Psychometric evaluation of the Temporal Experience of Pleasure Scale (TEPS) in a German sample

Article

Reference

Psychometric evaluation of the Temporal Experience of Pleasure Scale (TEPS) in a German sample

SIMON, Joe J, et al.

Abstract

Anhedonia, or the inability to experience pleasure, is commonly observed in schizophrenia. It has been suggested that patients with schizophrenia are unable to predict future pleasurable events, but show intact experience of in-the-moment pleasure. Therefore, the Temporal Experience of Pleasure Scale (TEPS), a self-report measure allowing the assessment of anticipatory and consummatory pleasure, has been developed. To validate the German version of the TEPS, we recruited 59 healthy control participants and 51 patients with schizophrenia or schizoaffective disorder who completed the TEPS as well as a battery of psychometric tests to assess psychopathology, in particular self-rated anhedonia and clinician-rated apathy as well as overall measures of negative symptoms. We found acceptable to good internal consistency and a factor structure comparable to the original version. Scores of the TEPS were related to measures of anhedonia and apathy, but not with other measures of psychopathology. The present results suggest that the German version of the TEPS shows adequate reliability and validity to assess the construct of [...]

SIMON, Joe J, et al . Psychometric evaluation of the Temporal Experience of Pleasure Scale (TEPS) in a German sample. Psychiatry Research , 2018, vol. 260, p. 138-143

DOI : 10.1016/j.psychres.2017.11.060 PMID : 29195165

Available at:

http://archive-ouverte.unige.ch/unige:111182

Disclaimer: layout of this document may differ from the published version.

1 / 1

Contents lists available atScienceDirect

Psychiatry Research

journal homepage:www.elsevier.com/locate/psychres

Psychometric evaluation of the Temporal Experience of Pleasure Scale (TEPS) in a German sample

Joe J. Simon

, Johannes Zimmermann

, Sheila A. Cordeiro

, Ina Marée

, David E. Gard

, Hans-Christoph Friederich

, Matthias Weisbrod

, Stefan Kaiser

aDepartment of General Psychiatry, Center of Psychosocial Medicine, University of Heidelberg, Germany

bDepartment of General Internal Medicine and Psychosomatics, Centre for Psychosocial Medicine, Heidelberg, Germany

cDepartment of Psychosomatic Medicine and Psychotherapy, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany

dPsychologische Hochschule Berlin, Berlin, Germany

eDepartment of Psychology, San Francisco State University, USA

fDepartment of Psychiatry and Psychotherapy, SRH Klinikum Karlsbad-Langensteinbach, Germany

gDivision of Adult Psychiatry, Department of Mental Health and Psychiatry, Geneva University Hospitals, Geneva, Switzerland

A R T I C L E I N F O

Keywords:

Schizophrenia Anhedonia Apathy

Negative symptoms

A B S T R A C T

Anhedonia, or the inability to experience pleasure, is commonly observed in schizophrenia. It has been suggested that patients with schizophrenia are unable to predict future pleasurable events, but show intact experience of in-the-moment pleasure. Therefore, the Temporal Experience of Pleasure Scale (TEPS), a self-report measure allowing the assessment of anticipatory and consummatory pleasure, has been developed. To validate the German version of the TEPS, we recruited 59 healthy control participants and 51 patients with schizophrenia or schizoaffective disorder who completed the TEPS as well as a battery of psychometric tests to assess psycho- pathology, in particular self-rated anhedonia and clinician-rated apathy as well as overall measures of negative symptoms. We found acceptable to good internal consistency and a factor structure comparable to the original version. Scores of the TEPS were related to measures of anhedonia and apathy, but not with other measures of psychopathology. The present results suggest that the German version of the TEPS shows adequate reliability and validity to assess the construct of anhedonia. However, differential aspects of anticipatory and consummatory pleasure should be further investigated in clinical samples.

1. Introduction

Anhedonia–an impairment in the ability to experience pleasure–is a core negative symptom of schizophrenia and can also be observed in other psychiatric disorders such as depression and substance abuse (Meehl, 1962; Treadway and Zald, 2013). However, research on an- hedonia in patients with schizophrenia has revealed seemingly incon- sistentfindings (Horan et al., 2006). Patients with schizophrenia report anhedonia in questionnaires and interviews, but seem to experience as much pleasant emotions as healthy subjects in response to evocative, real life stimuli.

More recently, a more differentiated approach to anhedonia has been proposed to integrate thesefindings (Gard et al., 2006, 2007). This approach is based on the division of anhedonia into two aspects–an- ticipatory and consummatory anhedonia (Klein, 1984). This is in line with neurobiologicalfindings, which suggest at least two partially se- parate systems to subserve anticipatory and consummatory pleasure

(Berridge and Robinson, 2003; Knutson et al., 2001). Anticipatory pleasure includes the prediction of future pleasure and the current ex- perience of pleasure in expectation of a future activity, while con- summatory pleasure describes the in-the-moment experience of plea- sure when engaging in a pleasurable activity. It has been suggested that a differential deficit in the components of pleasure could have im- portant implications for therapy development (Edwards et al., 2015;

Favrod et al., 2015).

