title: Baseline putamen volume as a predictor of positive symptom reduction in patients at clinical high risk for psychosis: A preliminary study.
abstract: OBJECTIVE
  Illness course in individuals at clinical high risk (CHR) status for psychosis is heterogeneous, which limits effective treatment for all CHR subgroups. Baseline predictors of positive symptom trajectory in the CHR group will reduce such limitations. We singled out the putamen, thought to be involved in the generation of the key schizophrenia symptoms early in the course of disease, as a potential predictor of positive symptom trajectory in CHR patients.
  
  
  METHODS
  We recruited 45 CHR patients and 29 age- and gender-matched healthy controls (HC). The CHR group was divided into patients with positive symptom reduction (CHR-R) and patients without positive symptom reduction (CHR-NR) at 6 months. Comparisons were made between the baseline putamen volumes of CHR-R, CHR-NR and HC groups. The relationship between baseline putamen volumes and clinical measures was investigated.
  
  
  RESULTS
  Left putamen volumes of CHR-R patients were significantly smaller than those of HCs (p=0.002) and of CHR-NR patients (p=0.024). CHR-R patients had significantly reduced leftward laterality compared to HCs (p=0.007). In the CHR-R group, bilateral putamen volumes were correlated with positive symptom severity at baseline (r=-0.552, p=0.001) and at 6 months (r=-0.360, p=0.043), and predicted positive symptom score change in 6 months at a trend level (p=0.092).
  
  
  CONCLUSIONS
  Smaller left putamen volumes in CHR-R patients, and the correlation between positive symptom severity and putamen volumes suggest that putamen volume is a possible risk-stratifier and predictor of clinical course in the CHR population.
authors.affiliation: Department of Psychiatry, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Sang Bin
authors.initials: SB
authors.lastname: Hong
authors.affiliation: Department of Psychiatry, Seoul National University College of Medicine, Seoul, Republic of Korea; Medical Research Center, Seoul National University College of Medicine, Seoul, Republic of Korea. Electronic address: leetaey@snu.ac.kr.
authors.forename: Tae Young
authors.initials: TY
authors.lastname: Lee
authors.affiliation: Department of Brain & Cognitive Sciences, Seoul National University College of National Sciences, Seoul, Republic of Korea.
authors.forename: Yoo Bin
authors.initials: YB
authors.lastname: Kwak
authors.affiliation: Department of Psychiatry, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Sung Nyun
authors.initials: SN
authors.lastname: Kim
authors.affiliation: Department of Psychiatry, Seoul National University College of Medicine, Seoul, Republic of Korea; Medical Research Center, Seoul National University College of Medicine, Seoul, Republic of Korea; Department of Brain & Cognitive Sciences, Seoul National University College of National Sciences, Seoul, Republic of Korea.
authors.forename: Jun Soo
authors.initials: JS
authors.lastname: Kwon
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D016022:Case-Control Studies; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D017063:Outcome Assessment, Health Care; D062706:Prodromal Symptoms; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000473:pathology*; D011699:Putamen / Q000473:pathology*; D012307:Risk Factors; D055815:Young Adult
keywords: Clinical high risk; Positive symptom; Predictors; Psychosis; Putamen