The Swedish version of the Motivation and Pleasure Scale self-report (MAP-SR): psychometric properties in patients with schizophrenia or depression

Abstract

Purpose

Negative symptoms are commonly regarded as a symptom dimension belonging to schizophrenia spectrum disorders but are also present in depression. The recently developed Clinical Assessment Interview for Negative Symptoms (CAINS) has shown to be reliable and valid. A corresponding self-report questionnaire has also been developed, named the Motivation and Pleasure Scale - Self Report (MAP-SR). The purpose was to evaluate the psychometric properties of the Swedish version of the MAP-SR in patients with either schizophrenia or depression.

Materials and Methods

The MAP-SR was translated to Swedish. Participants were 33 patients with schizophrenia spectrum disorders and 52 patients with a depressive disorder and they completed the MAP-SR, the CAINS and other measures assessing adjacent psychopathology, functioning and cognition.

Results

The internal consistency for the MAP-SR was adequate in both groups (schizophrenia spectrum α = .93, depressive disorder α = .82). Furthermore, the MAP-SR had a large correlation to the motivation and pleasure subscale of the CAINS in patients with schizophrenia disorders (r = −0.75, p < .001), however among patients with depression this correlation was medium-to-large (r = −0.48, p < 0.001).

Conclusions

Findings suggest that the Swedish version of the MAP-SR shows promise as a useful measure of motivation and pleasure, especially in patients with schizophrenia spectrum disorders. Furthermore, results also suggest that the MAP-SR does not assess negative symptoms specifically, but that there is an overlap between depressive and negative symptoms.

Keywords:

• Assessment
• depression
• negative symptoms
• schizophrenia

Introduction

Negative symptoms such as anhedonia, avolition, and blunted affect are viewed as absence of or deficits in normal functioning. While negative symptoms are well recognized in schizophrenia and related conditions they are also evident in depression, especially in severe depression [1]. Antipsychotic medications are effective in reducing positive symptoms such as hallucinations, delusions and disorganization and reduce risk for relapse in acute psychosis [2]. Their effect on negative symptoms is however negligible and finding effective methods to ameliorate negative symptoms have been elucidated as an unmet need in schizophrenia [3]. Furthermore, the assessment of negative symptoms, such as anhedonia, in depression is complicated, in part because the concept has been poorly defined [4]. Measures should also preferably be sensitive to trait versus state aspects of hedonic experience and differentiate anticipatory and consummatory pleasure [5].

In 2005, a consensus conference on negative symptoms was held which resulted in a consensus statement that asserted that negative symptoms in schizophrenia consist of blunted affect, alogia, asociality, anhedonia, and avolition [6]. Furthermore, the consensus statement acknowledged that the current methods of assessing negative symptoms had weaknesses. A workgroup was formed, tasked with developing a new reliable and valid measure of negative symptoms that could be used in research on negative symptoms and in treatment trials [7]. The designated workgroup developed the Clinical Assessment Interview for Negative Symptoms (CAINS) assessing negative symptoms according to the suggested definition including motivation, pleasure, and emotion expression [8]. In the final version, nine items assess motivation and pleasure (MAP) covering anhedonia, avolition, and asociality, and four items assess expression (EXP) covering blunted affect and alogia. During development the CAINS has shown good psychometric properties in schizophrenia spectrum disorders [9–11]. Furthermore, the interview has also been translated to and validated in schizophrenia spectrum samples in German [12], Mandarin and Cantoneese [13], Spanish [14], Korean [15], Serbian (Ristić et al. 2020), and Swedish [16].