In order to psychometrically assess these two domains of anhedonia, Gard et al. (2006)have developed the Temporal Experience of Pleasure Scale (TEPS). The TEPS is a short 18-item questionnaire, which requires the rating of statements relating to pleasure on a 6-point Likert scale.

The scale has a two-factor structure separated into anticipatory and consummatory pleasure (TEPS-ANT and TEPS-CON). Patients with schizophrenia have been found to show reduced anticipatory but intact consummatory pleasure in comparison with healthy controls (Favrod et al., 2009; Gard et al., 2007), although this has not been observed in

https://doi.org/10.1016/j.psychres.2017.11.060

Received 31 January 2017; Received in revised form 12 October 2017; Accepted 18 November 2017

⁎Correspondence to: Centre for Psychosocial Medicine, General Internal Medicine and Psychosomatics, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany.

E-mail address:[email protected](J.J. Simon).

Available online 21 November 2017

0165-1781/ © 2017 Elsevier B.V. All rights reserved.

T

all studies (Strauss et al., 2011).

Moreover, a specific pattern of associations has been suggested with TEPS-ANT being more strongly related to social, as opposed to physical anhedonia–as measured by the classic Physical and Social Anhedonia scale developed by Chapman (Favrod et al., 2009; Gard et al., 2007). In addition, TEPS-ANT has been observed to be closely associated with anhedonia as measured by an interview-based negative symptom scale.

Again, thesefindings have been replicated in some but not all studies (Strauss et al., 2011).

Another construct of interest is apathy, which has been defined as an impairment in goal-directed behavior due to a loss of motivation (Kaiser et al., 2016; Marin, 1991). Current theories of apathy in schi- zophrenia consider anticipatory pleasure as an important driving force for motivated goal-directed behavior (Kring and Barch, 2014). Thus, one would expect that TEPS-ANT should be specifically associated with apathy. To our knowledge, convergent validity of the TEPS has not been investigated with a specific assessment instrument for apathy. There- fore, we included the clinician version of the Apathy Evaluation Scale as used in previous studies with patients with schizophrenia orfirst-epi- sode psychosis (Faerden et al., 2008; Fervaha et al., 2015).

We developed the following hypotheses: (1) The TEPS shows a 2- factor structure similar to the original English version. (2) Patients with schizophrenia show a specific reduction in anticipatory pleasure. (3) Convergent validity would be demonstrated by significant associations of both TEPS subscales with existing scales of anhedonia. Furthermore, we expected the TEPS-ANT subscale to be associated with clinician- rated apathy.

2. Methods 2.1. Participants

59 healthy control participants and 51 patients with schizophrenia (N = 36) or schizoaffective disorder (N = 15) recruited from the University Hospital Heidelberg and SRH Clinic Karlsbad- Langensteinbach took part in the study. Healthy participants were re- cruited via flyers and advertisements in local papers and had to be without any current DSM-IV psychiatric disorder and history of psy- chotic disorder or psychopharmacological treatment. All participants had to be right-handed and without drug abuse or neurological dis- order. A structured clinical interview for DSM-IV (M.I.N.I., Sheehan et al., 1998) was employed in patients and in healthy participants to either confirm diagnoses or to rule out both DSM Axis I disorders and current drug abuse. All patients were medicated with atypical anti- psychotics, nine patients were additionally treated with mood stabi- lizers, and twelve patients were additionally treated with anti- depressants. Medication was stable for at least four weeks. We calculated chlorpromazine equivalents based on the formulas provided by Andreasen et al. (2010). Groups differed significantly in age and gender ratio but there were no differences in education years of the participants as well as premorbid intelligence as assessed by a voca- bulary based test (MWT-B,Lehrl et al., 1995). Demographic data for the groups are presented inTable 1. The present study complies with the declaration of Helsinki, version 2008, and was approved by the Ethics

Committee of the Medical School of the University of Heidelberg. All participants provided written informed consent.

2.2. German version of the TEPS

The original version of the TEPS (Gard et al., 2006) consists of 10 questions assessing anticipatory pleasure (TEPS-ANT) and 8 questions assessing consummatory pleasure (TEPS-CON) using a 6-point fixed choice response format ranging from 1 = very false for me to 6 = very true for me. Items designed to assess anticipatory pleasure enquire about pleasure experienced in anticipation of an enjoyable stimulus, e.g.“When I think about eating my favorite food, I can almost taste how good it is”. Consummatory pleasure is measured using items which refer to pleasure experienced during the exposure to an enjoyable stimulus, e.g.:“The smell of freshly cut grass is enjoyable to me”. A higher score in both subscales indicates higher anticipatory or consummatory pleasure respectively. In afirst step, the scale was translated from English to German by a native German speakerfluent in English. In a second step, a “back-translation” from German to English by a native English speakerfluent in German without knowledge of the original English version was employed to ensure the semantic equivalence of the German translation. Thefinal German version included the 18 original items from the TEPS.

