Assessment of Depression in Adults and Youth.

This article selectively reviews the key issues and measures for the assessment of depressive disorders and symptoms in youth and adults. The first portion of the article addresses the nature and conceptualization of depression and some key issues that must be considered in its assessment. Next, the diagnostic interview and clinician- and self-administered rating scales that are most widely used to diagnose, screen for, and assess the severity of depression in adults and youth are selectively reviewed. In addition, the assessment of three transdiagnostic clinical features (anhedonia, irritability, and suicidality) that are frequently associated with both depression and other forms of psychopathology is discussed. The article concludes with some broad recommendations for assessing depression in research and clinical practice and suggestions for future research.

Sucrose preference test: A systematic review of protocols for the assessment of anhedonia in rodents.

Anhedonia is described as a decreased ability to experience rewarding and enjoyable activities, a core symptom of major depressive disorder. The sucrose preference test (SPT) is a widely used and reliable behavioural test to assess anhedonia in rodents, based on a two-bottle choice paradigm. To date, different protocols are in use, inducing variability between researchers and hampering comparisons between studies. We performed a systematic review of the SPT protocols used in 2021 to identify the parameters in which they differ and their potential impact. We searched a total of four databases (PubMed, Scopus, Web of Science and Science Direct), from 1st January 2021 to 31st December 2021, and screened a total of 1066 articles. After screening by title and abstract, a total of 415 articles were included in this review. We extracted and analysed the different procedures used, the type of sweet solution and the habituation, deprivation, and testing protocols. The overall quality of the studies was considered very good, however, SPT protocols were extremely variable between studies with a total of 65 different habituation protocols and 104 combinations of food/water deprivation and preference testing duration. As the SPT is one of the most used tests to assess anhedonia in rodents, this work raises awareness of the great variability in SPT protocols being currently used. Furthermore, we call for standardization in the protocol used, and overall improvement of data reporting of methodologies and results, to increase the consistency between studies and allow a better comparison of results between different labs.

Greater anhedonia scores in healthy individuals are associated with less decline in 24-hour energy expenditure with fasting: Evidence for a link between behavioral traits and spendthrift phenotype.

Obesity rates are increasing and affecting mental health. It is important to understand how behavioral traits such as anhedonia are associated with physiologic traits that may predict weight-change in clinical and non-clinical populations. We studied whether 24-hour energy expenditure (24hEE) changes with fasting and overfeeding are associated with anhedonia in a healthy cohort. We performed behavioral assessments (physical anhedonia scale (PAS) and inventory for depressive symptoms (IDS)) followed by measures of 24hEE and urinary catecholamines in a whole-room indirect calorimeter (respiratory chamber) during energy balance, and then randomly during fasting and 2 different overfeeding diets. Participants (n=98) were medically healthy, between 18 and 55 years of age, with normal glucose regulation and weight-stable 6 months before admission. Women were premenopausal and not pregnant. Higher PAS was significantly associated with lesser decrease in 24hEE with fasting and higher urinary catecholamine excretion rates - consistent with spendthrift metabolism. As IDS increased, the association between anhedonia and the change in 24hEE from energy balance to fasting decreased (B-values were lower for change in EE). Here, higher PAS scores may reflect the ability to respond with appropriate homeostatic reactions which balance energy needs. IDS scores blunting this response may explain how anhedonia and depression can lead to weight gain.

Assessment of the Relationship between Non-motor features and Severity of Parkinson's Disease Patients in Bangladesh.