While the CAINS was developed with an explicit intention of being easy to administer [8], there are many situations that precludes an extended interview for the assessment of negative symptoms. In such cases, a self-report measure version might be appropriate. For this purpose, a self-report version of the CAINS was developed. This questionnaire was initially called the CAINS-SR and consisted of items covering both the MAP and EXP subscales from the CAINS [17]. However, initial testing of this scale revealed that the items covering the EXP subscale had poor psychometric properties and were removed from the scale. The resulting scale was called the Motivation and Pleasure Scale - Self Report (MAP-SR) and initially consisted of 18 items covering motivation and pleasure. However, during testing 3 items were removed due to poor performance rendering a 15-item scale that showed good internal consistency and convergent validity when compared to the CAINS interview [18]. The final version thus address some of the suggested subdomains of negative symptoms (anhedonia, avolition, and to some extent asociality), but lacks an assessment of blunted affect and alogia. This version of the MAP-SR has also been translated and has shown good psychometric properties in schizophrenia spectrum samples in Spanish [19], Chinese [20] and German [21]. Another self-report measure, the Self-evaluation of Negative Symptoms (SNS), which also includes the domains blunted affect and alogia, have been reported to have good psychometric properties in patients with schizophrenia, and self-assessments are encouraged for further use [22].

In order to establish specificity of the negative symptoms construct, these scales should preferably be investigated also in other populations of patients and in healthy controls [23]. In a review of current assessment methods of anhedonia in depression Rizvi et al. (2016) [5] highlight the MAP-SR as a promising measure also in depression. To our knowledge the psychometric properties of the MAP-SR has not been evaluated in populations with depressive disorders. In a small study, Richter and collegues [24] found that neither the CAINS MAP subscale nor the MAP-SR discriminated between patients with schizophrenia-spectrum disorders and patients with depressive disorders. However, they found that patients with schizophrenia-spectrum disorders had significantly higher scores on the CAINS EXP subscale compared to patients with depressive disorders. Given that anhedonia is a prominent feature of both schizophrenia and depression, but that the question of whether the concept can be treated as the same in both disorders remains largely unanswered, further investigation in this area is warranted.

The purpose of the current study was to investigate the psychometric properties of the Swedish version of the MAP-SR when administered to patients with either a schizophrenia-spectrum disorder or a depressive disorder. Furthermore, we also aimed to explore similarities and differences between these patient groups in correlations between self-reported motivation and pleasure and other outcomes such as clinician-rated negative symptoms and self-reported depression.

Materials and methods

Participants

Participants were patients aged 18–59 at Uppsala University Hospital diagnosed with an ICD-10 schizophrenia-spectrum disorder (n = 33) or an ICD-10 depressive disorder (n = 52) according to case notes and confirmed by interview using the Mini-International Neuropsychiatric Interview (M.I.N.I.; [25]). The participants in the present analysis come from two different studies. A majority (n = 68) participated in a clinical trial and the data retrieved from the trial come from the screening and baseline assessments [26]. The remaining participants (n = 17) comes from a validation study of the of the CAINS interview [16]. For participants in the clinical trial there was an additional inclusion criterion of scoring less or equal than 40 on the MAP-SR. Exclusion criteria were a severe medical condition, epilepsy, metal or cochlear implant in the head, changes in medication in the last month, addiction (illicit drugs or alcohol), pregnancy and insufficient Swedish fluency. All participants provided written informed consent and study procedures were approved by the regional ethical review board and adhere to the ethical principles in the declaration of Helsinki.

Procedure

Data was collected between 2016 and 2020 at the Uppsala University Hospital. Participants completed all assessments during a 4–5 h visit at the clinic where they first completed clinical interviews, laboratory assessments (not reported here) and self-report assessments. Participants in the magnetic stimulation study (n = 68) completed the MAP-SR as part of screening at an inclusion meeting approximately 2 weeks before the remaining assessments. Some of the 17 participants not participating in the clinical trial (all schizophrenia-spectrum patients) may have been administered the MAP-SR after completing the CAINS interview due to practical reasons and the potential effect this may have had on the correspondence between self-reported and interview-based assessment of motivation and pleasure has been explored below. All interviewers (JB, MC, RB) participated in training in conducting the CAINS and the Brief Psychiatric Rating Scale (BPRS).

Materials

The CAINS was translated to Swedish by two of the authors (JB and RB). A back-translation to the original language was provided by a professional translator and this version was approved by the originators. The Swedish version of the CAINS was then used as guidance to translate the MAP-SR to Swedish so that concepts in English that had been translated in a certain way to Swedish for the CAINS, was translated in the same manner also for the MAP-SR. The current version of the MAP-SR includes six items that assess consummatory and anticipatory pleasure related to social, recreational and work domains. Three items assess motivation and drive to spending time together or being in contact with family, friends and/or romantic partners. The remaining six items assess motivation and effort to engage in activities. All items are rated on a 5-point Likert scale and a higher score indicates more motivation and pleasure [18]. See Appendix I for the Swedish version.