2.3. Psychometric assessments

In addition to the TEPS, we employed a number of psychometric measurements to assess anhedonia, apathy, depression and psychotic- like experiences in healthy subjects as well as level of symptom ex- pression in patients. Using self-report scales, we assessed anhedonia in both groups using the Chapman scales for physical and social anhe- donia (PAS/SAS, Burgdörfer and Hautzinger, 1987), as well as de- pression in healthy participants using the Beck Depression Inventory (BDI,Hautzinger et al., 2006). The remaining measurements all em- ployed clinician ratings. Apathy was assessed in both groups using the Apathy Evaluation Scale (AES, Lueken et al., 2006). Depression was assessed in patients with schizophrenia using the Calgary depression scale (Müller et al., 1999). Furthermore, negative symptoms were measured in both groups using the Scale for the Assessment of Negative Symptoms (SANS, Andreasen, 1989). We calculated the SANS total score by summing all global rating items excluding the attention sub- scale. Positive symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS,Kay et al., 1987). Ratings of symptoms were performed by trained clinicians (JJS, IM and SAC). In order to give an estimate of inter-rater reliability, 11 patients with schizophrenia who did not participate in the study were independently rated using the PANSS by JJS and SAC. The obtained intraclass correlation coefficient (two-way mixed model, analysis of absolute agreement) was 0.938 (95%CI:0.796, 0.983) for the positive scale, 0.964 (95%CI:0.872, 0.990) for the negative scale and 0.919 (95%CI:0.731, 0.977) for the general psychopathology scale, indicating an excellent inter-rater re- liability.

2.4. Data analysis

Group differences were analyzed using Multivariate Analysis of Variance (MANOVA) and two-samplet-tests. Scales showing unequal variances between groups (as assessed by a Levene's test) were com- pared using Welch t-tests (unequal variances were observed in the following scales: TEPS-CON, SAS, AES, PANSS and SANS). Internal consistency of the scales was estimated by calculating Cronbach's alpha.

Item analysis was performed by calculating the mean corrected item- total correlations. To validate the two-factor structure of the original TEPS as proposed byGard et al. (2006), we performed a confirmatory factor analysis (CFA) in the joint sample on the basis of the polychoric correlation matrix with robust weighted least squares estimation using Table 1

Participant demographics.

CN (n= 59) SZ (n= 51)

Mean age 27.9 (9.2) 32.8 (10.3)^*

Females/males 41/18 23/28^**

Mean education years 15.8 (SD = 2.9) 15 (SD = 3.4)

MWT-B 29.2 (SD = 3.5) 28 (SD = 4)

* p < 0.05.

** p < 0.01.

J.J. Simon et al. Psychiatry Research 260 (2018) 138–143

139

lavaan (Rosseel, 2012) implemented inR Core Team (2014). Modelfit was evaluated through theχ²test statistic, root mean square error of approximation (RMSEA) as well as the comparative fit index (CFI).

Regarding the criteria for assessing the quality of our model we follow the recommendations by Hopwood and Donnellan (2010)for multi- dimensional constructs: RMSEA goodfit < 0.06, acceptablefit < 0.1;

and CFI goodfit > 0.95, acceptablefit > 0.9.

To assess convergent and discriminant validity of the TEPS, we performed correlational analyses between the TEPS subscales and measures of anhedonia, apathy and depression using Spearman's rho.

For comparison between correlation coefficients Steiger's test was em- ployed (Lee and Preacher, 2013).

3. Results

3.1. Group differences

Mean scores and standard deviations of the clinical measures are given inTable 2. Calculating a MANOVA with TEPS scores as depen- dent variables indicated no significant group effect (F(2,107) = 1.82, p

= 0.167). However, due to the expected differences in anticipatory- and consummatory pleasure in the patient group, we performed planned comparisons which revealed a trend-wise effect of group for the TEPS-ANT scale (F(1,108) = 3.67, p = 0.058) indicating lower scores in the patient group. There was no significant difference for the TEPS-CON scale (F(1,108) = 1.18, p = 0.28). Since we observed un- equal variance in the TEPS-CON scale, we additionally performed a Welcht-test to assess differences between groups, here we also failed to observe a significant difference (t(1,89) = 1.08, p = 0.29).

3.2. Influence of demographic variables on group differences

To assess the influence of age, gender, education years and in- telligence (assessed with the MWT-B), we performed additional MANOVA analyses with the inclusion of these measures as covariates.

Only education years showed to have a significant effect (F(2,106) = 6.13, p = 0.003). The group difference for the TEPS-ANT scale became significant when controlling for education CI(95%): 0.496–5.485, p = 0.019, indicating lower scores in the patient group. Group differences for the TEPS-CON scale remained non-significant (CI(95%): −1.086 –3.965, p = 0.261). A closer inspection revealed that education years were negatively related to anticipatory pleasure in the patient group (r

=−0.377, p = 0.006). In other words patients with higher education

level showed less anticipatory pleasure. This effect was not observed in healthy controls (r =−0.198, p = 0.132). There was no significant correlation of TEPS scores with other demographic variables.

