Modelling trajectories of change in psychopathology and well-being during eating disorder outpatient treatment.

Objective: There are considerable differences in how eating disorder (ED) patients respond to treatment. This study aimed to identify change trajectories of mental health during treatment. Method: Longitudinal data of 442 patients was used with five time points during a year of outpatient treatment. ED psychopathology and well-being were used as primary measures. A series of latent growth mixture models were applied to model trajectories of change. Results: Three latent classes were found for ED psychopathology and well-being. For ED psychopathology, a high baseline severity and slow recovery class (55.9% of the patients), a high baseline severity followed by a substantial recovery class (19.9%) and a moderate baseline severity and no significant recovery class (24.2%) were found. For well-being, a low baseline followed by a slow growth class (44.6%), a low baseline and substantial growth class (9.5%) and a moderate and stable well-being class (45.9%) was found. General psychopathology, early symptom change, hope for recovery, intrinsic motivation and the ED type were predictive of class membership in either ED psychopathology or well-being. Conclusions: This study shows variability in ED psychopathology and well-being change trajectories, modelled in meaningful latent recovery classes. These results may have clinical implications, such as adjusting patients' treatment based on change trajectories.

Exploring mental health dynamics during eating disorder treatment: A psychometric network study with panel data.

To explore mental health associations during eating disorder (ED) treatment. Based on the dual-continua model of mental health, general and ED-specific psychopathology, as well as emotional, psychological, and social well-being were considered as mental health domains.Network analyses with panel data were applied to explore within- (temporal and contemporaneous networks) and between-person effects in a sample of 1250 female ED patients during 12 months of outpatient treatment. The associations between the domains and their centrality were examined. Autoregressive and cross-lagged effects were also estimated.ED psychopathology was the most central domain in the temporal network. ED psychopathology changes predicted further ED psychopathology changes and small changes in the other domains. Weak bi-directional associations were found between changes in the well-being domains and general psychopathology. In contrast to the temporal network, ED psychopathology was the least central and psychological well-being the most central domain in the contemporaneous and between-subjects networks. This suggests a central role of psychological well-being for experiencing mental health within time points.ED psychopathology may change relatively independent from other mental health domains. Well-being domains may be considered as more stable aspects of mental health.

Exploring associations between personality trait facets and emotional, psychological and social well-being in eating disorder patients.

PURPOSE: Personality functioning is strongly linked to well-being in the general population. Yet, there is a lack of scientific knowledge about the pathways between personality trait facets and emotional, psychological and social well-being in ED patients. The general aim was to examine potential associations between maladaptive personality trait facets and the three main dimensions of well-being. METHODS: Participants were 1187 female eating disorder patients who were referred for specialized treatment. Patients were diagnosed with anorexia nervosa (31.7%), bulimia nervosa (21.7%), binge eating disorder (11%) and other specified eating disorders (35.5%). The Personality Inventory for the DSM 5 (PID-5) was used to measure 25 trait facets, and well-being was measured with the Mental Health Continuum Short Form (MHC-SF). Multiple hierarchical regression analyses were applied to examine potential associations between personality and well-being while controlling for background and illness characteristics. RESULTS: Personality trait facets led to a statistically significant increase of the explained variance in emotional (38%), psychological (39%), and social well-being (26%) in addition to the background and illness characteristics. The personality trait facets anhedonia and depression were strongly associated with all three well-being dimensions. CONCLUSION: Personality traits may play an essential role in the experience of well-being among patients with EDs. To promote overall mental health, it may be critical for clinicians to address relevant personality trait facets, such as anhedonia and depression, associated with well-being in treatment. LEVEL OF EVIDENCE: Level V, cross-sectional descriptive study.

Images of Recovery: A PhotoVoice Study on Visual Narratives of Personal Recovery in Persons with Serious Mental Illness.

Personal recovery has become a guiding paradigm in mental health services. Most research on recovery is based on the exploration of personal stories of service users through verbal methods. As not everyone with psychiatric problems is able to verbally formulate a recovery narrative, the current study assesses personal recovery through PhotoVoice, with emphasis on visualisation, small stories and participation. Two ten-week groups were conducted with 18 participants living with severe mental illnesses. They participated in both the collection and analysis of visual narratives. Across the images produced by participants, four main recovery themes were found : People, Places, Activities and Finding Meaning. Compared to other frameworks, the emphasis participants put on the theme Places adds value to the understanding of recovery processes. Furthermore, participants showed that recovery is about dealing with vulnerabilities as well as aspiring a meaningful life. This study demonstrates that exploring visual narratives is powerful within recovery oriented mental health.