Correlations between the MAP-SR and the CAINS were investigated using both the full CAINS interview and the subscales of MAP and EXP. As a comparison with other symptom domains we used the subscales of the BPRS [27] including the negative symptoms subscale (items Blunted affect, Emotional withdrawal, and Motor retardation), the positive symptoms subscale (Suspiciousness, Hallucinations, and Unusual thought content) and the affective symptoms subscale (Anxiety, Depression, Suicidality and Guilt), the total score of the Montgomery Asberg Depression Rating Scale – Self Rated (MADRS-S [28]), two items (Lassitude and Inability to feel) from the MADRS-S, self-rated health with the EQ-5D [29], and the Clinical Global Impression scale (CGI: [30]). Relations to other non-symptom-based factors were assessed with the Extrapyramidal Symptoms Rating Scale (ESRS: [31]), self-rated disability assessed with the Sheehan Disability Scale (SDS [32]) and cognitive function assessed with the Animal Naming Test (semantic verbal fluency; [33]) and the Digit Symbol Substitution Test (processing speed [34]).

Statistical analysis

Descriptive statistics were used to explore data in the two subgroups. Parametric tests or non-parametric equivalents were used to test for differences between groups. Cronbach’s alpha was calculated to determine internal consistency for the MAP-SR. Correlation analyses were used for the main analyses and z-tests of the difference between correlation-coefficients in the two groups were conducted. Cohen’s [35] convention was used for interpreting the effect size of correlation coefficients (i.e. 0.1 = small, 0.3 = medium, 0.5 = large). Two patients in the schizophrenia spectrum group did not complete the SDS. Analyses were conducted in jamovi version 2.2.3 and R version 3.6.

Results

Participant characteristics

Demographic and clinical characteristics are presented in Table 1. The schizophrenia spectrum subgroup was older, were predominantly male, had less neuropsychiatric or anxiety comorbidities, and were less likely to be working or studying compared to the depressive disorder subgroup. Participants in the depressive disorder subgroup had significantly lower scores on the MAP-SR indicating a higher degree of impairment in self-reported motivation and pleasure. Probably since half of the participants in the schizophrenia spectrum subgroup did not participate in the transcranial magnetic stimulation trial (n = 17) and hence were not required to have a score ≥ 40 on the MAP-SR, the variance and resulting standard deviation for the MAP-SR was larger in the schizophrenia subgroup compared to the depressive disorder subgroup (Levenés test F = 6.5, p <.05). Results from the CAINS interview also indicated that the depressive disorder subgroup had less motivation and pleasure as indicated by the MAP-subscale, but there was no difference between the groups on the EXP-subscale. Results from the BPRS indicated no difference between groups on the negative symptom subscale. Furthermore, the schizophrenia spectrum subgroup had a higher score on the positive symptoms subscale and the depressive disorder subgroup had a higher score on the affective symptoms subscale. In line with this, the depressive disorder subgroup also had a higher score on the MADRS-S indicating more depressive symptoms. Results also indicated that participants in the depressive disorder subgroup gave a worse clinical impression and had worse self-rated health compared to the schizophrenia spectrum subgroup. There were no differences between subgroups in terms of self-rated disability, extrapyramidal symptoms or verbal fluency. However, the schizophrenia spectrum subgroup had significantly lower processing speed.

Table 1. Demographic and clinical characteristics of the sample.