3.3. Confirmatory factor analysis

The initial test of the theoretical two-factor structure indicated a still acceptable, but clearly less than perfect modelfit. We observed a χ²(134) of 238.7 (p < 0.001), a RMSEA of 0.085 (90%CI:0.067, 0.102) and a CFI of 0.905. The estimated correlation of the two latent factors was 0.752. Standardized factor loadings for all items are given in Table 4. Since one item in the TEPS-ANT scale showed a very low factor loading (“I don't look forward to things like eating out at restaurants”, factor loading of−0.010), we repeated the CFA after excluding this item. Regarding thefit indices for this modified two-factor model we observed χ²(118) of 213.6 (p < 0.001), a RMSEA of 0.086 (90%CI:0.067, 0.104) and a CFI of 0.914. Thus, exclusion of this item only leads to minimal improvement in one of thefit indices.

3.4. Internal consistency analysis

Table 3shows the results of the internal consistency analysis using Cronbach's alpha. Similar to a previous report (Strauss et al., 2011), we observed acceptable to good internal consistency for TEPS total score and subscales in the patient group, whereas results in the healthy control group are somewhat lower. In healthy controls, the mean cor- rected item-total correlation was r = 0.346 for the TEPS-ANT scale and r = 0.345 for the TEPS-CON scale. In patients, the mean corrected item- total correlation was r = 0.375 for the TEPS-ANT scale and r = 0.559 for the TEPS-CON scale. Furthermore, we observed a positive correla- tion between the TEPS-ANT and the TEPS-CON scale in the healthy control group (r = 0.414, p = 0.001) and in patients with schizo- phrenia (r = 0.658, p < 0.001).

3.5. Convergent and discriminant validity

Correlations between the TEPS scales and additional psychometric measures are given inTable 5. We observed a negative correlation in both groups between the TEPS-ANT scale and anhedonia scores (PAS/

SAS, rs≤0.293, ps < 0.05), as well as between the TEPS-CON scale and anhedonia scores (rs≤0.337, ps < 0.01). Only the patient group displayed a negative correlation between apathy scores (AES) and both the TEPS-ANT and TEPS-CON (r = −0.499, p < 0.001 and r =

−0.335, p < 0.05, respectively). Steiger's test revealed no significant differences between these two correlations (z = −1.37, p = 0.17), although the strength of correlation was numerically higher between the AES and the TEPS-ANT.

While there was no relation between the TEPS and depression scores in the patient group (Calgary scale, ps > 0.05), healthy controls showed a negative correlation between depression scores (BDI) and TEPS-CON (r =−0.259, p < 0.05). We observed no relation between TEPS scores Table 2

Difference in performance on self-report measures between healthy controls and in- dividuals with schizophrenia.

Measure CN (n= 59) SZ (n= 51)

TEPS-ANT 44.51 (6.5) 42 (7.11)

TEPS-CON 37.92 (5.5) 36.55 (7.63)+

PAS 9.02 (5.57) 11.65 (6.99)*

SAS 9.44 (6.5) 11.33 (6.27)+

AES 9.89 (5.73) 15.14 (8.26)*** +

PANSS-POS 8.14 (1.63) 10.55 (3.33)*** +

PANSS-NEG 8.41 (2.39) 12.31 (6.75)*** +

PANSS-GEN 17.93 (3.01) 24.45 (5.4)*** +

SANS-tot 1.08 (2.16) 3.67 (3.49)*** +

SANS-apathy global 0.49 (1.29) 1.76 (1.72)*** + SANS-anhedonia global 0.32 (0.79) 0.98 (1.04)*** +

BDI 5.34 (5.92) /

Calgary 4.25 (5.13)/

Values given as mean ± SD. * p < 0.05, ** p < 0.01, *** p < 0.001, + Welcht-test.

TEPS-ANT: Temporal experience of pleasure scale/anticipatory scale, TEPS-CON:

Temporal experience of pleasure scale/consummatory scale, PAS/SAS: Physical and so- cial anhedonia scales, AES: Apathy evaluation scale, PANSS: Positive and negative symptom scale, SANS: Scale for the assessment of negative symptoms, BDI: Beck de- pression inventory.

Table 3

Internal consistency of self-report measures in individuals with schizophrenia and con- trols.

Measure CN (n = 59) SZ (n = 51)

TEPS

Total scale 0.749 0.853

TEPS-ANT 0.672 0.694

TEPS-CON 0.641 0.827

Chapman scales

Total scale 0.89 0.902

PAS 0.795 0.852

SAS 0.881 0.848

AES 0.767 0.937

and assessments of negative as well as positive symptoms (SANS and PANSS) in the patient group (ps > 0.05). The healthy control group showed a negative relation between negative symptoms (SANS) and the TEPS-ANT (r =−0.259, p < 0.05).