The psychometric network structure of mental health in eating disorder patients.

OBJECTIVE: Psychometric network analysis has led to new possibilities to assess the structure and dynamics of psychiatric disorders. The current study focuses on mental health networks in patients with anorexia nervosa, bulimia nervosa, binge eating disorder and other specified eating disorders (EDs). METHOD: Network analyses were applied with five mental health domains (emotional, psychological and social well-being, and general and specific psychopathology) among 905 ED patients. Also, networks of 36 underlying symptoms related to the domains were estimated. The network stability, structure and (bridge) centrality of the nodes were assessed for the total group and each ED type. Network differences between the ED types were also examined. RESULTS: ED psychopathology was only weakly connected with the well-being domains. Psychological well-being was the most central node in the domain network. The most central nodes in the symptom network were feeling depressed, feeling worthless, purpose in life and self-acceptance. Bridge symptoms between well-being and psychopathology were self-acceptance, environmental mastery, interested in life and feeling depressed. There were no network differences between the ED types in both the domain and symptom networks. CONCLUSIONS: This study shows novel associations between well-being and psychopathology in ED patients. Central domains and their underlying symptoms may be especially important to consider in treatment for promoting mental health in ED patients.

The relationship between depressive symptoms, general psychopathology, and well-being in patients with major depressive disorder.

OBJECTIVE: In mental health care, treatment effects are commonly monitored by symptom severity measures. This study aimed to investigate the relationship between symptom severity and well-being in the treatment of patients with major depressive disorder (MDD). METHODS: Adult MDD outpatients (n = 77) were administered the Quick Inventory of Depressive Symptomatology-Self-Report (QIDS-SR), the Outcome Questionnaire (OQ-45), and the Mental Health Continuum-Short Form (MHC-SF) before treatment and 6 months later. RESULTS: Symptom severity correlated moderately with well-being at baseline and strongly at follow-up. Reliable change index scores showed improvement on the QIDS-SR, OQ-45, and MHC-SF in 65%, 59%, and 40%, respectively. A quarter of patients improved in symptom severity but not well-being (Inventory of Depressive Symptomatology-Self-Report [IDS-SR]: 25%; OQ-45: 24%). CONCLUSION: Findings suggest that symptom severity and subjective well-being are related, but distinct concepts. Several reasons for the stronger improvements in symptoms than in well-being are discussed.

The long and winding road to happiness: A randomized controlled trial and cost-effectiveness analysis of a positive psychology intervention for lonely people with health problems and a low socio-economic status.

BACKGROUND: Our objective was to evaluate the effectiveness and cost-effectiveness of the positive psychology intervention 'Happiness Route' compared to an active control condition in a vulnerable population with an accumulation of health and psychosocial problems. METHODS: We conducted a randomized, single-blind, actively-controlled, parallel group study in seven municipalities in the Netherlands. To be eligible, participants had to experience loneliness, health problems and low socio-economic status. Each group received several home visits by a counsellor (two in the control condition, two to six in the experimental condition). In the Happiness Route, a happiness-based approach was used, whereas the control condition used a traditional problem-based approach. The primary outcome was well-being, measured with the Mental Health Continuum-Short Form (MHC-SF). RESULTS: Fifty-eight participants were randomized to the Happiness Route, 50 to the control condition. Participants were severely lonely, had on average three health problems and less than 5% had paid work. The total MHC-SF score, emotional and social well-being, depression and loneliness improved significantly over the nine-month period in both conditions (p < .05), but there were no significant changes between the conditions across time. Languishing decreased significantly from 33% at baseline to 16% at follow-up among the Happiness Route participants but did not change significantly in the control condition. No significant improvement over time was found in psychological well-being, resilience, purpose in life, health-related quality of life and social participation. Cost-effectiveness analysis showed that expected saved costs per QALY lost was €219,948 for the Happiness Route, relative to the control condition. The probability was 83% that the Happiness Route was cost saving and 54% that the Happiness Route was cost-effective at a willingness to accept a threshold of €100,000. CONCLUSIONS: Mental health status of both groups improved considerably. However, we could not demonstrate that the Happiness Route yielded better health outcomes compared to the control condition. Nevertheless, the results of the cost-effectiveness analysis suggested that the Happiness Route is an acceptable intervention from a health-economic point of view. Our results should be viewed in light of the fact that we could not include the planned number of participants. TRIAL REGISTRATION: Netherlands Trial Register: NTR3377. Registered 2 Apr 2012.

