it can at least to some degree be modified. A systematic review of randomized trials on the training of wisdom summarizes studies on emotion regulation, mindfulness, and spiritual care, which are somewhat related to wisdom, but not wisdom as such (Lee et al., 2020). Still, these studies suggest that there are ways to enhance wisdom skills.

Given this background wisdom psychotherapy was developed as a mode of cognitive behavior therapy (CBT). Wisdom attitudes were translated into wisdom capacities and skills, which can help to deal with difficult problems in life (Linden et al., 2023). These are: knowledge of facts and problem-solving, contextualism, value relativism, change of perspective, compassion and emotional empathy, self-distance, self-relativization and modesty, recognition, acceptance and control of emotions, humor, long-term perspective, distance from the past and forgiveness, and uncertainty intolerance. A specific approach is the technique of unsolvable life problems, which works with fictitious problems, refering to the “Solomon’s paradox”, as it is easier to give advice to others than oneself (Grossmann & Kross, 2014). Patients are encouraged to discuss what can be done to get the best out of the situation or what to do, to make everything worse. Patients are taught to note facts and reality, change of perspective, uncertainty tolerance, value relativism etc. Patients learn wisdom skills and strategies in a rather playful way, instead of immersing in their own misery. Goal is not to help patients solve their problems, but to teach how to cope with complex life situations in general. Goal is not “hedonic” but rather “eudaimonic well-being”, which is about living in a decent way, to deal functionally with challenges in life, and to do what can be considered right, even at the cost of subjective suffering (Linden, 2024).

Study hypothesis

Goal of the present study was to test in a randomized controlled trial whether wisdom psychotherapy can increase wisdom skills. An auxiliary study question was, to what degree this may also improve other clinical parameters.

Setting and patients

The study was done in a psychosomatic hospital (Heinrich Heine Rehabilitation Centre Potdam, Germany, Linden 2014).

Patients are admitted on their own initiative, but also send in by health and pension insurance, when their ability to work is endangered and early retirement may be pending. Patients are suffering from all types of mental disorders, predominantly affective disorders, anxiety disorders, and personality disorders. Inpatient treatment lasts about five weeks, including medical and medication treatment, weekly one individual and three group psychotherapy sessions, occupational therapy, sport therapy, social counselling, and work-related support. There are additional special group treatments according to individual needs of patients.

Study interventions

In addition to this intensive and comprehensive regular treatment, wisdom group psychotherapy and behavioral activation group therapy was offered. There were three sessions per week, which allowed for 10 treatment sessions during the inpatient stay. New patients were continuously admitted and others discharged from the groups.

The basics of wisdom psychotherapy (WT) have already been described above. In the study we followed a manual for “Wisdom Group Therapy” (Linden & Mossakowski, 2022).

A group therapy on behavioral activation (BA), following Stein et al. (2021), was used to control for unspecific treatment factors. Patients were not encouraged to increase their present level of activities but, it was only discussed what they possibly could do after discharge from the hospital. There was no discussion of patient problems.

Referring to routine data from the hospital, it was possible to select an additional control group of patients who had not participated in the study. These patients were selected in comparison to the patients in the wisdom group by propensity score matching, using the “nearest neighbor procedure” (Benedetto et al., 2018). This group serves to control for unspecific effects of the study procedures.

Therapists

Both group treatments were done by the same two therapists, who were state licensed psychotherapists, educated in cognitive behavior therapy. One was male (39 years, 7 years working as clinical therapist), the other female (50 years, 19 years working as clinical therapist). They were specifically trained and supervised by the first author on a regular basis.

Instruments

Sociodemographic data: Sociodemographic data and clinical diagnoses were taken from the hospital patient files.

ADNM8: The ADNM8 scale (Adjustment Disorder New Module-Scale) is a self-rating instrument with eight items rcovering diagnostic criteria for adjustment disorder according to the DSM-5 (Kazlauskas et al., 2018). Rating options are 1 = never, 2 = rare, 3 = sometimes, 4 = often. The authors recommend a threshold for adjustment disorders of 18.5 and higher.

Embitterment: Embitterment is a burning emotion in the context of negative life events. Since wisdom therapy was originally developed with reference to embitterment, we included two items from the PTED self-rating scale (Linden et al., 2009a, 2009b): “When I think about past events, I experience feelings of insult, injustice and bitterness” and “When I think about past events, I feel a need for retribution”, with a rating from 1 = never, to 4 = often. A sum score of 5 and above indicates a clinically relevant level of embitterment.