Finally, we correlated chlorpromazine equivalents with the TEPS- scale. Although we did not observe a relation with the anticipatory subscale (p = 0.385), we found a significant positive correlation be- tween medication and the consummatory subscale (r = 0.306, p = 0.029), indicating that a higher dose of antipsychotic medication is related to increased consummatory pleasure. A closer inspection of the correlational plot revealed that an outlier may have influenced the re- sults (Z = 4.1), the correlation failed to reach significance when

excluding this subject (r = 0.228, p = 0.111).

4. Discussion

The present study presents the validation of the German Version of the TEPS. Scale characteristics and factor structure are comparable to the original English version. Furthermore, the association of the TEPS with the Chapman Anhedonia Scales and Apathy Evaluation Scale de- monstrates external validity. However, we found only limited evidence that patients with schizophrenia show a specific deficit in anticipatory pleasure and that the TEPS subscales show specific associations with other measures of psychopathology.

The confirmatory factor analysis of the two-factor model with TEPS- ANT and TEPS-CON subscales showed a less than optimal, but still acceptable modelfit. These fit indexes are slightly lower than those reported in other studies testing the two-factor structure of the TEPS (Chan et al., 2012; Favrod et al., 2009). Internal consistency was ac- ceptable and in the same range as previous studies (Gard et al., 2006), although somewhat lower in healthy controls than in patients. Fur- thermore the large difference in corrected item-total correlation be- tween healthy controls and patients for the TEPS-CON scale suggests that the factor structure may differ between samples. The item-total correlations and standardized factor loadings of the subscales were also acceptable with the exception of one item in the TEPS-ANT scale.

However, elimination of the item did not lead to a major improvement in modelfit. Therefore, it seems justified to use all of the items of the original TEPS for the two factors in the German version (Clark and Watson, 1995). Overall, in order to obtain a definitive confirmation of the German version's factor structure, replication in a larger sample would be helpful.

We observed a trend-wise significant difference between patients with schizophrenia and healthy controls for the TEPS-ANT but not for the TEPS-CON scale, which certainly has to be interpreted with caution given the modest sample size. This pattern of differences between pa- tients and controls is in line with some, but not all previous studies (Favrod et al., 2009; Gard et al., 2007; Li et al., 2015; Strauss et al., 2011). On a cautionary note it has to be acknowledged that these group differences seem to reflect gradual differences between the two TEPS subscales rather than two categorically different constructs.

The existing literature offers two possible explanations for the Table 4

Standardized factor loadings for the translated items of the TEPS scale obtained via confirmatory factor analysis.

CFA^a

Anticipatory factor Consummatory factor Anticipatory Factor

1 When I hear about a new movie starring my favorite actor, I can't wait to see it. 0.328

2 I look forward to a lot of things in my life. 0.787

3 Looking forward to a pleasurable experience is in itself pleasurable. 0.765

4 When I think of something tasty, like a chocolate chip cookie, I have to have one. 0.520

5 I get so excited the night before a major holiday I can hardly sleep. 0.448

6 When I'm on my way to an amusement park, I can hardly wait to ride the roller coasters. 0.316

7 I don't look forward to things like eating out at restaurants. −0.010

8 When I think about eating my favorite food, I can almost taste how good it is. 0.626

9 When ordering something offthe menu, I imagine how good it will taste. 0.653

10 When something exciting is coming up in my life, I really look forward to it. 0.605 Consummatory Factor

1 I enjoy taking a deep breath of fresh air when I walk outside. 0.682

2 The smell of freshly cut grass is enjoyable to me. 0.747

3 I love it when people play with my hair. 0.581

4 A hot cup of coffee or tea on a cold morning is very satisfying to me. 0.580

5 I appreciate the beauty of a fresh snowfall. 0.757

6 I really enjoy the feeling of a good yawn. 0.488

7 I love the sound of rain on the windows when I'm lying in my warm bed. 0.679

8 The sound of crackling wood in thefireplace is very relaxing. 0.618

aFactor loadings > 0.5 in bold font.

Table 5

Correlation between TEPS subscales and measures of anhedonia, apathy and depression (Spearman's rho).

Measure TEPS-ANT TEPS-CON

CN SZ CN SZ

PAS −0.382^** −0.499^*** −0.683^*** −0.656^***

SAS −0.414^*** −0.293^* −0.337^** −0.380^**

AES −0.172 −0.499^*** −0.112 −0.335^* BDI −0.117 −0.259^*

Calgary −0.152 0.023

SANS total score −0.259^* −0.101 −0.145 −0.036

SANS apathy score −0.114 −0.099 0.030 −0.049

SANS anhedonia score −0.114 −0.134 0.020 −0.134

PANSS positive subscale

−0.156 0.158 −0.010 0.216 PANSS negative

subscale

−0.228 0.042 −0.191 0.100 PANSS general subscale −0.102 −0.090 −0.002 0.073

MWT-B 0.193 −0.284^* 0.093 −0.113

Mean education years −0.121 −0.377^** −0.043 −0.018 TEPS-ANT: Temporal experience of pleasure scale/anticipatory scale, TEPS-CON:

Temporal experience of pleasure scale/consummatory scale, PAS/SAS: Physical and so- cial anhedonia scales, AES: Apathy evaluation scale, PANSS: Positive and negative symptom scale, SANS: Scale for the assessment of negative symptoms, BDI: Beck de- pression inventory, MWT-B: vocabulary based intelligence test.