Parkinson's disease (PD) is second most common neurodegenerative disorder after Alzheimer's disease that may present with both motor and non-motor symptoms (NMSs). Many of the ignored NMSs may potentiate further deterioration of the patient's quality of life (QoL). But there is scarcity of data regarding NMSs of PD patients and their relationship with the disease severity in Bangladesh. This study was aimed to investigate the frequency of NMSs and assess their debatable impact on the severity of PD patients in Bangladesh. This cross-sectional type of observational study was conducted in neurology department of Dhaka Medical College Hospital, Bangladesh from January 2012 to June 2013 which recruited 60 eligible PD patients. The PD patients and disease severity was demonstrated by UK Parkinson's Disease Society Brain Bank criteria for idiopathic PD and the Hoehn and Yahr scale respectively. Whereas, NMSs were demonstrated by the self-structured questionnaire which had encountered 30 common symptoms of PD. The mean age of our study cohort was found 57.88±10.56 years with male female ration 2:1. According to the Hoehn and Yahr (H & Y) severity scale 38.3%, 38.3%, 20.1% and 3.3% patients had been suffering from stage ?, stage II, stage III and stage ?V Parkinson's disease respectively. Irrespective of the severity of the PD the frequency of NMSs was nocturia (66.7%), sadness or blues (65.0%), memory disturbance (61.7%), anxiety (58.3%), insomnia (56.7%), orthostatic hypotension (55.0%), erectile dysfunction (50.0%), urinary urgency (46.7%), anhedonia (45.0%), olfactory disturbance (38.3%), constipation (38.3%), hyper or hypo sexuality (31.7%) and restless leg syndrome (31.7%). However, after head-to-head NMSs analysis, daytime dribbling of saliva (p=0.024), urinary urgency (p=0.036), nocturia (p=0.001), weight loss (p=0.001), anhedonia (p=0.027), excessive daytime sleepiness (p=0.024), insomnia (p=0.007), vivid dream (p=0.024), REM behavior disorder (p=0.010), restless leg syndrome/ periodic leg movements (p=0.043) had significantly been reported higher among the stage II PD patients than that of stage I patients. Whereas fall (p=0.001), dysphagia or choking (p=0.002), constipation (p=0.003), fecal incontinence (p=0.033), excessive daytime sleepiness (p=0.033), anxiety (p=0.036) and anhedonia (p=0.044) were significantly more prevalent among the advanced stage (III) than stage (II) PD patients. Mean total NMS increased significantly with PD severity based on H and Y staging with a mean NMSQ-T (Non-Motor Symptoms Questionnaire Test) of 5.43 in stage 1, 9.22 in stage 2, 13.75 in stage 3 and 17.0 in stage 4 (p=0.0001). This study revealed that there was high frequency of NMSs among the PD patients and most common symptoms were nocturia, sadness, memory impairment, anxiety, insomnia, orthostatic hypotension, erectile dysfunction, anhedonia, urinary urgency and constipation. Finally, the more advanced disease as indicated by a higher H&Y stage was associated with significantly higher number of reported NMSs.

Multi-modal assessment of reward functioning in adolescent anhedonia.

BACKGROUND: Anhedonia is a core symptom of depression that predicts worse treatment outcomes. Dysfunction in neural reward circuits is thought to contribute to anhedonia. However, whether laboratory-based assessments of anhedonia and reward-related neural function translate to adolescents' subjective affective experiences in real-world contexts remains unclear. METHODS: We recruited a sample of adolescents (n = 82; ages 12-18; mean = 15.83) who varied in anhedonia and measured the relationships among clinician-rated and self-reported anhedonia, behaviorally assessed reward learning ability, neural response to monetary reward and loss (as assessed with functional magnetic resonance imaging), and repeated ecological momentary assessment (EMA) of positive affect (PA) and negative affect (NA) in daily life. RESULTS: Anhedonia was associated with lower mean PA and higher mean NA across the 5-day EMA period. Anhedonia was not related to impaired behavioral reward learning, but low PA was associated with reduced nucleus accumbens response during reward anticipation and reduced medial prefrontal cortex (mPFC) response during reward outcome. Greater mean NA was associated with increased mPFC response to loss outcome. CONCLUSIONS: Traditional laboratory-based measures of anhedonia were associated with lower subjective PA and higher subjective NA in youths' daily lives. Lower subjective PA and higher subjective NA were associated with decreased reward-related striatal functioning. Higher NA was also related to increased mPFC activity to loss. Collectively, these findings demonstrate that laboratory-based measures of anhedonia translate to real-world contexts and that subjective ratings of PA and NA may be associated with neural response to reward and loss.

Network analysis of depression in prostate cancer patients: Implications for assessment and treatment.

OBJECTIVES: Many prostate cancer patients also suffer from depression, which can decrease their life satisfaction and also impede recovery from their cancer. This study described the network structure of depressive symptomatology in prostate cancer patients, with a view to providing suggestions for clinical interventions for depressed patients. METHODS: Using a cross-sectional design, 555 prostate cancer patients completed the Patient Health Questionnaire-9 (PHQ-9). RESULTS: Network analysis and multidimensional scaling indicated that anhedonia was the most central symptom for these men, and that several sets of depression symptoms were closely associated with each other. These included anhedonia-depressed mood; sleeping problems-fatigue/lethargy; and suicidal ideation-low self-worth-depressed mood. Other depression symptoms such as appetite problems, concentration problems, and motor problems, were less well-related with the remainder of the network. Patients receiving treatment for reocurring prostate cancer (PCa) had significantly higher PHQ9 scores than patients undergoing their initial treatment, but no major differences in their network structures. Implications for clinical practice were derived from the relationships between individual depression symptoms and the overall depression network by examining node predictability. CONCLUSIONS: The use of total depression scores on an inventory does not reflect the underlying network structure of depression in PCa patients. Identification and treatment of the central symptom of anhedonia in PCa patients suggests the need to adopt specific therapies that are focussed upon this symptom.