	Schizophrenia spectrum disorder (n = 33)		Depressive disorder (n = 52)		Chi-2
	N	%	N	%
Females/males	12/21	36/64	28/24	54/46	2.48
Primary diagnosis schizophrenia	22	67	n.a.	n.a.
Primary diagnosis schizoaffective	11	33	n.a.	n.a.
Primary diagnosis unipolar depression	n.a.	n.a.	47	90
Primary diagnosis bipolar (I/II/unspecified)	n.a.	n.a.	5	10
Comorbidity
ADHD	0	0	10	19	7.19**
Autism	0	0	5	10	3.37
Anxiety disorders	4	12	21	40	7.77**
Graduated from high school	28	85	42	81	0.23
Working/studying at least half-time past six months	6	18	32	62	15.4***
Medication
Antipsychotics	33	100	11	21	50.3***
Clozapine	12	36	0	0	22.0***
Antidepressants
SSRI	7	21	13	25	0.16
SNRI	1	3	16	31	9.7**
Other^a	3	9	21	40	9.8**
Mood stabilizer^b	11	33	13	25	0.7
	Mean	SD	Mean	SD	t/U
Olanzapine equivalents (mg/day)^c	14.2	10.0	0.9	2.0	9.4***
Age	40.0	11.0	29.5	9.3	4.7***
BMI	30.3	8.8	26.3	6.6	2.4*
MAP-SR total	31.4	12.8	17.8	8.2	314***
CAINS total	22.2	9.0	29.1	7.6	−3.8***
Motivation and pleasure subscale	15.6	7.3	21.5	5.8	−4.1***
Expression subscale	6.6	3.1	7.7	3.9	−1.3
BPRS total score	41.3	9.6	49.8	7.3	394***
Negative subscale^d	8.0	2.8	9.2	3.1
Positive subscale^e	6.0	4.1	3.5	1.5	536***
Affective subscale^f	9.0	2.8	17.4	4.4	−8.9***
CGI score	3.9	1.0	4.9	0.8	−4.9***
MADRS-S total	14.9	7.7	30.0	7.7	−8.8***
MADRS-S anhedonia^g	4.2	3.1	7.4	2.4	−5.3***
EQ-5D	64.0	21.1	34.3	15.6	7.4***
SDS	20.1^‡‡	20.2	17.6	7.5	643
ESRS	1.4	2.1	0.6	1.3	704
Animal Naming Test	21.9	6.2	23.9	6.2	−1.4
Digit Symbol Substitution	36.9	15.3	50.0	18.3	−3.4***

Note: SD = Standard Deviation, BMI = Body Mass Index, MAP-SR = Motivation and Pleasure Scale-Self Report, CAINS = Clinical Assessment Interview for Negative Symptoms, BPRS = Brief Psychiatric Rating Scale, CGI = Clinical Global Impression, MADRS-S = Montgomery Asberg Depression Rating Scale self-rating, EQ-5D = EuroQol Group Visual Analogue Scale, SDS = Sheehan Disability Scale, ESRS = Extrapyramidal Symptom Rating Scale, ADHD = Attention Deficit and Hyperactivity Disorder, SSRI = selective serotonin reuptake inhibitor, SNRI = serotonin and norepinephrine reuptake inhibitors.

^a Including mirtazapine, vortioxetine, bupropion, agomelatine or tricyclic antidepressants.

^b Of which lithium 10/85. Mood stabilizers includes lithium, lamotrigine or valproic acid.

^c Ref. [36].

^d Negative symptoms subscale comprises items Blunted affect, Emotional withdrawal and Motor retardation.

^e Positive symptoms subscale comprises items Suspiciousness, Hallucinations and Unusual thought content.

^g Sum of items Lassitude and Inability to feel.

^‡‡ n = 31.

* p<.05.

** p<.01.

*** p<.001.

Internal consistency

As is evident from Table 2, the internal consistency for the MAP-SR was good in the schizophrenia spectrum subgroup. All items except items 7 and 8 showed medium to large item-rest correlations. In the depressive disorder subgroup the internal consistency for the MAP-SR was adequate. Items 7, 8, and 13 had small item-rest correlations.

Table 2. Internal consistency for the MAP-SR.