* p < 0.05.

** p < 0.01.

*** p < 0.001.

J.J. Simon et al. Psychiatry Research 260 (2018) 138–143

141

limited group differences observed for the TEPS-ANT scale. Firstly, Strauss et al. (2011) have suggested that group differences might be more pronounced when patients are treated with typical antipsychotics.

In our study, all patients were treated with atypical antipsychotics, which might limit impairments in anticipatory anhedonia. Second, Chan et al. (2010) found that patients with pronounced negative symptoms displayed lower TEPS-ANT scores than those with less ne- gative symptoms. In our study patients showed a low to moderate level of negative symptoms that corresponds to the low negative symptom group of the Chan et al. study. This indicates that in our study, patients with a lower level of negative symptoms might also have less anhedonic symptoms. In summary, treatment with atypical antipsychotics and relatively low levels of negative symptoms might have attenuated group differences regarding anticipatory pleasure in the present sample.

Additionally, this pattern was influenced by a negative association of anticipatory pleasure and education. However, it has to be noted that education and the TEPS-ANT were differentially associated in patients and controls, which may undermine the validity of our covariance analyses (Montgomery, 2008). Therefore, the impact of education on group differences in TEPS-ANT should be viewed with caution.

Nevertheless, the negative correlation between anticipatory pleasure and education is somewhat surprising given the previously observed negative relation between education level and amotivation (Cernovsky et al., 1994), as well as functional impairment (Foussias et al., 2009).

While these previous studies focused on objective assessment of moti- vation and functioning, the TEPS measures subjective experience. Pa- tients with higher levels of education might feel more impaired by difficulties in anticipating pleasure and consequently rate higher on the TEPS-ANT scale. Our patients had a relatively high level of education compared to previous TEPS studies, which may account for the lack of previous reports regarding this association. We have to acknowledge that this explanation is speculative at the moment and further research on the relationship between education, anhedonia and amotivation is needed.

Regarding convergent validity, in patients and controls both TEPS- subscales showed significant correlations with the Chapman Anhedonia Scales, in particular with the Physical Anhedonia Scale. However, un- like other studies no specific differences in associations between the two TEPS subscales were found. Furthermore, there was no significant association with clinician-rated anhedonia as assessed with the SANS.

This is in contrast with some, but not all previous studies (Gard et al., 2007; Strauss et al., 2011). It has to be kept in mind that the SANS focusses on observable behavior and the anhedonia subscale includes asociality. Recently developed negative symptom scales such as the Brief Negative Symptom Scale (Kirkpatrick et al., 2011) or the Com- prehensive Assessment Interview for Negative Symptoms (Kring et al., 2013) emphasize subjective experience more strongly and might lead to more consistent results. Regardless of the scale employed, a combina- tion of self-rating and observer-rating might be required to capture the full psychopathology of motivation and pleasure symptoms (Engel and Lincoln, 2016).

In contrast to the lack of association with SANS scores in patients, both TEPS-subscales were associated with clinician-rated apathy mea- sured by the AES. Since anticipated pleasure is considered an important driving force for motivated behavior, we expected a stronger associa- tion of TEPS-ANT with apathy. However, the difference between cor- relations was not statistically significant, although numerically stronger for TEPS-ANT. Thus, similar to thefindings for the Chapman scales, no diverging patterns of association were found for the two TEPS sub- scales. To explain the lack of differential associations with apathy it is important to note that the AES includes items that measure emotional reactivity. The consummatory subscale of the TEPS asks about specific activities, f.ex.“I enjoy taking a deep breath of fresh air”and requires the participant to “imagine”the described activity. This“looking for- ward” to an enjoyable experience may overlap with the concept of apathy as assessed by the AES and thus explain the observed relation.

Finally, convergent validity is in part supported by the association of consummatory anhedonia with self-rated depression. Since an asso- ciation with depression was only found in healthy controls, the inter- view based Calgary scale might tap different constructs than the self- rated Beck inventory. Furthermore, divergent validity was supported by an absence of associations with any PANSS subscales in both groups.

Some limitations of this study have to be considered. First, the sample size for the factor analysis was relatively small, even when combining healthy controls and patients with schizophrenia. Moreover, it is conceivable that the TEPS might not have an identical factor structure in patients and controls. For example, a previous report by Chan et al. (2012) found a four-factor model in a large sample of healthy Chinese college students. Second, in order to explore the as- sociation with depressive symptoms, the use of the same scale for both groups would have been helpful. We used different scales, because we considered the BDI and the CDS to be suitable only for controls and patients, respectively. Nevertheless, the use of different scales in the two groups remains an important limitation of our study. Future re- search should include self-rating and observer-rating across all parti- cipants to conclusively assess convergent validity of the TEPS-scale.