Exploring facilitators and barriers to using a person centered care intervention in a nursing home setting.

Person-centered care (PCC) interventions have the potential to improve resident well-being in nursing homes, but can be difficult to implement. This study investigates perceived facilitators and barriers reported by nursing staff to using a PCC intervention consisting of three components: assessment of resident well-being, planning of well-being support, and behavioral changes in care to support resident well-being. Our explorative mixed method study combined interviews (n = 11) with a longitudinal survey (n = 132) to examine which determinants were most prevalent and predictive for intention to use the intervention and actual implementation 3 months later (n = 63). Results showed that perceived barriers and facilitators were dependent on the components of the intervention. Assessment of resident well-being required a stable nursing home context and a detailed implementation plan, while planning of well-being support was impeded by knowledge. Behavioral changes in nursing care required easy integration in daily caring tasks and social support.

Effectiveness of a life story intervention for adults with intellectual disability and depressive and trauma-related complaints.

INTRODUCTION: People with intellectual disability have a higher chance of developing mental disorders than the general population. Yet, few evidence-based interventions exist. This article evaluates My Lifestory, a narrative intervention tailored to people with intellectual disability and depressive or trauma-related complaints. METHOD: A quasi-experimental research design was adopted with an experimental condition (My Lifestory) and a matched control condition (care as usual). Measurements took place before the intervention, at the end of the intervention and at follow-up two months later. Measurements focused on psychiatric complaints, well-being, life satisfaction, mastery, and purpose in life. RESULTS: Participants in the intervention condition improved more in psychiatric complaints, well-being, life satisfaction, and purpose in life, but not in mastery, than participants in the control condition. Effect sizes were large in the intervention condition and small in the control condition. DISCUSSION: Despite some limitations, this study adds to the evidence base of this narrative intervention.

Life story books for people with dementia: a systematic review.

ABSTRACTObjectives:There is an increasing evidence that reminiscence therapy is effective in improving cognitive functions and reducing depressive symptoms in people with dementia. Life story books (LSBs) are frequently used as a reminiscence tool to support recollecting autobiographical memories. As little is known about how LSBs are used and what type of studies have been employed to evaluate LSB interventions, we conducted a systematic review. METHODS: The electronic databases Scopus, PubMed, and PsychINFO as well as reference lists of existing studies were searched to select eligible articles. Out of the 55 studies found, 14 met the inclusion criterion of an original empirical study on LSBs in people with dementia. RESULTS: The majority of the LSBs were tangible books, although some digital applications were also found. The LSBs were created mostly in individual sessions in nursing homes with a median of six sessions. Some studies only focused on the person with dementia, while others also examined (in)formal caregivers. Most studies used qualitative interviews, case studies, and/or (pilot) randomized controlled trial (RCTs) with small sample sizes. Qualitative findings showed the value of LSBs in triggering memories and in improving the relation with the person with dementia. Quantitative effects were found on, e.g. autobiographical memory and depression of persons with dementia, quality of relationship with informal caregivers, burden of informal caregivers, and on attitudes and knowledge of formal caregivers. CONCLUSIONS: This systematic review confirms that the use of LSBs to support reminiscence and person-centered care is promising, but larger RCTs or implementation studies are needed to establish the effects of LSBs on people with dementia.

Structural Validity of the World Assumption Scale.

The World Assumption Scale (WAS) is a frequently used measure in trauma research. The 32 items of the WAS are intended to represent eight assumptions about the benevolence of the world, the meaningfulness of events, and the worthiness of the self. Debate about the validity of the WAS is ongoing, particularly in terms of its empirical factor structure; some studies have confirmed a model of eight correlated factors whereas several other studies have not. The WAS items were administered to a clinical sample of patients who sought professional help because of posttraumatic complaints (n = 1,791) as well as a sample of healthcare professionals (n = 236). We split the clinical sample into three subsamples, then performed exploratory factor analysis using data from one subsample and tested the factor structure with confirmatory factor analysis using the other two subsamples. A consistent model of eight correlated factors was demonstrated, with almost all factors showing acceptable reliability, Cronbach's αs = .68-.84. We tested this factor model against data from the sample of healthcare professionals with increasingly stringent levels of invariance and found it to be scalar invariant (same structure, loadings, and thresholds). In a regression analysis, five factors showed significant associations with posttraumatic stress disorder (PTSD) symptoms, and two factors had unique associations with PTSD symptoms after we controlled for traumatic events: Self-Worth, ß = -.31; and Luck, ß = -.15. Future research should aim to distinguish between different assumptions and their individual influences on posttraumatic complaints.

