Association of Cognitive Impairment With Anhedonia in Patients With Schizophrenia

Anhedonia is considered as one of the five dimensions of negative symptoms and mainly refers to the reduction of the capacity of feeling pleasure. Increasing evidence suggests that anhedonia in schizophrenia may be partly explained by cognitive impairment. However, the associations between specific cognitive impairment and anhedonia are not fully investigated. The purpose of this study was to examine anticipatory anhedonia, consummatory anhedonia, and their cognitive associations in schizophrenia. A total number of 100 patients with schizophrenia and 67 healthy volunteers were recruited. The clinical symptoms of schizophrenia were assessed. Anticipatory pleasure, consummatory pleasure, and cognitive functions of each participant were measured. Multiple linear regression analysis was performed to investigate the influencing factors of anhedonia in schizophrenia. The results showed no significant differences in sex, age, education year, body mass index (BMI), and marital status between the schizophrenia group and healthy control group (all P > 0.05). Both anticipatory and consummatory pleasure in the schizophrenia group were significantly lower than those in the healthy control group (all P < 0.05). Immediate memory, visual spanning, language, attention, and delayed memory were significantly poorer in the schizophrenia group (all P < 0.05). The results showed that language deficit is an independent risk factor for anticipatory anhedonia (B' = 0.265, P = 0.008, 95% CI: 0.038-0.244), while delayed memory deficit is an independent risk factor for consummatory anhedonia (B' = 0.391, P < 0.001, 95% CI:0.085-0.237). To the best of our knowledge, this is the first study that reported the specific cognitive associations of anhedonia in schizophrenia. The findings have added new evidence on the influencing factors of anhedonia and provided clues for the associations between clinical manifestations of schizophrenia.

Adrenergic Attenuation of Immune Activity is Associated with Anhedonia in Adolescents

While inflammation has been implicated in the manifestation of psychiatric symptoms, the role of immune attenuation via sympathetic modulation in psychopathology remains unclear. Here, this study aimed to assess β2-agonist clenbuterol (CBL) as a promising agent to model adrenergic-induced immune response following ex vivo immune activation with lipopolysaccharide (LPS). Relationships between CBL-modulated cytokine levels and symptom measures were then explored. Adolescents were evaluated with semi-structure interviews and self-reported depression, anxiety, and anhedonia levels. Fasting whole-blood samples were collected and stimulated with LPS in the presence and absence of CBL for 6 hours, with supernatants being subjected to Luminex multiplex assay for 41 cytokines. Cytokine levels between conditions were compared using Bonferroni-corrected nonparametric tests. Exploratory factor analysis reduced 41 cytokines into fewer factors in each experimental condition, and their relationships with psychiatric symptoms were examined with Spearman correlations controlling for age, sex, and BMI. Data from 130 participants (15.25 ± 2.16 years old, 59% female) were analyzed. 10 cytokines were significantly affected by CBL treatment compared to LPS alone. LPS+CBL factor 3 significantly correlated with both anticipatory (rho = -0.39, p = 7.4 × 10-5) and consummatory anhedonia (rho = -0.36, p = 3.3 × 10-4), and these correlations remained significant when controlling additionally for depression. There were no significant associations between immune factors with depression or anxiety severity. Findings support our hypothesis that clenbuterol attenuates inflammatory effects thought to underlie psychiatric conditions in youth. Using a data-driven analytic method, distinctive relationships between CBL-affected cytokines and dimensional anhedonia were reported, further elucidating the role of β2-agonism in adolescent affective symptomatology.

Dopamine dysregulation hypothesis: the common basis for motivational anhedonia in major depressive disorder and schizophrenia?