In conclusion, the German version of the TEPS shows a factor structure consistent with the original version of the scale with accep- table internal consistency of the subscales. The scale shows good con- vergent validity for the assessment of anhedonia. The differentiation between anticipatory and consummatory pleasure was only partially found in this study. However, there is some indication of a stronger impairment of patients with schizophrenia in anticipatory pleasure.

Overall, we hope that this German version of the TEPS will now be used in larger international studies in order to resolve the partially con- flictingfindings of the existing studies. Most importantly, studies with larger samples should allow developing a clearer picture of differential deficits in anticipatory and consummatory pleasure.

Disclosure

Drs. Simon, Cordeiro and Friederich have reported neither potential conflicts of interest nor any types of commercial orfinancial involve- ments. Drs. Weisbrod and Kaiser received speaker honoraria from Roche and royalties for cognitive test and training software from Schuhfried (none related to this study).

Funding/support

Dr Simon was supported by a post-doc scholarship from the medical faculty of the University of Heidelberg.

References

Andreasen, N.C., 1989. The Scale for the Assessment of Negative Symptoms (SANS):

conceptual and theoretical foundations. Br. J. Psychiatry Suppl. (7), 49–58.

Andreasen, N.C., Pressler, M., Nopoulos, P., Miller, D., Ho, B.C., 2010. Antipsychotic dose equivalents and dose-years: a standardized method for comparing exposure to dif- ferent drugs. Biol. Psychiatry 67 (3), 255–262.

Berridge, K.C., Robinson, T.E., 2003. Parsing reward. Trends Neurosci. 26, 507–513.

Burgdörfer, G., Hautzinger, M., 1987. Physische und soziale anhedonie Die evaluation eines forschungsinstruments zur messung einer psychopathologischen basisstörung.

Eur. Arch. Psychiatry Neurol. Sci. 236, 223–229.

Cernovsky, Z.Z., Landmark, J., Helmes, E., 1994. Are schizophrenic symptoms different in patients with higher education? Psychol. Rep. 75 (3 Pt 2), 1552–1554.

Chan, R.C., Wang, Y., Huang, J., Shi, Y., Wang, Y., Hong, X., Ma, Z., Li, Z., Lai, M.K., Kring, A.M., 2010. Anticipatory and consummatory components of the experience of pleasure in schizophrenia: cross-cultural validation and extension. Psychiatry Res.

175, 181–183.

Chan, R.C., Shi, Y., Lai, M., Wang, Y., Wang, Y., Kring, A.M., 2012. The temporal ex- perience of pleasure scale (TEPS): exploration and confirmation of factor structure in a healthy Chinese sample. PLoS One 7 (4), e35352.

Clark, L.A., Watson, D., 1995. Constructing validity: basic issues in objective scale de- velopment. Psychol. Assess. 7, 309–319.

Edwards, C.J., Cella, M., Tarrier, N., Wykes, T., 2015. Investigating the empirical support for therapeutic targets proposed by the temporal experience of pleasure model in schizophrenia: a systematic review. Schizophr. Res. 168 (1–2), 120–144.

Engel, M., Lincoln, T.M., 2016. Concordance of self- and observer-rated motivation and pleasure in patients with negative symptoms and healthy controls. Psychiatry Res.

247, 1–5.

Faerden, A., Nesv/aag, R., Barrett, E.A., Agartz, I., Finset, A., Friis, S., Rossberg, J.I., Melle, I., 2008. Assessing apathy: the use of the Apathy Evaluation Scale infirst episode psychosis. Eur. Psychiatry 23, 33–39.

Favrod, J., Ernst, F., Giuliani, F., Bonsack, C., 2009. Validation of the of Pleasure Scale (TEPS) in a French-speaking environment. L'Encephale 35 (3), 241–248.

Favrod, J., Nguyen, A., Fankhauser, C., Ismailaj, A., Hasler, J.D., Ringuet, A., Rexhaj, S., Bonsack, C., 2015. Positive Emotions Program for Schizophrenia (PEPS): a pilot in- tervention to reduce anhedonia and apathy. BMC Psychiatry 15, 231.

Fervaha, G., Foussias, G., Takeuchi, H., Agid, O., Remington, G., 2015. Measuring mo- tivation in people with schizophrenia. Schizophr. Res. 169 (1–3), 423–426.

Foussias, G., Mann, S., Zakzanis, K.K., van Reekum, R., Remington, G., 2009. Motivational deficits as the central link to functioning in schizophrenia: a pilot study. Schizophr.

Res. 115 (2–3), 333–337.

Gard, D.E., Gard, M.G., Kring, A.M., John, O.P., 2006. Anticipatory and consummatory components of the experience of pleasure: a scale development study. J. Res.

Personal. 40, 1086–1102.

Gard, D.E., Kring, A.M., Gard, M.G., Horan, W.P., Green, M.F., 2007. Anhedonia in schizophrenia: distinctions between anticipatory and consummatory pleasure.

Schizophr. Res. 93 (1–3), 253–260.

