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Last reviewed: 16 Mar 2025
Last updated: 27 Jul 2022

Summary

Definition

History and exam

Key diagnostic factors

  • positive symptoms
  • negative symptoms
  • disorder of perception
  • delusions
  • disturbances in emotions
  • incongruent affect
  • disorders of stream and form of thought
  • cognitive abnormalities
  • deficit symptoms
  • major depressive episodes
  • manic episodes

Other diagnostic factors

  • neurological deficit
  • family history
  • functional impairment
  • disorders of behaviour

Risk factors

  • family history of schizophrenia
  • substance use
  • age of the father at patient's birth
  • psychological stress
  • environment

Diagnostic investigations

1st investigations to order

  • urine drug screen
  • sexually transmitted disease screening
  • full blood count
  • thyroid function tests

Investigations to consider

  • laboratory studies to exclude organic causes
  • CT/MRI head
  • electroencephalogram (EEG)

Treatment algorithm

Contributors

Authors

Adrian Preda, MD
Adrian Preda

Professor of Clinical Psychiatry

Department of Psychiatry and Human Behavior

University of California, Irvine School of Medicine

Irvine

CA

Disclosures

AP was paid for consultancy work for GLG and Guidepoint.

Robert G. Bota, MD
Robert G. Bota

Associate Clinical Professor of Psychiatry

University of California

Irvine

CA

Disclosures

RGB declares that he has no competing interests.

Acknowledgements

Dr Adrian Preda and Dr Robert G. Bota would like to gratefully acknowledge Dr Bao-Nhan Benjamin Nguyen, who contributed to the updating of this topic.

Disclosures

BN declares that he has no competing interests.

Peer reviewers

Kemal Sagduyu, MD

Professor of Psychiatry

University of Missouri Kansas City

Kansas City

MO

Disclosures

KS declares that he has no competing interests.

William T. Regenold, MDCM

Associate Professor of Psychiatry

University of Maryland School of Medicine

Baltimore

MD

Disclosures

WTR declares that he has no competing interests.

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