The COVID-19 Pandemic and Mental Well-Being of Pregnant Women in Japan: Need for Economic and Social Policy Interventions.

OBJECTIVE: This study explores the mental well-being of pregnant women in Japan during the coronavirus disease (COVID-19) pandemic. METHODS: We collected 1777 responses from pregnant women through an online survey. Using the Japanese version of the Edinburgh Postnatal Depression Scale (EPDS), we calculated the percentage of pregnant women above the cutoff (≥ 13), and the factor scores of anhedonia, anxiety, and depression. Regression analyses were performed to identify factors and socioeconomic characteristics correlated with depressive symptoms. RESULTS: The point prevalence of pregnant women with an EPDS score of ≥ 13 was 17%. The mean scores were 0.73, 3.68, and 1.82 for anhedonia, anxiety, and depression, respectively. The probability of becoming above the cutoff score positively correlated with the cancellation of planned informal support, higher perceived risk for infection of COVID-19, difficulties in household finances, and lack of social support. Moreover, being younger, less wealthy, unemployed, and without a partner showed a significantly higher possibility of having a score above the cutoff. CONCLUSIONS: The present study found a high percentage of pregnant women with depressive symptoms. Notably, COVID-19-related variables, including perceived risk for the infection, fear of decreasing economic wealth, and social support, were significantly associated with depressive symptoms.

Assessment of Anhedonia in Adults With and Without Mental Illness: A Systematic Review and Meta-analysis.

Importance: Anhedonia, a reduced capacity for pleasure, is described for many psychiatric and neurologic conditions. However, a decade after the Research Domain Criteria launch, whether anhedonia severity differs between diagnoses is still unclear. Reference values for hedonic capacity in healthy humans are also needed. Objective: To generate and compare reference values for anhedonia levels in adults with and without mental illness. Data Sources: Web of Science, Scopus, PubMed, and Google Scholar were used to list all articles from January 1, 1995 to July 2, 2019, citing the scale development report of a widely used anhedonia questionnaire, the Snaith-Hamilton Pleasure Scale (SHAPS). Searches were conducted from April 5 to 11, 2018, and on July 2, 2019. Study Selection: Studies including healthy patients and those with a verified diagnosis, assessed at baseline or in a no-treatment condition with the complete 14-item SHAPS, were included in this preregistered meta-analysis. Data Extraction and Synthesis: Random-effects models were used to calculate mean SHAPS scores and 95% CIs separately for healthy participants and patients with current major depressive disorder (MDD), past/remitted MDD, bipolar disorder, schizophrenia, substance use disorders, Parkinson disease, and chronic pain. SHAPS scores were compared between groups using meta-regression, and traditional effect size meta-analyses were conducted to estimate differences in SHAPS scores between healthy and patient samples. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Main Outcomes and Measures: Self-reported anhedonia as measured by 2 different formats of the SHAPS (possible ranges, 0-14 and 14-56 points), with higher values on both scales indicating greater anhedonia symptoms. Results: In the available literature (168 articles; 16 494 participants; 8058 [49%] female participants; aged 13-72 years), patients with current MDD, schizophrenia, substance use disorder, Parkinson disease, and chronic pain scored higher on the SHAPS than healthy participants. Within the patient groups, those with current MDD scored considerably higher than all other groups. Patients with remitted MDD scored within the healthy range (g = 0.1). This pattern replicated across SHAPS scoring methods and was consistent across point estimate and effect size analyses. Conclusions and Relevance: The findings of this meta-analysis indicate that the severity of anhedonia may differ across disorders associated with anhedonia. Whereas anhedonia in MDD affects multiple pleasure domains, patients with other conditions may experience decreased enjoyment of only a minority of life's many rewards. These findings have implications for psychiatric taxonomy development, where dimensional approaches are gaining attention. Moreover, the SHAPS reference values presented herein may be useful for researchers and clinicians assessing the efficacy of anhedonia treatments.

Anhedonia following mild traumatic brain injury in rats: A behavioral economic analysis of positive and negative reinforcement.

