title: A prospective longitudinal 10-year study of schizophrenia's three major factors and depression.
abstract: This study investigated the nature, independence, and stability of schizophrenia's syndrome factors and depression at 2, 4.5, 7.5 and 10 years post-index hospitalization. At the four follow-ups, 71 patients (48 with schizophrenia and 23 with schizoaffective disorder) were assessed for symptoms hypothesized to constitute the reality distortion, disorganized, and negative factors of schizophrenia. At the last three follow-ups, the patients were also assessed for symptoms of depression. Factor analyses of schizophrenia symptoms revealed more than three syndrome factors at each follow-up. Longitudinally, reality distortion was a stable and relatively independent factor. The negative syndrome was independent but was bifurcated into two dimensions, interpreted as social/emotional withdrawal and diminished movement/expressiveness. Although signs of disorganization were not unified or independent early in schizophrenia's course, speech/thought disorder, disorganized affect, and poverty of speech content coalesced to form a disorganization factor by the 7.5-year follow-up. When depressive symptoms were added to the analyses, depression constituted an independent and stable dimension of schizophrenia over time. Each schizophrenia factor demonstrated a unique longitudinal course. Courses included stable symptom consistency (reality distortion), evolving symptom convergence (disorganization), and recurrent bifurcation and symptom instability (the negative syndrome).
authors: Northwestern University, Department of Psychiatry and Behavioral Sciences, Superior and Fairbanks Court, Chicago, IL 60611, USA. j-marengo@northwestern.edue
authors: J
authors: J
authors: Marengo
authors: M
authors: M
authors: Harrow
authors: E S
authors: ES
authors: Herbener
authors: J
authors: J
authors: Sands
mesh_terms: D000328:Adult; D002908:Chronic Disease; D015986:Confounding Factors, Epidemiologic; D003863:Depression / Q000175:diagnosis / Q000209:etiology* / Q000523:psychology*; D018450:Disease Progression; D005163:Factor Analysis, Statistical; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000150:complications* / Q000188:drug therapy; D012565:Schizophrenic Psychology; D012720:Severity of Illness Index; D013997:Time Factors