Background
Schizophrenia is a heterogeneous disorder characterized by cognitive and emotional deficits.
Exploratory or confirmatory factor analyses on various rating scales exploring schizophrenia symptoms have commonly reported at least three symptom dimensions: (1) positive (e.g., hallucinations, delusions); (2) negative (e.g., affective flattening, apathy); (3) disorganized (e.g., formal thought disorders, inappropriate affect [
1].
Schizotypy is a personality organization characterized by traits that are similar to symptoms found in schizophrenia but often in a less severe form and schizotypy is thought to reflect an underlying vulnerability for schizophrenia [
2],[
3]. Schizotypy is a multidimensional construct and the number of dimensions is highly dependent on the rating scales used to assess schizotypal traits.
Bentall et al [
4] underlined that schizotypy scales were developed from three perspectives: symptom-oriented, syndrome-oriented and personality-oriented. In the first approach, individual symptoms were used in the construction of the scales. For example, the Wisconsin schizotypy scales have been developed by the Chapman group using the Meehl manual for schizotypal signs and symptoms.
The Wisconsin schizotypy scales are: physical (PAS) and social anhedonia scales (SanS) [
5], perceptual aberration scale (PerAb) [
6], magical ideation scale (MIS) [
7], impulsive nonconformity scale (INC) [
8], cognitive slippage Scale (CSS) [
9], social fear scale (SF) [
10] and schizotypal ambivalence scale (SAS) [
11].
In the second approach, syndrome-based, schizotypy scales were based on criteria of personality disorders. For example, the Schizotypal Personality Questionnaire (SPQ) [
12] was developed to rate the nine DSM criteria for schizotypal personality disorder: social anxiety, no close friends, constricted affect, paranoia, magical thinking, unusual perceptual experiences, ideas of reference, odd speech, and odd behaviour.
In the third approach using the domain of personality and individual differences several rating scales have been proposed as the Psychoticism subscale [
13] or the Schizophrenia Proneness Scale of the MMPI-2 [
14].
The number of dimensions of schizotypy has been examined by factor studies and a review of the studies [
15] revealed the constant presence of positive and negative dimensions. For example, Kwapil et al [
16] using confirmatory factorial analyses (CFA) on the Wisconsin schizotypy scales (PAS, SanS, PerAb, MIS) in 6137 non-clinical young adults found that the two-factor solution with positive and negative dimensions had the best goodness of fit indices.
When the SPQ was used instead the Wisconsin schizotypy scales three or four structures were found including always a positive (hallucinations, delusions), negative (social anhedonia, anxiety) and disorganization dimensions [
17],[
18].
It is interesting to note that the factorial analyses on the Wisconsin scales did not report a disorganization dimension even when the CSS, measuring cognitive slippage, was included in the design of the study. Only two studies have included the CSS in exploratory factorial analyses of the Wisconsin schizotypy scales.
In 266 undergraduate students Kelley and Coursey [
19], using all the Wisconsin schizotypy scales except the Social anhedonia scale, found a two-factor solution with a first factor representing a general schizotypy dimension and a second factor representing an anhedonia dimension (rated by the Physical anhedonia scale). Yon et al in 399 [
20] university students using the PAS, SanS, PerAb, MIS, CSS and SAS found a two-factor solution with a first factor representing the positive component of schizotypy (PerAb, MIS, CSS, SAS, SanS) and a second factor representing the negative component of the schizotypy (SanS, PAS). In this study the social anhedonia scale loaded on the two factors, the Physical anhedonia scale loaded only on the negative factor and the Cognitive Slippage Scale loaded only on the positive factor.
Thus, disorganization factor was not found in the dimensional structure of the Wisconsin Schizotypy Scales when exploratory factorial analyses were used and to our knowledge no studies have used confirmatory factor analyses on these scales including the Cognitive Slippage scale.