Psychiatric disorders affect nearly 50% of individuals who have experienced a traumatic brain injury (TBI). Anhedonia is a major symptom of numerous psychiatric disorders and is a diagnostic criterion for depression. It has recently been appreciated that reinforcement may be separated into consummatory (hedonic), motivational and decisional components, all of which may be affected differently in disease. Although anhedonia is typically assessed using positive reinforcement, the importance of stress in psychopathology suggests the study of negative reinforcement (removal or avoidance of aversive events) may be equally important. The present study investigated positive and negative reinforcement following a rat model of mild TBI (mTBI) using lateral fluid percussion. Hedonic value and motivation for reinforcement was determined by behavioral economic analyses. Following mTBI, the hedonic value of avoiding foot shock was reduced. In contrast, the hedonic value of escaping foot shock or obtaining a sucrose pellet was not altered by mTBI. Moreover, motivation to avoid or escape foot shock or to acquire sucrose was not altered by mTBI. Our results suggest that individuals experiencing mTBI find avoidance of aversive events less reinforcing, and therefore are less apt to utilize proactive control of stress.

Self-assessment of negative symptoms - Critical appraisal of the motivation and pleasure - Self-report's (MAP-SR) validity and reliability.

OBJECTIVE: The negative symptom domain remains a major challenge concerning treatment. A valid self-report measure could assist clinicians and researchers in identifying patients with a relevant subjective burden. The Motivation and Pleasure - Self Report (MAP-SR) derives from the CAINS and is supposed to reflect the "amotivation" factor of negative symptoms. We evaluated different aspects of the scale's reliability and validity. This is the first factorial analysis as well as the first analysis of test-retest reliability. METHODS: We assessed three samples of subjects with schizophrenia or schizoaffective disorder (n = 93) and a broad spectrum of related domains. RESULTS: We explored a 3-, 2- and 1-factor solution (explaining 50.93, 44.85 and 36.18% of variance, respectively). The factor "pleasure and hedonic activity" consists of eight items and was most robust; the factors "social motivation" and "motivation for work" were problematic. Test-retest reliability of the scale was adequate (rS = 0.63, p = .005). Neither the MAP-SR nor the "pleasure and hedonic activities" factor are associated with the PANSS negative symptom scale. There are significant associations with the observer-rated CAINS-MAP scale, experiences of pleasure, and social cognition but none with functional outcome. Discriminant validity could not be established with regards to depression and extrapyramidal symptoms. CONCLUSIONS: We found that the MAP-SR is adequate to assess anhedonia but is less suitable when assessing motivation. Therefore, we propose using the "pleasure and hedonic activity scale" to cover the "anhedonia" subdomain. We think the "motivation" part of the instrument requires reconstruction.

The cognitive effort expenditure for rewards task (C-EEfRT): A novel measure of willingness to expend cognitive effort.

Research in animals suggests that decisions about physical versus cognitive effort have distinct neural bases, but exploration of this question in humans is hampered by lack of parallel measures of physical and cognitive effort for rewards. We developed a novel measure of willingness to exert cognitive effort for rewards, the C-EEfRT, paralleling the validated physical effort expenditure for rewards task (EEfRT). To validate the C-EEfRT we: (a) tested whether EEfRT and C-EEfRT tasks were equivalently difficult; (b) tested whether decisions on the EEfRT and C-EEfRT were equivalently responsive to changes in reward; (c) examined relationships between the C-EEfRT and anhedonia, intelligence, and working memory. Last, we tested the relationship between willingness to exert physical and cognitive effort for rewards in humans. Sixty healthy adults completed the EEfRT, the C-EEfRT, an anhedonia self-report, an intelligence test, and a working memory task. Overall willingness to exert effort was higher on the C-EEfRT than the EEfRT, particularly when reward probability and amount were low. This was despite participants perceiving the cognitive task as more difficult, and having greater difficulty completing it. Differential effects of physical fatigue may have contributed. Anhedonia was not related to effort on either measure. Working memory, but not intelligence, was associated with cognitive effort. There was a moderate relationship between cognitive and physical effort. These findings suggest the importance of measuring cognitive effort as distinct from physical effort in humans. Future studies should consider calibrating task difficulty for each individual, and exploring cognitive effort in clinical populations. (PsycINFO Database Record

Assessment of depression-like behavior and anhedonia after repeated cycles of binge-like ethanol drinking in male C57BL/6J mice.