Precious memories: a randomized controlled trial on the effects of an autobiographical memory intervention delivered by trained volunteers in residential care homes.

OBJECTIVES: This study assesses the effects of an autobiographical memory intervention on the prevention and reduction of depressive symptoms in older persons in residential care. Trained volunteers delivered the intervention. METHODS: A randomized controlled trial was carried out with depressive symptoms as the primary outcome. The experimental condition received the intervention Precious Memories one-on-one, whereas the control condition had individual unstructured contacts with a volunteer. Participants were 86 older persons living in residential care. There were three measurements: pre-intervention, post-intervention (2 months after the first measurement), and follow-up (8 months after the first measurement). Besides depressive symptoms, the retrieval of specific positive memories was measured as a process variable. Anxiety, loneliness, well-being, and mastery were assessed as secondary outcomes. RESULTS: Depressive symptoms improved equally in the intervention and the control condition at post-measurement. Participants with clinically relevant depressive symptoms also maintained the effects at follow-up in both conditions. The retrieval of specific positive memories improved more in the autobiographical memory intervention, although this was not maintained at follow-up. Anxiety and loneliness improved equally well in both conditions, but no effects were found for well-being or mastery. CONCLUSION: It is concluded that volunteers can deliver the intervention and contribute to the mental health of this highly vulnerable group of older adults.

Validation of the Mental Health Continuum-Short Form and the dual continua model of well-being and psychopathology in an adult mental health setting.

OBJECTIVE: The growing evidence for the dual continua model of psychopathology and well-being has important implications for measuring outcomes in mental health care. The aim of the current study is to validate a measure of well-being as well as the dual continua model in adults with mood, anxiety, personality, and developmental disorders. METHODS: 472 adult psychiatric outpatients filled out the Mental Health Continuum-Short Form (MHC-SF) and the Outcome Questionnaire before start of treatment. RESULTS: Confirmatory factor analyses (CFA) confirmed the three-factor structure of emotional, psychological, and social well-being of the MHC-SF. The dual continua model had the best fit in the complete sample and the different diagnostic groups. CONCLUSION: The MHC-SF is a reliable and valid instrument to measure well-being in the psychiatric population. Although relatively high correlations between psychopathology and well-being exist, the results underline the importance to measure well-being in addition to psychopathology in mental health care.

The effectiveness of creating an online life story book on persons with early dementia and their informal caregivers: a protocol of a randomized controlled trial.

BACKGROUND: Dementia has a high burden for patients, informal caregivers and society. Given changes in care systems, more persons with dementia will live longer at home. However, living at home (with dementia) with a good quality of life is not easy to achieve. Dementia is often accompanied by neuropsychiatric symptoms like apathy, agitation, depression, and anxiety, which have a negative impact on quality of life. Whereas cognitive deterioration can hardly be influenced, it is possible to reduce neuropsychiatric symptoms. As autobiographical memories remain intact for a relatively long time in dementia, reminiscence interventions can promote feelings of pleasure and trust. The Online Life Story Book (OLSB) allows to digitally share memories (stories, pictures, video or audio fragments). The main objective is to study the effects of the OLSB on neuropsychiatric symptoms. The study has four secondary objectives: 1) to study the effectiveness of the intervention on the burden and quality of life of the primary informal caregiver; 2) to provide a preliminary health-economic evaluation; 3) to study the (time to) nursing home admittance as a longer term effect; 4) to provide a process evaluation. METHODS AND DESIGN: A randomized controlled trial with individual randomization to one of two conditions is conducted: 1) intervention "Online Life Story Book"; 2) control condition (care as usual). Participants are persons with early dementia and their primary caregivers. In the intervention OLSB, a trained volunteer guides the participants through the process of putting together a timeline of their lives during 5 meetings within a period of 8-10 weeks. To assess the effects of the intervention on the primary outcome, neuropsychiatric symptoms, the Neuropsychiatric Inventory (NPI) will be assessed at three time points: before the intervention (baseline, T0), 3 months (T1) and 6 months (T2) post baseline. DISCUSSION: When proven effective, the Online Life Story Book can be a valuable addition to the existing provision of care for persons with dementia and their informal caregivers. TRIAL REGISTRATION: This study has been approved by the Twente Medical Ethics Committee under the file number p16-04 (Dutch Trial Register: NTR5939 , date of registration: 14 March 2016).