Abnormalities in reward processing are crucial symptoms of major depressive disorder (MDD) and schizophrenia (SCH). Recent neuroscientific findings regarding MDD have led to conclusions about two different symptoms related to reward processing: motivational and consummatory anhedonia, corresponding, respectively, to impaired motivation to obtain rewards (‘wanting’), and diminished satisfaction from consuming them (‘liking’). One can ask: which of these is common for MDD and SCH. In our review of the latest neuroscientific studies, we show that MDD and SCH do not share consummatory anhedonia, as SCH patients usually have unaltered liking. Therefore, we investigated whether motivational anhedonia is the common symptom across MDD and SCH. With regard to the similarities and differences between the neural mechanisms of MDD and SCH, here we expand the current knowledge of motivation deficits and present the common underlying mechanism of motivational anhedonia – the dopamine dysregulation hypothesis – stating that any prolonged dysregulation in tonic dopamine signaling that exceeds the given equilibrium can lead to striatal dysfunction and motivational anhedonia. The implications for further research and treatment of MDD and SCH are also discussed.

Possible New Symptoms of Tobacco Withdrawal II: Anhedonia—A Systematic Review

Introduction When animals undergo nicotine deprivation, rewards become less rewarding (ie, anhedonia occurs). We searched for tests of whether anhedonia occurs in abstinent smokers. Methods The major inclusion criterion was a within-participants comparison of behavioral measures of reward sensitivity or self-reported anhedonia during smoking versus during abstinence among daily smokers. A computerized search of PubMed, PsychInfo, and Cochrane databases and other methods located 13 studies. All but one were laboratory studies. Results The number of studies and participants were small and the results mixed. In terms of anticipatory anhedonia (ie, wanting a reward), abstinence appeared to decrease willingness to work for immediately available rewards, but did not appear to influence how much adding rewards to a task increased responding. Abstinence also appeared to produce small increases in self-reported anticipatory anhedonia. In terms of consummatory anhedonia (ie, liking a reward), self-report measures found anhedonia decreased pleasure from rewards in some but not all tests. In terms of learning (ie, learning to choose a more frequent reward), abstinence did not reliably decrease allocating responding to high versus low frequency reward options. Conclusions Although results were mixed, abstinence appears to increase anticipatory anhedonia. It is unclear if abstinence increases consummatory or reward learning-based anhedonia. Further studies of anhedonia in clinical settings are needed (1) to estimate the reliability and clinical significance of anhedonia as a symptom of tobacco withdrawal, (2) to assess if effects represent withdrawal versus offset processes, and (3) to assess if anhedonia interferes with the ability to stop smoking. Implications Anticipatory anhedonia appears to be a symptom of tobacco withdrawal and should be added to tobacco withdrawal checklists and diagnostic criteria. Further study of consummatory and learning-based anhedonia is warranted.

Electrophysiological Correlates of Negative Symptom Domains in Schizophrenia

IntroductionNegative symptoms are a core feature of schizophrenia but their pathophysiology remains elusive. They cluster in a motivation-related domain, including apathy, anhedonia, asociality and in an expression-related domain, including alogia and blunted affect.AimOur aim was to investigate the different neurobiological underpinnings of the two domains using the brain electrical microstates (MS), which reflect global patterns of functional connectivity with high temporal resolution.MethodWe recorded multichannel resting EEGs in 142 schizophrenia patients (SCZ) and in 64 healthy controls (HC), recruited to the Italian network for research on psychoses study. Four microstates (MS) classes were computed from resting EEG data using the K-Mean clustering algorithm. Pearson's coefficient was used to investigate correlations of microstates measures with negative symptom domains, assessed by the Brief Negative Symptoms Scale (BNSS).ResultsSCZ, in comparison to HC, showed increased contribution and duration of MS-C. Only the avolition domain of BNSS correlated with the contribution and occurrence of MS-A. Within the same domain, anticipatory anhedonia, apathy and asociality, but not consummatory anhedonia, were positively correlated with contribution and occurrence of microstate A. Asociality was also negatively correlated with contribution and occurrence of MS-D.ConclusionOur findings support different neurobiological underpinnings of the negative symptom domains, avolition and expressive deficit. Furthermore, our results lend support to the hypothesis that only anticipatory anhedonia is linked to the avolition domain of the negative symptoms. Mixed results in the literature concerning the presence of MS-A and D abnormalities in schizophrenia might be related to the syndrome heterogeneity.Disclosure of interestThe authors have not supplied their declaration of competing interest.