Psychological depression is frequently linked to alcohol abuse and even serves as key indicators of an alcohol use disorder (AUD). This relationship is supported by preclinical findings in which depression-like phenotypes develop in animals exposed to chronic intermittent ethanol vapor, a common preclinical model of alcohol dependence. However, the emergence of these maladaptive phenotypes following repeated binge-like ethanol drinking remains relatively unexplored. The purpose of this study was to evaluate depression-like behaviors associated with binge-like consumption in mice. Using the drinking-in-the-dark (DID) paradigm, we examined the impact of multiple binge-like cycles (1, 3, or 6) on depression-like behaviors in the forced swim test (FST) and sucrose preference as a test for anhedonia. We also assessed the effect of repeated binge cycles on the consumption of bitter and sweet tastants over a range of concentrations. Results indicated that binge-like ethanol drinking did not lead to depression-like behavior as repeated cycles of DID did not alter sucrose consumption or preference nor did it impact time spent immobile during the FST. Animals that experienced six cycles of DID showed increased quinine consumption and increased quinine preference, which may be indicative of an escalated preference for tastants that resemble the gustatory aspects of ethanol. Interestingly, an unexpected ~20% increase in hypermobility was observed after three cycles of binge-like ethanol drinking. Although the FST is most frequently used to model depression-like behavior, emerging evidence suggests that increased hypermobility during the FST could be indicative of an inability to cope in a stressful situation, suggesting that repeated ethanol exposure in the present experiment transiently enhances stress reactivity.

Cross Cultural Validation and Extension of the Clinical Assessment Interview for Negative Symptoms (CAINS) in the Chinese Context: Evidence from a Spectrum Perspective.

The Clinical Assessment Interview for Negative Symptoms (CAINS) was designed in accordance with the recent theory and research in social affective neuroscience and to address the psychometric and conceptual limitations of other instruments assessing negative symptoms. The present study aimed to provide a large-scale validation of the CAINS in China and examine its applicability and validity evidence across the schizophrenia spectrum. Using confirmatory factor analysis, our results replicated the original findings in the US development samples that the CAINS possesses a stable 2-factor structure, namely "motivation/pleasure" and "expression". We also found significant correlations between the CAINS and other negative symptom measures. The CAINS demonstrated good discriminant validity in differentiating negative symptoms in people with schizophrenia, nonpsychotic first-degree relatives and people with social anhedonia. People with schizophrenia exhibited significantly higher CAINS subscale scores than first-degree relatives and healthy controls. In addition, first-degree relatives had higher "motivation/pleasure" scores than healthy controls. The "motivation/pleasure" subscale scores of individuals with social anhedonia were also significantly higher than healthy controls.

Assessment of Snaith-Hamilton Pleasure Scale (SHAPS): the dimension of anhedonia in Italian healthy sample.

The Snaith-Hamilton Pleasure Scale (SHAPS) is a rapid screening battery created for assessing the presence of anhedonia, namely the inability to experience pleasure. Although, this symptom has widely been investigated in clinical settings, individual differences in anhedonia are also present in healthy population. The aim of present study was to validate the translated Italian version of this test. One thousand six hundred ninety-seven consecutive healthy subjects (55% female) of different ages (age 18-82 years) underwent SHAPS. Participants who showed mild level of anhedonia also completed the Apathy Evaluation Scale (AES), Beck Depression Inventory (BDI), Toronto Alexithymia Scale-20 (TAS), Mood Disorders Insight Scale (MDIS), and Beck Hopelessness Scale (BHS). The SHAPS showed good internal consistency and discriminant validity; moreover, the factorial analysis highlighted that SHAPS had a three-factor structure for explaining the anhedonic construct. 14.9% showed a significant reduction of hedonic tone (SHAPS ≥ 3). Finally, the degree of anhedonia was significantly correlated with BDI and BHS scores, but not with age or gender. Although anhedonia is a prominent feature of many psychiatric and neurological disorders, the presence of this symptom in the healthy population highlighted the importance to develop reliable tool. SHAPS shows good psychometric properties to assess multidimensional anhedonia symptoms also in Italian healthy population.

Assessment of nicotine withdrawal-induced changes in sucrose preference in mice.

