Diagnostic criteria

The diagnosis of OCD can be made according two main international classification systems, ICD-10 and DSM-V.

ICD-10 diagnostic criteria (under the category of “neurotic, stress-related and somatoform disorders”)

• For a definite diagnosis, obsessional symptoms or compulsive acts, or both, must be present on most days for at least 2 successive weeks and be a source of distress or interference with activities.The obsessional symptoms should have the following characteristics:
  • (a)they must be recognized as the individual's own thoughts or impulses;
  • (b)there must be at least one thought or act that is still resisted unsuccessfully, even though others may be present which the sufferer no longer resists;
  • (c)the thought of carrying out the act must not in itself be pleasurable (simple relief of tension or anxiety is not regarded as pleasure in this sense);
  • (d)the thoughts, images, or impulses must be unpleasantly repetitive.

DSM-V diagnostic criteria (under the category “obsessive-compulsive and related disorders”)

• presence of either obsessions, compulsions, or both
  • obsessions are defined by the following:
    • recurrent and persistent thoughts, urges, or images that are experienced as intrusive and unwanted and that cause marked anxiety or distress
    • the individual attempts to ignore or suppress such thoughts, urges, or images, or to neutralize them with other thoughts or actions
  • compulsions are defined by the following:
    • repetitive behaviors (e.g., hand washing, ordering, checking) or mental acts (e.g., praying, counting, repeating words silently) that the individual feels driven to perform in response to an obsession or according to rigid rules
    • compulsions are aimed preventing or reducing anxiety or preventing some dreaded situation or event; however, they are not connected in a realistic way with what they are designed to neutralize or are clearly excessive
• the obsessions or compulsions are time-consuming (e.g., take >1h/day) or cause clinically significant distress or functional impairment
• specify patient’s degree of insight as to reality of OCD beliefs:
  • good or fair insight (i.e., definitely or probably not true)
  • poor insight (i.e., probably true)
  • absent insight (i.e., completely convinced beliefs are true)
• specify if “tic-related” OCD

Reference:

• (1) World Health Organization (WHO). The ICD-10 Classification of Mental and Behavioural Disorders
• (2) Katzman MA et al. Canadian clinical practice guidelines for the management of anxiety, posttraumatic stress and obsessive-compulsive disorders. BMC Psychiatry. 2014;14 Suppl 1:S1.