[The Well-Being Measure - dementia: A validation study]. / Validatieonderzoek Welzijnsmeter-dementie.

The Well-Being Measure - dementia is a digital observation instrument that assesses the well-being of persons with dementia on four domains of quality of life: Mental well-being, Physical well-being, Participation, and Living arrangements. Its goal is to assess the well-being of persons with dementia in an easy and positive way. Besides illness-related symptoms and problems, the instrument also assesses positive aspects of functioning. It visualizes the results and provides specific behavioural advice to the caregivers. The goal of the present article is to conduct a first psychometric analysis: factor structure, reliability (Cronbach's alpha), concurrent, and convergent validity.Observations were carried out among 168 persons with dementia in eleven different small-scale psychogeriatric wards. Five existing instruments were used among 63 persons to validate the Well-Being Measure-dementia: quality of life, neuropsychiatric symptoms, care dependency, depression, and agitation.The expected factor structure was found in each of the four domains. Coefficients were high on the expected factor and low on the other factor(s). The scale means were on the positive side, but showed an adequate range and variability. Reliability was satisfactory to good. The relation with existing scales was moderate to strong. The pattern of relations was consistent with the measurement intentions of the different existing instruments.The Well-Being Measure - dementia appears to be a valid and reliable scale. Further studies should assess its test-retest reliability, sensitivity to change and relation with the course of dementia. Current experience shows that the instrument is also useful in everyday practice.

Need fulfillment, need importance, and depressive symptoms of residents over the first eight months of living in a nursing home.

BACKGROUND: Based on self-determination theory and adaptation theories, the study aim was to investigate the relationship between need fulfillment (of autonomy, relatedness, and competence), need importance, and depressive symptoms during the first months of living in a nursing home. METHODS: Eight-month longitudinal questionnaire study in which 75 persons newly admitted to units for physically frail residents participated at baseline. Twenty-three longitudinal participants were remaining at the third and final measurement wave. RESULTS: The results show a main effect of need fulfillment and an interaction effect of need fulfillment and need importance on depressive symptoms over time. A prototypical plot shows that residents with low need fulfillment had higher initial levels of depressive symptoms that decreased modestly over time, regardless of their need importance. Residents with high need fulfillment had lower initial levels of depressive symptoms, but their trajectories differed for participants with low and high need importance. Residents with low need importance started with lower levels of depressive symptoms but remained stable over time, whereas residents with high need importance had more depressive symptoms at T1 that decreased slightly over time. CONCLUSIONS: In general, depressive symptoms do not change over time. However, individual trajectories of depressive symptoms seem to depend on individual need fulfillment and need importance. The residents that consider need fulfillment to be highly important but experience low need fulfillment had higher initial levels of depressive symptoms that decreased modestly over time, although the level of depressive symptoms remained higher as compared to the other residents.

Time to flourish: the relationship of temporal perspective to well-being and wisdom across adulthood.

OBJECTIVES: Despite the centrality of time to the aging process, the well-being consequences of different temporal orientations for optimal aging are poorly understood. We investigate one underexamined area of temporal orientation, namely a balanced time perspective, in a large, lifespan sample from the Netherlands. METHOD: Participants consisted of 512 Dutch adults ranging in age from 17 to 92 years (Mage = 46.46, SD = 21.37), including 186 male and 326 females. Participants completed a measure of balanced time perspective, mental health, and wisdom. RESULTS: RESULTS indicated that a balanced time perspective uniquely predicted both mental health and wisdom even after controlling for demographic, physical health, and personality variables. Younger adults tended to be more future-oriented relative to older adults while older adults tended to be more past-oriented relative to younger adults. Further, both midlife and younger adults were more likely to have a balanced time perspective relative to older adults. CONCLUSION: A balanced time perspective is associated with higher well-being and wisdom across the adult age span.

The development and initial validation of the narrative foreclosure scale.