Standardized diagnostic interview on PTED: A standardized diagnostic interview for posttraumatic embitterment disorder (PTED) was done in both intervention groups (Linden et al., 2008).

SCL-90: To measure general psychological distress and subjective hedonic well-being, the “Symptom Checklist-90 (SCL-90)” (Franke, 2014) was used. The scale lists 90 unspecific complaints (e.g. nervousness, feelings of loneliness), which are answered on a five-point Likert scale from 0 = not at all to 4 = very strong. A Global Severity Index (GSI) above 0.7 indicates psychological problems. This scale was filled in routinely by all patients of the hospital at admission and before discharge, including all study patients and the routine control.

BDI: The Beck Depression Scale (BDI) is a 21-item self-rating scale measuring mood impairment by asking for negative mood, pessimism, self-reproaches, incapacity, tiredness, worrying, and others (Beck et al., 1996). Ratings go from 0 = no problem to 3 = severe problem. A sum score above 14 indicates mild, above 20 moderate, and above 29 severe depression.

DLB: As measure for burdens in life the “Differential Life Burden Questionnaire (DLB)” was used (Linden & Ritter, 2007). Patients are asked which feelings they have when thinking of seventeen different areas of life (e.g. friends, work, finances, etc.). Ratings are: 0 = very negative, 1 = negative, 2 = slightly negative, 3 = slightly positive, 4 = positive, 5 = very positive. A sum score below 50 indicates general stress and burdens in life. Cronbach Alpha in our study has been 0.86 pre and 0.86 post.

RADL: As the control group treatment tried to support recreational activities, patients were asked to answer a modified version of the RADL scale (Recreational Activities of Daily Living, Linden et al., 2009b) which lists activities such as social encounters, television, relaxation, cooking, excursions, music, hobbies, wellness, reading, sport, nature, and culture. Patients are asked to evaluate whether they “deliberately do or plan to do this activity to feel better”. We counted patients who initially did not, but before discharge did affirm this statement in regard to single activities. Cronbach Alpha in our study has been 0.77 pre and 0.78 post.

MWC-15 scale: The pivotal instrument of the study was the “Multidimensional Wisdom Competency Scale (MWC-15)”, a modification of earlier versions (Schrader & Muschalla, 2022). The scale has 15 items, each addressing one wisdom domain. The focus is not on wisdom attitudes or what people believe and agree with, but rather wisdom skills or what they do when confronted with problems. The initial statement reads: “Persons react differently to burdens, problems, or dilemmas in life. Please indicate to what degree the following statements describe how you react in daily life. This is followed by “When I am confronted with a problem or dilemma in life” (1) “I take my time to check what exactly happened” (knowledge of facts), (2) “I look what alternative solutions are at my disposition” (knowledge of procedures), (3) “I accept that the context is as it is and can often not be changed” (contextualism), (4) “I am aware that there are always many views on the same situation” (value relativism), (5) “I first of all try to understand why everybody has acted as they did” (change of perspective), (6) “I try to feel what emotions all others have in this situation” (emotional empathy), (7) “I am aware that everything could be much worse” (acceptance of facts), (8) “I try to be content with what I still have” (modesty), (9) “I accept that I have negative or even undesirable feelings” (acceptance of emotions), (10) “I first of all try to calm down and control my emotions” (serenity), (11) “I am aware that humor means to laugh nevertheless” (humor and relativization of problems), (12) “I avoid to reheat old stories and events” (distance from the past and forgiveness), (13) “I accept that many things cannot be changed” (uncertainty tolerance), (14) “I always see the chances which come out of problems” (optimism), (15) “I know that time is a great healer” (long term perspective). The rating is made on a Likert scale from 0 = no, 1 = hardly true, 2 = somewhat true, 3 = mostly true, to 4 = definitely true. A score below 2.5 is suspicious of wisdom deficits. The MWC-15 scale was also part of the routine assessment in the hospital at admission and before discharge and is therefore available for the two study groups and the routine control group. Cronbach Alpha in our study has been 0.80 pre, and 0.89 post.

UE-ATR-G: Monitoring of side effects was done with the “Unwanted Events and Adverse Therapy Responses in Groups (UE-ATR-G)” (Muschalla et al., 2020). It asks for treatment related burdens in relation to the room, the group content, the other participants, the therapist, and the general group experience. Ratings are: 1 = does not apply, 2 = somewhat true, 3 = partially true, 4 = mostly true, 5 = completely true.

