Last reviewed: 28 Sep 2021
Last updated: 03 Nov 2020



History and exam

Key diagnostic factors

  • presence of risk factors
  • sad and/or irritable mood
  • decreased interest or lack of enjoyment
  • significant functional impairment
  • no evidence of a manic or hypomanic episode
  • no history of recent bereavement

Other diagnostic factors

  • decreased concentration or indecision
  • insomnia or hypersomnia
  • change of appetite or weight
  • excessive fatigue
  • feelings of worthlessness or excessive guilt
  • feelings of hopelessness
  • psychomotor agitation or retardation
  • somatic complaints
  • social withdrawal or change of friends
  • recurrent thoughts of death or suicidal ideation
  • increased substance use

Risk factors

  • positive family history of depression
  • other parental psychopathology
  • personal history of other psychiatric disorders (e.g., anxiety)
  • stress or trauma
  • female sex
  • sexual minority status
  • personal history of chronic medical illness
  • postnatal status
  • neighbourhood and social instability
  • immunosuppressive medications (e.g., corticosteroids, interferon)
  • substance use/abuse

Diagnostic investigations

Investigations to consider

  • serum thyroid-stimulating hormone (TSH) and free thyroxine (T4)
  • full blood count with differential
  • urine drug screen
  • urine pregnancy test
  • serum B12 and folate
  • vitamin D level

Treatment algorithm



Lisa Pan, MD

Assistant Professor of Psychiatry and Clinical and Translational Science

University of Pittsburgh

Attending Physician

Services for Teens at Risk




LP declares that she has no competing interests.

David A. Brent, MD

Endowed Chair in Suicide Studies

Professor of Psychiatry, Pediatrics, Epidemiology, and Clinical and Translational Science

University of Pittsburgh



DAB receives royalties from Guilford Press; has received or will receive royalties from the electronic self-rated version of the C-SSRS from ERT, Inc; is on the editorial board of UpToDate; is a reviewer for Healthwise; and is on the board of the Klingenstein Foundation.


Dr Lisa Pan and Dr David A. Brent would like to gratefully acknowledge Dr Rongrong Tao, Dr Graham Emslie, and Dr Taryn Mayes, the previous contributors to this topic. RT is an author of a number of references cited in this topic. GE has received research funds from BioMarin, Eli Lilly, Forest Laboratories, GlaxoSmithKline, and Somerset; has served as a consultant for Biobehavioral Diagnostic Company, Bristol-Myers Squibb, Eli Lilly, Forest Laboratories, GlaxoSmithKline, INC Research Inc., Lundbeck, Pfizer Inc., Seaside Therapeutics, Shire Pharmaceuticals, Valeant, Validus Pharmaceuticals, and Wyeth Ayerst; and has been on the speaker's bureau for Forest Laboratories. TM is an author of a number of references cited in this topic.

Peer reviewers

Paramala J. Santosh, MBBS, DipNB (Psych), MRCPsych, MD

Honorary Senior Lecturer

Institute of Child Health and Institute of Psychiatry

Consultant in Child and Adolescent Neuropsychiatry and Psychopharmacology

Head of Centre for Interventional Paediatric Psychopharmacology

Department of Child & Adolescent Mental Health

Great Ormond Street Hospital for Children




PJS declares that he has no competing interests.

Pieter Joost van Wattum, MD, MA

Assistant Clinical Professor of Child Psychiatry

Yale School of Medicine

Medical Director of Psychiatry

Clifford W. Beers Guidance Clinic

New Haven



PJvW declares that he has no competing interests.

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