OBJECTIVES: As people grow older, identity development in later life becomes a more and more relevant topic. Studying processes that hinder or promote identity development in later life is of importance. Within this broader field, there has been a growing interest in narrative foreclosure. Our goal was to develop a short, reliable and easy-to-use instrument measuring narrative foreclosure and to validate this instrument in two samples. METHODS: The narrative foreclosure scale (NFS) was validated in two studies with a sample of middle-aged adults (n = 319) and a sample with older adults (n = 174). Several analyses were conducted to assess the psychometric properties, the factor-structure and incremental validity of the scale. RESULTS: Confirmatory factor analyses generally showed an acceptable fit of the two-factor (NF-Future and NF-Past) model to the data in both samples. Both factors of the NFS demonstrated adequate to good internal consistency, with alpha coefficients ranging from .79 for NF-Past in study 2 to .88 for NF-Future in study 1. Construct validity was good as shown by moderate to large correlations to related constructs. The scale adds a unique portion of explained variance to positive mental health, thereby showing the incremental validity of the NFS. CONCLUSION: A reliable scale is now available that allows to study the premature hindering of identity development in older populations. The use of the NFS as a process measure in studies on the effectiveness of interventions aiming at meaning making and identity development, such as life-review therapy and narrative therapy, is also recommended.

Nudging socially isolated people towards well-being with the 'Happiness Route': design of a randomized controlled trial for the evaluation of a happiness-based intervention.

BACKGROUND: The Happiness Route is an innovative intervention that uses a happiness-based approach for people with an accumulation of risk factors for low well-being: socially isolated people with health impairments and a low socioeconomic status. The goal of this intervention is to improve well-being by engaging participants in intrinsically motivated activities with methods from positive psychology. We hypothesize that the primary outcome measure, emotional, social and psychological well-being of participants of the Happiness Route, will increase in comparison to the traditional and commonly-used problem-based approach. Secondary outcome measures are health-related quality of life, psychosocial functioning and health care consumption. METHODS AND DESIGN: Participants will be socially isolated people with health problems and a low socioeconomic status. Participants will be recruited in ten Dutch communities and candidates will be signed up by intermediaries, professionals from the health and social sector. Randomly assigned, half of the participants will follow the Happiness Route and half of the participants will follow the active, problem-focused control group 'Customized Care'. In total, 256 participants will be included. In both conditions, participants will receive counseling sessions from trained counselors. In the control group, participants will talk about their problems and the care they get and counselors help to optimize their care. In the Happiness Route, the counselor ask questions such as "How do you want to live your life?". The intervention helps people to find their 'passion', i.e., a positive goal-engaged and intrinsically motivated activity. It enables them to follow their passion through by a once-only personal happiness budget (maximal €500). We use well-validated and reliable questionnaires to measure primary and secondary outcome measures at baseline, directly after the intervention and at a nine-month follow-up. DISCUSSION: Shortcomings of earlier intervention studies in positive psychology will be tackled with this study, such as having a target group who is especially vulnerable for low well-being. The practice-based setting is especially interesting, as it can give valuable insights in how positive psychology interventions work in practice, but can also give rise to several challenges. TRIAL REGISTRATION: Dutch Trial Register, trial registration number TC=3377NTR.http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=3377.

Positive psychology interventions: a meta-analysis of randomized controlled studies.

BACKGROUND: The use of positive psychological interventions may be considered as a complementary strategy in mental health promotion and treatment. The present article constitutes a meta-analytical study of the effectiveness of positive psychology interventions for the general public and for individuals with specific psychosocial problems. METHODS: We conducted a systematic literature search using PubMed, PsychInfo, the Cochrane register, and manual searches. Forty articles, describing 39 studies, totaling 6,139 participants, met the criteria for inclusion. The outcome measures used were subjective well-being, psychological well-being and depression. Positive psychology interventions included self-help interventions, group training and individual therapy. RESULTS: The standardized mean difference was 0.34 for subjective well-being, 0.20 for psychological well-being and 0.23 for depression indicating small effects for positive psychology interventions. At follow-up from three to six months, effect sizes are small, but still significant for subjective well-being and psychological well-being, indicating that effects are fairly sustainable. Heterogeneity was rather high, due to the wide diversity of the studies included. Several variables moderated the impact on depression: Interventions were more effective if they were of longer duration, if recruitment was conducted via referral or hospital, if interventions were delivered to people with certain psychosocial problems and on an individual basis, and if the study design was of low quality. Moreover, indications for publication bias were found, and the quality of the studies varied considerably. CONCLUSIONS: The results of this meta-analysis show that positive psychology interventions can be effective in the enhancement of subjective well-being and psychological well-being, as well as in helping to reduce depressive symptoms. Additional high-quality peer-reviewed studies in diverse (clinical) populations are needed to strengthen the evidence-base for positive psychology interventions.