Protocol adherence

Protocol adherence of the therapists was controlled with the “treatment protocol adherence checklist for patients (TPA-P)”. This is constructed according to the pivotal topic method (Linden et al., 2005). Patients are asked to indicate whether a topic had been addressed during group therapy. Items are for example: “We discussed that one should not look back but to the future” (wisdom), or “We discussed that it is important to be active” (behavioral activation). This reflects what patients had experienced during the group sessions, independent of what therapists intended to do. The TPA-P has ten items describing contents of wisdom therapy and another ten for behavioral activation.

Procedures

All new patients were seen by a senior psychiatrist after admission to the hospital, according to clinical routines. They routinely filled in several rating scales. If the score on the ADNM8 was above 18 and the senior psychiatrist did not see any contraindication, patients were contacted by the researchers. After giving their consent to participate, they were randomly assigned to wisdom psychotherapy (WT) or the behavioral activation group (BA). Patients filled in the scales during routine assessment after hospital admission, at the beginning, and end of the study period.

Follow Up

Patients who allowed to be contacted again, were send a letter half a year later and asked to fill in the MWC-15 scale, ADNM8, and embitterment scale once more.

Statistics

In comparing sociodemographic characteristics between groups, T-tests and Chi²-tests were calculated.

The study followed a 2 × 3 or 3 × 3 design with two intervention groups and the routine group on one hand and pre-, post-, and follow-up assessments on the other. The research question is not to test for pre-post differences, as these are expected because of time, repeated measurement, and because all patients underwent a comprehensive clinical inpatient treatment of five weeks. The research question has been tested by a mixed ANCOVA, which is calculated for pre, post, and follow up comparisons and tests time by group interactions (Read et al., 2013).

Informed Consent

All patients were informed in advance about the study in writing and in person by researchers. They gave their written informed consent and agreed to participate and accept randomization prior to the study participation.

We approached 235 patients and 223 agreed to participate in the study, of whom 114 were allocated to wisdom therapy (WT), with 23 dropouts during treatment, and 109 to the behavioral activation group (BA) with 29 dropouts. As a further control group, 114 patients were selected by propensity matching from patients who got routine inpatient treatment (RT) only. In the WT, 88.0% of patients allowed to contact them again after discharge from the hospital, of which 58.0% send back the questionnaires, accounting for 41.2% of all wisdom patients. In the BA group, 90.0% allowed to be contacted, of which 62.5% answered, representing 39.5% of all BA patients. There is no significant difference.

Three quarters of patients were female. The mean age was 53 years, about 30% had at least a high school education, and about half were married. Patients were on average 35 days in the hospital. Clinical diagnoses, which were given by the treating physicians at discharge, were affective disorders in about 80% of cases. There were 5% (WT) and 8% (BA) of patients suffering from “Posttraumatic Embitterment Disorder” according to the standardized interview. There were on average 10 sessions of WT and BA. There were no significnt differences between the study groups in any of these variables.

Initial baseline scores of the ADNM8 was 27, which is in line with the inclusion criteria, and much above the threshold of 18.5, indicating adjustment problems (see Table 1). Similarly, the DLB scores were about 47, which is below 51, indicating relevant stress across many areas in life. The SCL scores were 1.2, which is greatly above 0.7, speaking for increased subjective psychological distress. The BDI scores were about 25, which is much above 20 in the range of clinically relevant depressed mood. The embitterment scores were close to the threshold of 5. This indicates that embitterment is not the primary problem in these patients, while they are otherwise obviously burdened and distressed in a clinically relevant level. Patient ratings on the protocol adherence checklist (TPA-P) showed highly significant and meaningful differences between groups, confirming that therapists, who conducted both groups, were able to apply different interventions according to the manuals.

Table 1 shows the results for the MWC-15 scale. Mixed ANCOVA with repeated measurements yielded a statistically significant time by group interaction (F(2, 253) = 5.79, p = 0.003, partial η² = 0.05), speaking for a greater increase in the wisdom group as compared to both control groups. For patients with follow-up data, a significant time by group interaction was found as well (F(1, 90) = 4.08, p = 0.04; partial η² = 0.04), suggesting that the treatment effects lasted beyond the inpatient stay.