It is interesting to note that two studies [
21],[
22] university or college samples that used CFA on several subscales of the SPQ as well as the SanS, PerAb, MIS and CSS reported a three-factor structure (negative, positive, disorganized). Social anhedonia scale loaded on the negative factor; Magical ideation and perceptual aberration scales loaded on the positive factor and the Cognitive slippage scale loaded on the disorganized factor.
However, as underlined by Kerns and Becker [
23] “few studies have examined the nature of disorganized schizotypy” and only two studies have examined the relationships between disorganized schizotypy and emotional traits.
In the first study ([
21], disorganized schizotypy, measured by the cognitive slippage scale, was found to be associated with increased emotional ambivalence. Ambivalence, defined as reporting simultaneously conflicting emotions in relation to a particular subject, is considered to be one of the main traits in schizophrenia [
24] and schizotypy [
2]. In the study by Kerns [
21], disorganized but not positive schizotypy was associated with emotional confusion, mainly measured by ambivalence, and increased emotionality. In contrast, negative schizotypy including social anhedonia, was associated with increased emotional confusion but decreased emotionality. Moreover, disorganized schizotypy was associated with ambivalence even after removing the variance shared with anhedonia.
In the second study [
23], subjects with disorganized schizotypy significantly differed from control participants in terms of emotional ambivalence measured by the Schizotypal Ambivalence Scale [
25].
To the best of our knowledge, the relationship between disorganized schizotypy and anhedonia has not been previously investigated. Several studies in subjects presenting schizotypal features have indicated that the later onset of psychosis is linked with cognitive disorganization and anhedonia [
26] and a recent follow-up study in 122 non-psychotic subjects investigated the relationship between dimension scores and transition to psychosis during the following 24 months. Scores on the negative (including anhedonia, alogia and disorganized behavior) and disorganization/cognitive dimensions were significantly associated with transition to psychosis [
27].
Moreover, cognitive disorganization in schizotypy is associated with deterioration in visual backward masking [
28]. Several studies have reported that the shine-through visual backward masking paradigm meets the characteristics of an endophenotype for schizophrenia [
28].
However, recent research indicates that anhedonia is not a distinct entity, but can be divided into two distinct components, namely consummatory (or liking) and anticipatory (or wanting) deficit of pleasure (see review in Gard et al, [
29]). Consummatory pleasure refers to the “in the moment” pleasure experienced by the subject directly engaged in an enjoyable activity, whereas anticipatory pleasure refers to the experience of pleasure related to future activities.
For Gard et al [
30] the negative symptoms of schizophrenia could be related to deficits in anticipatory anhedonia. This association between anticipatory anhedonia and negative symptoms has been found also in healthy subjects (Engel et al, [
31]). In subjects presenting negative schizoptypy, defined by elevated social anhedonia, high anticipatory and consummatory anhedonias have been reported comparatively to controls (Martin et al, [
32]; Gooding & Pflum, [
33]).
The present study was therefore designed to investigate the relationship between anhedonia and cognitive disorganization in non-clinical subjects by taking into account firstly the distinction between anticipatory and consummatory anhedonia and secondly emotional ambivalence.
Two different approaches were used. Firstly, dimensional analysis using the Cognitive Slippage scale, schizotypal ambivalence scale and two rating scales measuring anticipatory and consummatory pleasure, was conducted in a large sample of university students. Confirmatory factorial analyses tested the adequacy of various models of disorganized and negative schizotypy. Secondly, categorical analysis was performed using well-defined schizotypy (disorganized or negative) groups and non-schizotypic group based on comparisons on the ambivalence and anhedonia rating scales. Two different samples were examined; the second sample was designed to explore potential replication of the results observed in the first sample.
Given previous studies, we hypothesized firstly that disorganized schizotypy was characterized by ambivalence although negative schizopypy was characterized by anticipatory and consummatory anhedonia and ambivalence.
Competing interests
The authors declare no conflicts of interest in relation to this study.
Authors’ contributions
GL designed the study. AV and JLM conducted the study and collected the data. All authors contributed to and have approved the manuscript.