	Schizophrenia spectrum disorder (n = 33)				Depressive disorder (n = 52)
	Mean (SD)	α	α If item dropped	Item-rest corr.	Mean (SD)	α	α If item dropped	Item-rest corr.
Full scale	31.4 (12.8)	.93			17.8 (8.20)	.82
Item 1	2.58		.92	.60	1.54		.80	.61
Item 2	2.09		.92	.72	1.19		.80	.66
Item 3	2.30		.92	.77	1.29		.80	.67
Item 4	2.33		.92	.77	1.42		.80	.63
Item 5	2.12		.92	.89	1.06		.81	.42
Item 6	2.30		.92	.89	1.33		.80	.55
Item 7	2.67		.94	.11	1.90		.83	.20
Item 8	1.24		.94	.26	1.25		.83	.20
Item 9	2.12		.93	.60	1.39		.81	.39
Item 10	2.06		.92	.81	0.71		.80	.64
Item 11	2.09		.92	.73	1.37		.81	.49
Item 12	1.76		.92	.70	0.56		.81	.44
Item 13	1.58		.92	.67	1.08		.83	.21
Item 14	2.18		.92	.73	0.65		.81	.42
Item 15	1.94		.92	.73	1.10		.81	.46

Note: MAP-SR = Motivation and Pleasure Scale – Self Report, SD = Standard Deviation.

Correlations with symptom and non-symptom domains

See Table 3 for all coefficients. There was a large correlation between the MAP-SR and the CAINS total scale in the schizophrenia spectrum group. However, while the correlation between the MAP subscale of the CAINS and the MAP-SR was large, the correlation between the EXP subscale and the MAP-SR was medium and not significant. This pattern was similar in the depressive disorder subgroup while the correlations were medium sized for the CAINS total scale, medium-to-large for the MAP subscale, and about zero for the EXP subscale. Comparing correlations between groups, only the correlation between the MAP-SR and the CAINS total scale was significantly weaker in the depressive disorder subgroup while the test of difference for the correlations with the MAP and EXP subscales were not significant. However, it should be noted that the difference between groups for the correlation coefficient between MAP-SR and CAINS MAP was borderline significant (Z value at 1.95 while the critical value for p < .05 is 1.96).

Table 3. Correlations between the MAP-SR and various symptom domains.

	MAP-SR
	Schizophrenia spectrum disorder (n = 33)	Depressive disorder (n = 52)	Test of difference (Z)
CAINS
Total	−0.73***	−0.37**	2.33*
MAP	−0.75***	−0.48***	1.95
EXP	−0.34	−0.004	1.51
BPRS
Positive^a	.12	−0.03	0.65
Negative^b	−0.33	−0.07	1.18
Affective^c	−0.13	−0.07	0.87
MADRS-S	−0.70***	−0.53***	1.2
MADRS-S anhedonia^d	−0.89***	−0.55**	3.47***
CGI	−0.52**	−0.47***	0.29
EQ-5D	.73***	.32*	2.58**
ESRS	−0.01	−0.19	0.79

Note. MAP-SR = Motivation and Pleasure Scale – Self Report, CAINS = Clinical Assessment Interview for Negative Symptoms, MAP = motivation and pleasure subscale, EXP = expression subscale, BPRS = Brief Psychiatric Rating Scale, MADRS-S = Montgomery Asberg Depression Rating Scale self-rating, CGI = Clinical Global Impression, ESRS = Extrapyramidal Symptom Rating Scale.

^a Positive symptoms subscale comprises items Suspiciousness, Hallucinations and Unusual thought content.

^b Negative symptoms subscale comprises items Blunted affect, Emotional withdrawal and Motor retardation.

^c Affective symptoms subscale comprises items Anxiety, Depression, Suicidality and Guilt.

^d Sum of items Lassitude and Inability to feel.

* p<.05.

** p<.01.

*** p<.001.

Between the MAP-SR and the BPRS negative subscale there was a medium but non-significant correlation in the schizophrenia spectrum subgroup and in the depressive disorder subgroup this correlation was close to zero. For the BPRS positive and affective subscales, there were small or close to zero and non-significant correlations with the MAP-SR in both groups. There were no differences between groups in terms of these correlations. Not shown in Table 3, we also tested the correlations between the CAINS subscales and the BPRS negative subscale. The correlations between the CAINS-EXP and the BPRS negative subscale were .87 (p<.001) in the schizophrenia spectrum group and .84 (p<.001) in the depression group, while the correlations between the CAINS-MAP subscale and the BPRS negative subscale were .37 (p < .05) in the schizophrenia group and .16 (p = .26) in the depression group. For the MADRS-S there were large correlations with the MAP-SR in the two diagnostic subgroups and no significant difference between groups.

