Anhedonia in prolonged schizophrenia spectrum patients with relatively lower vs. higher levels of depression disorders: Associations with deficits in social cognition and metacognition

This study has sought to explore whether there are at least two subtypes of anhedonia in schizophrenia: one closely linked with depression and another that occurs in the absence of depression which is related to a general paucity of internal experience. Participants were 163 adults with schizophrenia who completed assessments of depression, anhedonia, executive functioning, positive and negative symptoms, social cognition and metacognition. A cluster analysis based on participants’ depression and anhedonia symptom scores produced three groups: High Depression/High Anhedonia (n = 52), Low Depression/Low Anhedonia (n = 52), and Low Depression/High Anhedonia (n = 59). An ANCOVA and post hoc comparisons controlling for positive and negative symptoms found that the Low Depression/High Anhedonia group had poorer metacognition and social cognition than other groups. These findings point to the possibility of a subtype of anhedonia in schizophrenia, one occurring in the relative lesser levels of depression, and tied to deficits in the ability to think about oneself and others.     

Magnitude,timing and duration of mood state and cognitive effects of acute moderate exercise in major depressive disorder

BackgroundAcute exercise generally improves mood state and cognitive functioning in healthy adults. However, the impact of acute exercise on primary symptoms in adults with major depressive disorder (MDD) is poorly understood. The present randomized cross-over study evaluated the magnitude, timing, and duration of the psychological effects of 30 min of moderate-intensity cycling exercise compared to quiet rest in 30 adults (21 female) with MDD.MethodsDepressed mood state (Profile of Mood States Short Form-Depression; POMS-D), state anhedonia (anhedonia Visual Analog Scale [VAS], and Dimensional Anhedonia Rating Scale [DARS]), and cognition (inhibition via Stroop and working memory via the 2-back task) were assessed pre, mid, post, 25-, 50- and 75-min after each session.ResultsGeneralized estimating equations demonstrated significant session by time interactions for POMS-D and VAS indicating small-to-large improvements in mood state and anhedonia up to 75 min post-exercise (p < 0.05; Cohen’s d ranges: POMS [-0.69, -0.95]; DARS, [-0.02, 0.16]; VAS [0.33, 0.83]) with greater immediate effects that lessened somewhat across time. For cognition, Stroop reaction time improved during exercise, but was worse at 25- and 50-min post-exercise compared to quiet rest (p < 0.05); no differences were found for 2-back reaction time.LimitationsThe small sample and continued psychological effects at 75 min indicate a potentially longer-lasting response than was measured herein.ConclusionPerforming short bouts of moderate intensity exercise appears to be effective for management of key symptoms (anhedonia, depressed mood state) in adults with MDD. The time immediately post-exercise may be ideal for performing emotionally challenging tasks and/or tasks where a low symptom severity would be helpful (e.g., psychotherapy).     

Trait anhedonia is a transdiagnostic correlate of internalizing problems during adolescence

Developmental research documents that anhedonia, or diminished interest in usual activities, is associated with a diverse array of emotional problems in childhood and adolescence. Meanwhile, official nosologies desginate anhedonia as a more specific characteristic of major depressive disorder. Using a quantitative model of the internalizing domain, we compared the strength of transdiagnostic versus diagnosis-specific pathways from anhedonia to major depression (and other internalizing conditions) during adolescence. We recruited 241 youth ages 14–17 who completed semistructured interviews of anxiety and depressive disorders, as well as several self-report surveys of trait anhedonia and neuroticism. Confirmatory factor analysis of diagnostic correlations revealed good fit for a unidimensional model of the 10 internalizing conditions we assessed. This overarching internalizing dimension was statistically significantly correlated with trait anhedonia (r = 0.17) and neuroticism (r = 0.59). In contrast, anhedonia was virtually unrelated to major depression (r = −0.02), net the internalizing dimension. Thus, in this sample, the connection between anhedonia and major depression was explained by a transdiagnostic dimension presumed to underlie all internalizing problems. Compared to neuroticism, however, anhedonia had a more limited association with internalizing, consistent with established personality models of anxiety and depression. We conclude that these data are consistent with conceptualizing anhedonia predominantly as a transdiagnostic correlate of internalizing conditions, rather than a specific marker of major depression, in developmental psychopathology research and clinical interventions for young people.     

Increased perceived stress is associated with blunted hedonic capacity: potential implications for depression research

Preclinical studies suggest that stress exerts depressogenic effects by impairing hedonic capacity; in humans, however, the precise mechanisms linking stress and depression are largely unknown. As an initial step towards better understanding the association between stress and anhedonia, the present study tested, in two independent samples, whether individuals reporting elevated stress exhibit decreased hedonic capacity. The Perceived Stress Scale (PSS) measured the degree to which participants appraised their daily life as unpredictable, uncontrollable, and overwhelming. Hedonic capacity was objectively assessed using a signal-detection task based on a differential reinforcement schedule. Decreased reward responsiveness (i.e., the participants' propensity to modulate behavior as a function of reward) was used as an operational measure of hedonic capacity. In both Study 1 (n=88) and Study 2 (n=80), participants with high PSS scores displayed blunted reward responsiveness and reported elevated anhedonic symptoms. Additionally, PSS scores predicted reduced reward responsiveness even after controlling for general distress and anxiety symptoms. These findings are consistent with preclinical data highlighting links between stress and anhedonia, and offer promising insights into potential mechanisms linking stress to depression.     