Hautzinger, M., Keller, F., Kühner, C., 2006. BDI-II. Beck-Depressions-Inventar Revision– Manual. Harcourt Test Services, Frankfurt.

Hopwood, C.J., Donnellan, M.B., 2010. How should the internal structure of personality inventories be evaluated? Personal. Social. Psychol. Rev. 14 (3), 332–346.

Horan, W.P., Kring, A.M., Blanchard, J.J., 2006. Anhedonia in schizophrenia: a review of assessment strategies. Schizophr. Bull. 32 (2), 259–273.

Kaiser, S., Lyne, J., Agartz, I., Clarke, M., Morch-Johnsen, L., Faerden, A., 2016.

Individual negative symptoms and domains–relevance for assessment, patho- mechanisms and treatment. Schizophr. Res.

Kay, S.R., Flszbein, A., Opfer, L.A., 1987. The positive and negative syndrome scale (PANSS) for schizophrenia. Schizophr. Bull. 13, 261.

Kirkpatrick, B., Strauss, G.P., Nguyen, L., Fischer, B.A., Daniel, D.G., Cienfuegos, A., Marder, S.R., 2011. The brief negative symptom scale: psychometric properties.

Schizophr. Bull. 37 (2), 300–305.

Klein, D.F., 1984. Depression and anhedonia. In: Clark, D.C., Fawcett, J. (Eds.), Anhedonia and Affect Deficit States. PMA Publishing, New York, pp. 1–14.

Knutson, B., Adams, C.M., Fong, G.W., Hommer, D., 2001. Anticipation of increasing

monetary reward selectively recruits nucleus accumbens. J. Neurosci. 21 (16), RC159.

Kring, A.M., Barch, D.M., 2014. The motivation and pleasure dimension of negative symptoms: neural substrates and behavioral outputs. Eur. Neuropsychopharmacol. 24 (5), 725–736.

Kring, A.M., Gur, R.E., Blanchard, J.J., Horan, W.P., Reise, S.P., 2013. The Clinical Assessment Interview for Negative Symptoms (CAINS):final development and vali- dation. Am. J. Psychiatry 170 (2), 165–172.

Lee, I.A., Preacher, K.J., 2013. Calculation for the Test of the Difference between Two Dependent Correlations with One Variable in Common [computer program].〈http://

quantpsy.org〉.

Lehrl, S., Triebig, G., Fischer, B., 1995. Multiple choice vocabulary test MWT as a valid and short test to estimate premorbid intelligence. Acta Neurol. Scand. 91, 335–345.

Li, Z., Lui, S.S., Geng, F.L., Li, Y., Li, W.X., Wang, C.Y., Tan, S.P., Cheung, E.F., Kring, A.M., Chan, R.C., 2015. Experiential pleasure deficits in different stages of schizo- phrenia. Schizophr. Res. 166 (1–3), 98–103.

Lueken, U., Seidl, U., Schwarz, M., Völker, L., Naumann, D., Mattes, K., Schröder, J., Schweiger, E., 2006. Psychometric properties of a German version of the Apathy Evaluation Scale]. Fortschr. Neurol. Psychiatr. 74, 714.

Marin, R.S., 1991. Apathy: a neuropsychiatric syndrome. J. Neuropsychiatry Clin.

Neurosci. 3 (3), 243–254.

Meehl, P.E., 1962. Schizotaxia, schizotypy, schizophrenia. Am. Psychol. 17, 827–838.

Montgomery, D.C., 2008. Design and Analysis of Experiments. John Wiley & Sons.

Müller, M.J., Marx-Dannigkeit, P., Schlösser, R., Wetzel, H., Addington, D., Benkert, O., 1999. The Calgary Depression Rating Scale for Schizophrenia: development and in- terrater reliability of a German version (CDSS-G). J. Psychiatr. Res. 33, 433–443.

Rosseel, Y., 2012. Lavaan: An R Package for Structural Equation Modeling and More.

Version 0.5–12 (BETA).

Sheehan, D.V., Lecrubier, Y., Sheehan, K.H., Amorim, P., Janavs, J., Weiller, E., Hergueta, T., Baker, R., Dunbar, G.C., 1998. The Mini-International Neuropsychiatric Interview (MINI): the development and validation of a structured diagnostic psychiatric in- terview for DSM-IV and ICD-10. J. Clin. Psychiatry 59, 22–33.

Strauss, G.P., Wilbur, R.C., Warren, K.R., August, S.M., Gold, J.M., 2011. Anticipatory vs.

consummatory pleasure: what is the nature of hedonic deficits in schizophrenia?

Psychiatry Res. 187 (1–2), 36–41.

R Core Team, 2014. R: A Language and Environment for Statistical Computing.

Foundation for Statistical Computing, Vienna, Austria, pp. 2013.

Treadway, M.T., Zald, D.H., 2013. Parsing anhedonia: translational models of reward- processing deficits in psychopathology. Curr. Dir. Psychol. Sci. 22 (3), 244–249.

J.J. Simon et al. Psychiatry Research 260 (2018) 138–143

143