Also presented in Table 3, there were large correlations between the MAP-SR and the two anhedonia items from the MADRS-S in the two subgroups while the correlation in the depressive disorder subgroup was significantly smaller according to the test of difference. In addition, there were large to medium sized negative correlations between the MAP-SR and the CGI in the in the two subgroups. For the EQ-5D there was a large correlation with the MAP-SR in the in the schizophrenia spectrum subgroup while this correlation was medium sized in the depressive disorder subgroup. The test of difference of correlations between subgroups was also significant. There were no significant correlations between the MAP-SR and the Extrapyramidal Symptom Rating Scale.

Furthermore, as some of the schizophrenia spectrum patients not included in the clinical trial may have been administered the MAP-SR after completing the CAINS interview, we also tested if this may have influenced the results. Results presented in Table S1 in the Supplement indicate that correlations between the MAP-SR and CAINS total and MAP subscales were of similar magnitude. The correlation between the MAP-SR and CAINS EXP subscale seemed to be stronger among patients not included in the trial but this failed to reach significance.

Correlations between the MAP-SR and non-symptom domains are presented in Table 4. There were no significant correlations between the MAP-SR and the Sheehan Disability Scale, the Animal Naming Test or the Digit Symbol Coding Test.

Table 4. Correlations between the MAP-SR and non-symptom domains.

	MAP-SR
	Schizophrenia spectrum disorder (n = 33)	Depressive disorder (n = 52)	Test of difference (Z)
SDS	−0.04^‡	.07	0.46
Animal Naming Test	.13	.04	0.74
Digit Symbol Substitution	−0.06	−0.04	0.09

Note: SDS = Sheehan Disability Scale.

^‡ n = 31.

* p < .05.

Discussion

The purpose of this study was to evaluate the Swedish version of the MAP-SR, a self-report questionnaire assessing motivation and pleasure, a domain of negative symptoms. The main finding is that the MAP-SR had a large correlation with the MAP subscale of the CAINS but no significant correlation with the EXP subscale of the CAINS in the schizophrenia spectrum subgroup, and a medium-to-large correlation with the CAINS MAP and no correlation with the CAINS EXP in the depressive disorder subgroup. Overall, these results are in accordance with findings using the original version of the MAP-SR [18], the German version [21], the Chinese version [20] and the Spanish version [19]. Previous investigations have found that the MAP-SR correlates with measures of role functioning [18] but not functional capacity per se [18], and only weakly with global assessment of functioning (GAF: [21]). In the current study we found that the MAP-SR did not correlate with the Sheehan Disability Scale but that it correlated with the Clinical Global Impression Scale, both in patients with schizophrenia spectrum disorders and in patients with depressive disorders. We also found associations between the MAP-SR and self-rated health with the EQ-5D, and this association was particularly strong among patients with schizophrenia spectrum disorders. We found no correlation between the MAP-SR and the ESRS and no strong associations with Animal Naming or Digit Symbol Substitution suggesting minimal overlap between self-reported motivation and pleasure and neither extrapyramidal symptoms nor measures of cognitive functioning.

This is one of the first studies testing the MAP-SR among patients with a depressive disorder. Anhedonia is a common issue in depression and the MAP-SR could be a useful tool both in research and clinical care with these patients. We found that patients with a depressive disorder had less motivation and pleasure as measured with the MAP-SR compared to patients with schizophrenia-spectrum disorders. In both groups there were significant correlations between the MAP-SR and clinician rated motivation and pleasure (CAINS MAP) and self-reported depression (MADRS-S). However, results indicated that the relationship between the MAP-SR and both clinician rated motivation and pleasure and self-reported anhedonia (MADRS-S) was weaker in patients with depressive disorders compared to patients with schizophrenia spectrum disorders. Richter et al. (2019) [24] also administered the MAP-SR to patients with depressive disorders. In contrast to the current findings, they found no significant difference between patients with schizophrenia spectrum disorders and patients with depressive disorders on the MAP-SR. A study using another self-report scale for negative symptoms (the SNS) could not differentiate between schizophrenia and depression either [37].