Anhedonia, induced by nicotine withdrawal, may serve as an important affective sign that reinforces tobacco use and smoking relapse rates in humans. Animal models provide a way to investigate the underlying neurobiological factors involved in the decrease in responding for positive affective stimuli during nicotine withdrawal and may aid in drug development for nicotine dependence. Thus, we explored the use of the sucrose preference test to measure nicotine withdrawal-induced reduction in response for positive affective stimuli in mice. C57BL/6J and knockout (KO) mice were chronically exposed to different doses of nicotine through surgically implanted subcutaneous osmotic minipumps for 14days and underwent spontaneous nicotine withdrawal on day 15. A sucrose preference time course was performed and the results were compared to another well-established affective sign of nicotine withdrawal, the reduction in time spent in light side, using the Light Dark Box test. Subsequently, our results demonstrated a time-dependent and dose-related reduction in sucrose preference in nicotine withdrawn male C57BL/6J mice, indicative of a decrease in responding for positive affective stimuli. Furthermore, the sucrose preference reduction during nicotine withdrawal was consistent with decrease in time spent in the light side of the Light Dark Box test. We also found the reduction for positive affective stimuli and time spent in the light side was not present in nicotine withdrawn ß2 and α6 KO mice, suggesting that these nicotinic subunits are involved in the affective signs of nicotine withdrawal. Thus, this report highlights the potential utility of the sucrose preference test as a useful measure of the decrease in responding for positive affective stimuli during spontaneous nicotine withdrawal.

The indirect assessment of social anhedonia in Chinese adolescents: Preliminary findings.

Nearly all self-report measures of anhedonia have been developed for use in adults. Recently we developed an age and developmentally appropriate measure of social/interpersonal pleasure for adolescents (ACIPS-A), whereby lower scores are indicative of social anhedonia. However the scale had not been administered to Eastern samples. The adolescent version of the Anticipatory and Consummatory Interpersonal Pleasure Scale (ACIPS-A) was administered to a general, community-derived Chinese adolescent sample of 442 students, including 186 males (44%), who ranged in age from 12 to 18 years old. The 20-item Chinese Temporal Experience of Pleasure (TEPS) was also administered to the sample. Exploratory factor analysis revealed that three factors (Casual bonding, Close relationships, and Shared interests) accounted for nearly 69% of the variance. The total ACIPS-A showed excellent internal consistency, with ordinal alpha = 0.94. Scores on the adolescent version of the ACIPS were positively and significantly associated with total scores on the four Chinese TEPS subscales. The ACIPS-A is a sufficiently robust measure to be useful and valid in Chinese samples as well as in Western (i.e. European and U.S.) samples.

Distinct Subtypes of Apathy Revealed by the Apathy Motivation Index.

Apathy is a debilitating but poorly understood disorder characterized by a reduction in motivation. As well as being associated with several brain disorders, apathy is also prevalent in varying degrees in healthy people. Whilst many tools have been developed to assess levels of apathy in clinical disorders, surprisingly there are no measures of apathy suitable for healthy people. Moreover, although apathy is commonly comorbid with symptoms of depression, anhedonia and fatigue, how and why these symptoms are associated is unclear. Here we developed the Apathy-Motivation Index (AMI), a brief self-report index of apathy and motivation. Using exploratory factor analysis (in a sample of 505 people), and then confirmatory analysis (in a different set of 479 individuals), we identified subtypes of apathy in behavioural, social and emotional domains. Latent profile analyses showed four different profiles of apathy that were associated with varying levels of depression, anhedonia and fatigue. The AMI is a novel and reliable measure of individual differences in apathy and might provide a useful means of probing different mechanisms underlying sub-clinical lack of motivation in otherwise healthy individuals. Moreover, associations between apathy and comorbid states may be reflective of problems in different emotional, social and behavioural domains.

Individual negative symptoms and domains - Relevance for assessment, pathomechanisms and treatment.

The negative symptoms of schizophrenia can be divided into two domains. Avolition/apathy includes the individual symptoms of avolition, asociality and anhedonia. Diminished expression includes blunted affect and alogia. Until now, causes and treatment of negative symptoms have remained a major challenge, which is partially related to the focus on negative symptoms as a broad entity. Here, we propose that negative symptoms may become more tractable when the different domains and individual symptoms are taken into account. There is now increasing evidence that the relationship with clinical variables - in particular outcome - differs between the domains of avolition/apathy and diminished expression. Regarding models of negative symptom formation, those relevant to avolition/apathy are now converging on processes underlying goal-directed behavior and dysfunctions of the reward system. In contrast, models of the diminished expression domains are only beginning to emerge. The aim of this article is to review the specific clinical, behavioral and neural correlates of individual symptoms and domains as a better understanding of these areas may facilitate specific treatment approaches.

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

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.