The SCL-90 GSI total score decreased 0.39 points in the wisdom group, 0.33 in the activity group, and 0.34 in the routine group, which is a statistically significant and also clinically relevant decrease in the overall distress but without a significant time x group interaction. Similarly, there was a decline in the BDI score of 9 points in the wisdom an 8 in the activity group, a significant decrease over time and a trend in favor of the wisdom group in the time/group interaction. The ADNM8 score decreased 3.8 points in the wisdom and in the activity group, which is also a significant and clinically relevant decrease over time, but no time/group interaction. The two-item embitterment rating decreased 0.89 points in the wisdom group and 0.58 in the activity group, with a trend in favor of the wisdom group. The DLB improved by 6.1 points in the wisdom and 6.8 in the activity group which is significant over time with no significant time/group interaction. The RADL score increased 5 points in the wisdom group an 7 points in the activity groups, which no significant difference. The sum score of the UE-ATR-G scale was somewhat higher in the wisdom than the activity group, though not statistically significant.

This is to our knowledge the first study which explicitly tests whether wisdom skills can be improved by wisdom psychotherapy in patients with mental disorders. Quality aspects of the study are (a) that wisdom skills are specifically targeted, (b) that the study was done in a transdiagnostic sample of patients suffering from persisting negative life events, (c) that there was an “active placebo control” in the form of behavioral activation controlling for unspecific effects of group treatment, (d) that there was a second control group of patients, coming from routine treatment, controlling for unspecific effects of the study procedures, (e) that there was a sufficiently large number of patients, (f) that the treatment was done by two experienced psychotherapists, who did both groups, controlling for individual therapist factors, (g) that therapist protocol adherence was empirically tested, and (h) that patients were routinely treated as inpatients with individual and group psychotherapy, medical and medication treatment, occupational and sport therapy, social care and others, so that the effects of wisdom therapy can be distinguished from effects of unspecific patient care. (i) The study was done with patients showing an elevated score in the ADNM8, which is indicative of adjustment problems and who were suffering from relevant mental disorders and problems, as shown by other clinical measures. (j) The study also looked for side effects of treatments, and (j) we could get follow-up information half a year later.

The hypothesis of the study has been that wisdom therapy can increase wisdom skills as measured with the Multidimensional Wisdom Competency Scale (MWC-15). The results support this expectation and related studies from other researchers (Ferrari & Potworowski, 2008; Grossmann et al., 2021; Sternberg et al., 2008; Bruya & Ardelt, 2018; Barrientos-Rastrojo & Gómez-Bujedo, 2019; Lee et al., 2020; Kurd Noqabi & Asoodeh, 2021; Kallio & Tynjälä, 2025). There is an increase in the wisdom score in patients in the wisdom therapy group as compared to those in the activation group or the matched patients who have not participated in the study. There is a statistically significant time x group interaction for the MWC-15 score. The results can be attributed to wisdom therapy because of the “wisdom-placebo-controls” in the form of BA and RT. Our results confirm other scientific reports, which suggest that wisdom can be trained.

There are only to a limited degree changes in other clinical measures of well-being. This is characteristic for wisdom therapy. Phenomenological and performative approaches to conceptualizing and measuring wisdom are first of all correlated with eudaimonic wellbeing (Dong et al., 2023). Eudaimonia describes how to live a decent and socially responsible life, even at the cost of accepting hardship, such as a mother who cares about the crying baby at night altough this is burdensome. She feels hedonically bad, but eudaimonically good. Training of wisdom can therefore not be expected to improve “hedonic” wellbeing but rater mastery of life (Linden, 2024). Still there are trends for the ADNM8, BDI, and embitterment in favor of the wisdom psychotherapy group.

The assessment of side effects shows a trend for more side effects in WT than BA. This is plausible as in the activity group only pleasurable topics and activities were discussed. In the wisdom group, on the contrary, problem solving was the topic.

Apart from the primary goal of our study, an important subsidiary result is to show that therapists can perform different types of treatment in compliance with treatment manuals, instead of only following their idiosyncratic therapeutic preferences, or referring to the therapeutic relation and common factors in general (Villiger, 2025), and that this produces different outcomes.

Limitations of the present study are that it was done in the context of a comprehensive inpatient treatment, which may have clouded effects of wisdom psychotherapy on the clinical status of patients. In a next step, separate controlled trials are needed. The possibilities for follow-up were limited, so that more detailed follow-up investigations are needed to learn how wisdom therapy may influence the further course of life.

Clinical Applications

In summary, the data suggest that wisdom competencies can be trained and enhanced by structured treatment. As wisdom is known to help persons not only to master their life in general but also to cope with adversities in life, wisdom should have a greater role in psychotherapy.