Despite overall satisfactory internal consistency both items 7 (importance of family relationships) and 8 (importance of partner relationships) of the MAP-SR showed poor item-rest correlations in both subgroups. Item 7 had the highest mean in both groups suggesting that importance of family may be less affected by reduced motivation and pleasure. For item 8, there was no salient pattern. Furthermore, item 13 (effort at work or school), showed poor item-rest correlation in the depressive disorder subgroup but not in the schizophrenia disorder subgroup suggesting that this domain may be less related to underlying deficits in motivation and pleasure in the depressive disorder population.

In this study we found the MAP-SR to be correlated with self-rated symptoms of depression as assessed with the MADRS-S. This is not in accordance with the original investigations on the MAP-SR [17, 18] or the validation of the Chinese version [20] as these studies found that the MAP-SR did not correlate with the clinician administered Calgary Depression Scale for Schizophrenia. However, the current results are in line with those of Engel and Lincoln (2016) [21] who found a moderate correlation between the MAP-SR and self-reported symptoms of depression with the BDI-II. Taken together this points to accumulating evidence suggesting that the relationships between self-reported motivation and pleasure and with clinician assessed and self-reported symptoms of depression respectively, might be different. One source for this difference could be common method bias but it could also be that the subjective experience of motivation and pleasure is similar or shares more overlap with the subjective experience of depression. In the current study, the correlation between the MAP-SR and the CAINS-total scale, as well as the correlation between the MAP-SR and the two anhedonia items from the MADRS-S, were significantly stronger in the schizophrenia spectrum subgroup compared to the depressive disorder subgroup. This suggests that the validity for the MAP-SR is stronger in the schizophrenia spectrum subgroup. However, in both subgroups, the correlation between the MAP-SR and the total scale of the MADRS-S was strong, suggesting considerable overlap between constructs. Unfortunately, the current study did not include a clinician administered assessment of depression and more research is needed to further elucidate these relationships both in schizophrenia spectrum disorders and in depressive disorders.

As a result from the consensus conference in 2005 the definition and operationalization of negative symptoms was broadened. When using the CAINS to assess negative symptoms the interviewer asks the patient about his or her experience regarding motivation and pleasure regarding social relationships, work/school, and recreational activities in addition to observing and assessing facial and vocal expression, expressive gestures and quantity of speech. Prior methods for assessing negative symptoms (e.g. PANSS and BPRS) are mainly based on these latter observations. Research suggests that this broadened definition and assessment of negative symptoms consist of two factors: motivation and pleasure corresponding to the items where the interviewer asks the patient about social relationships, work/school and recreation, and experience corresponding to the items where the interviewer observes the patient’s behavior during the interview [38]. In the current study, there was a strong correlation between the BPRS negative subscale and the CAINS EXP-subscale in both patient groups while the correlation between the BPRS negative subscale and the CAINS MAP-subscale was weaker in both groups and non-significant in the depression group, which arguably further supports the notion of two distinct factors of negative symptoms. Furthermore, there was no significant correlation between the MAP-SR and BPRS negative subscale in either group. During the development of the MAP-SR it was evident that patients had difficulties in rating their own expressional deficits when comparing these to interviewer-based assessments [17]. However, accumulating evidence suggests that they can rate their own experience of motivation and pleasure that corresponds well with assessor-based methods and our current results support this notion in a Swedish context. However, our current results also implicate that the MAP-SR correlate strongly with other self-reported constructs such as depression and self-rated health. As such we tentatively conclude that while self-reported motivation and pleasure with the MAP-SR seem to correspond adequately to interview-based assessment of motivation and pleasure it also seems to capture significant variance in other constructs related to mental health which should be kept in mind when using and interpreting the scale. Furthermore, in the current study we assessed self-reported motivation and pleasure in both schizophrenia-spectrum disorders and in depressive disorders in a Swedish context. Reduced motivation and pleasure are important facets of both types of psychopathology, however it should be noted that the current study was not designed to address questions regarding similarities or differences in the possible mechanisms underlying motivation and pleasure and whether these are overlapping or distinct (or perhaps both) in the two patient groups [39]. Notwithstanding, and even though the MAP-SR and CAINS were developed to assess negative symptoms in schizophrenia, our current investigation suggest that the MAP-SR captures important subjective perception of motivation and pleasure and that this correlates to other related constructs also in patients with depressive disorders.

