Association Between Symptom Dimensions and Categorical Diagnoses of Psychosis: A Cross-sectional and Longitudinal Investigation

TY - JOUR

T1 - Association Between Symptom Dimensions and Categorical Diagnoses of Psychosis

T2 - A Cross-sectional and Longitudinal Investigation

AU - Russo, Manuela

AU - Levine, Stephen Z.

AU - Demjaha, Arsime

AU - Di Forti, Marta

AU - Bonaccorso, Stefania

AU - Fearon, Paul

AU - Dazzan, Paola

AU - Pariante, Carmine M.

AU - David, Anthony S.

AU - Morgan, Craig

AU - Murray, Robin M.

AU - Reichenberg, Abraham

PY - 2014/1

Y1 - 2014/1

N2 - Context: Cross-sectional studies of the signs and symptoms of psychosis yield dimensional phenotypes. However, the validity and clinical utility of such dimensions remain debated. This study investigated the structure of psychotic symptomatology, the stability of the structure over time, and the concordance between symptom dimensions and categorical diagnoses.  Methods: Sample consisted of 500 first-episode psychotic patients. A cross-sectional study (N = 500) investigated the organizational structure of symptom dimensions at the onset of psychosis and its concordance with categorical diagnoses; next, a nested longitudinal study (N = 100) examined the stability of the symptom dimensions structure after 5-10 years of follow-up.  Results: Factor analyses identified 6 first-order factors (mania, negative, disorganization, depression, hallucinations, and delusions) and 2 high-order factors (affective and nonaffective psychoses). Cumulative variance accounted for by the first and high-order factors was 63%: 31% by the first-order factors and 32% by the high-order factors. The factorial structure of psychotic symptoms during first episode remained stable after 5-10 years of follow- up. The overall concordance between 4 categorical diagnostic groups (schizophrenia, mania with psychosis, psychotic depression and schizoaffective disorder) and dimensional symptom ranged from 62.2% to 73.1% (when the schizoaffective group was excluded).  Conclusions: Symptoms of psychosis assume a multidimensional hierarchical structure. This hierarchical model was stable over time and showed good concordance with categorical diagnoses. The combined use of dimensional and categorical approach to psychotic disorders would be of clinical and research utility.

AB - Context: Cross-sectional studies of the signs and symptoms of psychosis yield dimensional phenotypes. However, the validity and clinical utility of such dimensions remain debated. This study investigated the structure of psychotic symptomatology, the stability of the structure over time, and the concordance between symptom dimensions and categorical diagnoses.  Methods: Sample consisted of 500 first-episode psychotic patients. A cross-sectional study (N = 500) investigated the organizational structure of symptom dimensions at the onset of psychosis and its concordance with categorical diagnoses; next, a nested longitudinal study (N = 100) examined the stability of the symptom dimensions structure after 5-10 years of follow-up.  Results: Factor analyses identified 6 first-order factors (mania, negative, disorganization, depression, hallucinations, and delusions) and 2 high-order factors (affective and nonaffective psychoses). Cumulative variance accounted for by the first and high-order factors was 63%: 31% by the first-order factors and 32% by the high-order factors. The factorial structure of psychotic symptoms during first episode remained stable after 5-10 years of follow- up. The overall concordance between 4 categorical diagnostic groups (schizophrenia, mania with psychosis, psychotic depression and schizoaffective disorder) and dimensional symptom ranged from 62.2% to 73.1% (when the schizoaffective group was excluded).  Conclusions: Symptoms of psychosis assume a multidimensional hierarchical structure. This hierarchical model was stable over time and showed good concordance with categorical diagnoses. The combined use of dimensional and categorical approach to psychotic disorders would be of clinical and research utility.

KW - symptom dimensions

KW - diagnostic classification

KW - psychosis

KW - DSM 5

KW - longitudinal study

KW - NEGATIVE SYNDROME SCALE

KW - SEVERE MOOD DISORDERS

KW - BIPOLAR DISORDER

KW - DSM-V

KW - SCHIZOPHRENIA

KW - HETEROGENEITY

KW - DICHOTOMY

KW - THERAPY

KW - THOUGHT

KW - MANIA

U2 - 10.1093/schbul/sbt055

DO - 10.1093/schbul/sbt055

M3 - Article

SN - 0586-7614

VL - 40

SP - 111

EP - 119

JO - Schizophrenia Bulletin

JF - Schizophrenia Bulletin

IS - 1

ER -