Understanding anhedonia in schizophrenia through lexical analysis of natural speech

Anhedonia is a negative prognostic indicator in schizophrenia. However, the underlying nature of this emotional deficit is unclear. Laboratory studies examining patients’ emotional reactions under controlled circumstances have failed to find evidence for a diminished hedonic response, instead finding that patients’ reactions to laboratory stimuli are characterised by high levels of negative emotion. The present study employed lexical analysis of natural speech in 52 patients and 49 non-patient controls while they discussed separate neutral, pleasant and unpleasant autobiographical memories. Patients with clinically rated anhedonia, versus other patients and controls, showed a dramatic increase in negative emotion expression when discussing pleasurable memories, but they showed no corresponding decrease in positive emotion. These findings provide further evidence that “anhedonia” is more reflective of negative emotional states than the absence of positive ones. These findings also raise questions about how positive and negative emotions can be simultaneously co-activated in patients with schizophrenia.     

Anticipatory and consummatory components of the experience of pleasure: A scale development study

The Temporal Experience of Pleasure Scale (TEPS) was designed to measure individual trait dispositions in both anticipatory and consummatory experiences of pleasure. From an initial pool of theory-based items, we developed a 10-item anticipatory pleasure scale and an 8-item consummatory pleasure scale using several large college-age samples; the two scales were both internally consistent and temporally stable. As expected, these two scales were moderately, positively correlated with each other. Examination of convergent and discriminant validity indicated that the two scales measured distinct and specific constructs. In particular the anticipatory scale was related to reward responsiveness and imagery, while consummatory pleasure was related to openness to different experiences, and appreciation of positive stimuli. Potential applications of the TEPS, particularly in psychopathology research, are discussed.     

Investigating the dynamics of affect: Psychological mechanisms of affective habituation to pleasurable stimuli

Affective habituation (i.e., reductions in stimulus-evoked affective reactions as a result of previous exposure) may serve a functional purpose. However, little is know about the psychological mechanisms underlying this process. To elucidate the characteristics of affective habituation, two experiments that examined affective reactions to repeated exposures of pleasurable stimuli were conducted. Results of these experiments indicated that habituation trajectories are characterized by linear decreases in affect. Results also demonstrated that habituation can be slowed by the introduction of novel stimuli (i.e., “novelty effects”), effects that are dimensional (rather than taxonic) in nature. Experiment 2 demonstrated that habituation is mediated by conceptual rather than perceptual processes. Depressed and anhedonic individuals were not more susceptible to habituation in either experiment. The current findings and previous theorizing suggest that habituation may be an important component of an adaptive affective processing system that promotes effective responses to salient stimuli and prevents compulsive reward-seeking behavior.

Anhedonia and emotional numbing in combat veterans with PTSD

We explored relationships between anhedonia and posttraumatic stress disorder (PTSD) symptom clusters, including their role in predicting psychiatric comorbidity. Our measure of anhedonia was derived from an examination of the latent structure of the Beck Depression Inventory. We found evidence for a two-factor solution, leading to anhedonia and undifferentiated, global depressive symptoms scales. In primary analyses, anhedonia had a unique positive relationship with PTSD's emotional numbing symptoms and minimal relationships with other PTSD symptoms. Upon examining the incremental validity of appetitive functioning (i.e., anhedonia, emotional numbing) over and above aversive functioning (i.e., re-experiencing, avoidance, and hyper-arousal PTSD symptoms) variables, greater emotional numbing increased the likelihood of being diagnosed with a major depressive disorder, and greater anhedonia increased the likelihood of being diagnosed with additional anxiety disorders and to a lesser extent, psychotic disorders. Results were consistent with research on the distinction of appetitive and aversive functioning, providing insight into the nature of PTSD.     

Metacognition and emotion – How accurate perception of own biases relates to positive feelings and hedonic capacity

Metacognition refers to awareness of one’s own cognitive processes, including examining own biases and decision making. Metacognitive self (MCS), defined as accuracy in perception of own biases, is associated with pro-health behaviors and desire for feedback, including negative information.Two studies investigated MCS in relation to emotion and hedonic capacity. First, in a longitudinal study of college students, MCS measure was stable over time, and correlated with feelings of love and joy. In the second study, MCS, mood, and hedonic capacity ratings were collected prior to evaluating stimuli for pleasure from engagement during an fMRI. Higher MCS was associated with greater hedonic capacity and increased signal in cortical areas involved in self-reflection and decision making.Our findings implicate self-awareness of biases as a cognitive process supporting positive emotional state and hedonic capacity. Future studies should explore how MCS relates to changes in mood and vulnerability to mood disorders.