This study has several limitations. First, the sample size was relatively small, especially for the schizophrenia spectrum subgroup, which may weaken the robustness of the results. Despite this, our results were generally in line with previous investigations which arguably decreases concerns with type I errors. Second, results indicate that the depressive disorder subgroup was significantly younger, had more clinician assessed negative symptoms, less self-reported motivation and pleasure and gave a significantly worse clinical impression compared to the schizophrenia spectrum subgroup. This suggests that patients in the schizophrenia spectrum subgroup tended to be in a relatively less severe state related to their mental illness while patients in the depression group tended to be in a more severe state related to their mental illness, which should be kept in mind when interpreting the results. Furthermore, probably due to the inclusion criteria, the variance for the MAP-SR was larger in the schizophrenia subgroup, as half of these participants did not participate in the magnetic stimulation trial that required scoring ≥ 40, and this may have contributed to the larger correlations rather than actual differences between populations. Additionally, for a majority of the participants the MAP-SR was administered approximately two weeks before the remaining items and the current study did not include an assessment of test-retest reliability. If the MAP-SR was not temporally stable in the current study the estimates presented could be compromised. However, previous investigations on the MAP-SR that have assessed the temporal stability of the full scale suggests that the 4 week test-retest reliability is excellent with an ICC of 0.98 [20], but we cannot rule out that factors or events during this two-week period could have influenced the obtained results. Furthermore, the lack of repeated assessment and test-retest reliability precludes from any estimation of meaningful change or difference in the MAP-SR which arguably is an important aspect of questionnaire development and validation. Also, some of the patients not included in the clinical trial may have been administered the MAP-SR after completing the CAINS interview. Consequently, some of these participants may have been primed or influenced during the interview which may have affected their responses on the MAP-SR and thus increased the risk of inflating the correspondence between the two assessments. However, we explored if there were any differences between schizophrenia spectrum patients included and not included in the trial which revealed no difference in the correlation between self-reported and interviewer-based assessment of motivation and pleasure. Finally, an additional limitation when studying the MAP-SR is the inherent lack of an assessment of the negative symptom subdomains blunted affect and alogia. An alternative measure such as the SNS [22], which is designed to also capture these two domains, may be a more comprehensive measure of self-reported negative symptoms.

Despite limitations, the current study finds that the MAP-SR is a promising measure of self-reported motivation and pleasure in a Swedish language context. The results suggest that the correspondence between self-reported and clinician rated motivation and pleasure is strong among patients with schizophrenia, while weaker but still substantial among patients with depression. As such, it corroborates its potential for assessing patients’ subjective experience of motivation and pleasure, which is often affected in the schizophrenia spectrum and in depression. This is a valuable addition both in research and in clinical work, not only for general assessment but potentially also for monitoring patient progress and recovery. Furthermore, this study also corroborates earlier findings concerning the overlap between negative symptoms and depressive symptoms and differential relationships depending on whether the assessment is self-report or made by a clinician. To further elucidate these relationships, more research is needed with adequate sample sizes including both self-reported and interview-based assessment of negative and depressive symptoms comparing patients with schizophrenia spectrum disorders, depressive disorders and healthy controls.

Disclosure statement

The authors report that there are no competing interests to declare.

Data availability statement

Due to the nature of this research, participants of this study did not agree for their data to be shared publicly, so supporting data is not available.

Additional information

Funding

RB was supported by the Swedish Research Council Grant 2016–02362. JB was supported by the Lennander Foundation. The study was also supported by unrestricted grants from the Märta and Nicke Nasvell Foundation and the Professor Bror Gadelius Foundation.