Background. Dysregulation of the striatum and altered corticostriatal connectivity have been associated with psychotic disorders. Social anhedonia has been identified as a predictor for the development of schizophrenia spectrum disorders. The aim of the present study was to examine corticostriatal functional connectivity in individuals with high social anhedonia.

Altered corticostriatal functional connectivity in individuals with high social anhedonia

Experiential pleasure deficits in different stages of schizophrenia.

Very few studies have examined physical and social anhedonia across the spectrum of schizophrenia. In the present study, we recruited three groups of participants (n=84 in each group): patients with schizophrenia, schizotypy and non-schizotypy as assessed by the Schizotypal Personality Questionnaire (SPQ). All participants completed the self-reported trait anhedonia scales (the Revised Physical Anhedonia Scale and the Social Anhedonia Scale). The clinical symptoms of schizophrenia patients were assessed using the Positive and Negative Syndrome Scale (PANSS) and the Scale for Assessment of Negative Symptoms (SANS). We found that the three groups differed in both physical and social anhedonia. The schizotypy group reported higher levels of physical anhedonia than the non-schizotypy group, and the patient group reported higher levels of physical anhedonia than the schizotypy group. For social anhedonia, the non-schizotypy group differed significantly from both the schizotypy and the patient group, while no significant difference was found between the last two groups. Our findings show that individuals with schizotypy exhibits similar social but not physical anhedonia compared with patients with schizophrenia, which further suggests that decreased pleasure experiences in the social environment may be a valuable target for identification and early intervention in high-risk populations.

Individuals with psychometric schizotypy show similar social but not physical anhedonia to patients with schizophrenia

Schizotypy is associated with anhedonia. However, previous findings on the neural substrates of anhedonia in schizotypy are mixed. In the present study, we measured the neural substrates associated with reward anticipation and consummation in positive and negative schizotypy using functional MRI. The Monetary Incentive Delay task was administered to 33 individuals with schizotypy (18 positive schizotypy (PS),15 negative schizotypy (NS)) and 22 healthy controls. Comparison between schizotypy individuals and controls were performed using two-sample T tests for contrast images involving gain versus non-gain anticipation condition and gain versus non-gain consummation condition. Multiple comparisons were corrected using Monte Carlo Simulation correction of p<.05. The results showed no significant difference in brain activity between controls and schizotypy individuals as a whole during gain anticipation or consummation. However, during the consummatory phase, NS individuals rather than PS individuals showed diminished left amygdala and left putamen activity compared with controls. We observed significantly weaker activation at the left ventral striatum during gain anticipation in NS individuals compared with controls. PS individuals, however, exhibited enhanced right ventral lateral prefrontal activity. These findings suggest that different dimensions of schizotypy may be underlied by different neural dysfunctions in reward anticipation and consummation.

Differential mesolimbic and prefrontal alterations during reward anticipation and consummation in positive and negative schizotypy

Data collected through self-report questionnaires are particularly susceptible to inappropriate or random responding, and such invalid data increase noise and attenuate true statistical relationships. While many researchers studying schizotypy have employed infrequency measures to exclude participants, such measures are not universally employed. Moreover, some researchers have even outright questioned whether validity scales are warranted. Here, we show the effect of invalid responses on the relationship between schizotypy and hedonic reaction. For valid responders, negative schizotypal traits were inversely related to both anticipatory and consummatory pleasure (p < .01). Invalid responses were found for 23% of respondents, and within these subjects, no relationship was found between any of the measures. When the valid and invalid respondents were pooled, the relationship was dampened. Furthermore, linear multiple regression modeling showed that validity trended toward moderating the relationship between the variables of interest. These data highlight the importance of screening for, and excluding, invalid responses in schizotypy research. Our results also affirm that screening for random responding is effective and warranted. Implications for future studies employing questionnaire-based methods are discussed.

Invalid responding in questionnaire-based research: implications for the study of schizotypy.

Difficulties in feeling pleasure and expressing emotions are one of the key features of schizophrenia spectrum conditions, and are significant contributors to constricted interpersonal interactions. The current study examined the experience of pleasure and emotional expression in college students who demonstrated high and low levels of schizotypal personality disorder (SPD) traits on self-report questionnaires. One hundred and seventeen subjects with SPD traits and 116 comparison controls were recruited to participate. Cluster analyses conducted in the SPD group identified negative SPD and positive SPD subgroups. The negative SPD group exhibited deficient emotional expression and anticipatory pleasure, but showed intact consummatory pleasure. The positive SPD group reported significantly greater levels of anticipatory, consummatory and total pleasure compared to the control group. Both SPD groups reported significantly more problems in everyday memory and greater levels of depressive and anxiety-related symptoms.

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Ji gang Zong

Papers

Experience of Pleasure and Emotional Expression in Individuals with Schizotypal Personality Features