Counting the OCD suffers

Hvor mange lider af OCD? Tja, det afhænger af hvilket diagnosesystem man benytter. Indtil 1970’erne antog man at det drejede sig om et beskedent antal personer. Så udførte man en række epidemiologiske undersøgelser bl.a. i USA, hvor man kom frem til at det nok var et sted mellem 2% til 3%, hvilket blev bekræftet af andre studier rundt om i verden. En australsk undersøgelse, der publiceres i det seneste nummer af American Journal of Psychitry, er kommet frem til at det ‘kun’ drejer sig om 0,6% af en population, hvis man følger DSM-IV kriterierne for at få diagnosen OCD. De tidligere undersøgelser blev udført efter DSM-III kriterierne for at få diagnosen OCD.
Det rejser spørgsmålet: hvornår har man OCD (og andre psykiatriske lidelser)? Er det når man har fået stillet diagnosen efter DSM-III, DSM-IV, DSM-IV TR eller ICD 9 eller 10 ? (ICD-10 er WHOs diagnosesystem og benyttes bl.a. i Danmark).
DSM-IV TR er en revideret version af DSM-IV og man kan selvfølgelig spørge om hvorfor de australske forskere ikke har anvendt denne? Forskerne har åbnet en interessant diskussion om diagnostik af OCD og man kan kun håbe at der opnås en konsensus i fagkredse om at stille den korrekte diagnose.
Der skal dog lige tilføjes at opfatte OCD (og sikkert andre psykiske lidelser) som konstant i en befolkning er misvisende, fordi årsagerne til OCD er mange, bl.a. ser man efter store influenzaepidemier (såkalte pandemier) en øget forekomst af OCD.

Counting the Counters
The rates of obsessive-compulsive disorder (OCD) in several epidemiological studies have been surprisingly high, up to 2.5% of the general population. Broad diagnostic criteria and lay interviewers may have led to overcounting. Many people have intrusive thoughts and ritualized behaviors, but generally these do not interfere with our lives. Crino et al. (p. 876) report an Australian survey of 10,641 adults that included only obsessions or compulsions causing marked distress, consuming substantial time, and interfering with functioning. By these standards, OCD was present in 0.6% of the population. OCD was often accompanied by other psychiatric disorders, but substance abuse was less common than in other surveys. Compared to earlier diagnostic systems, the current criteria were more likely to identify people who are disabled, receive medical services, and are unemployed. This suggests a more accurate identification of people with true illness.

Source: American Journal of Psychitry 162:A64, May 2005, In This Issue: Counting the Counters


Abstract:

The Changing Prevalence and Severity of Obsessive-Compulsive Disorder Criteria From DSM-III to DSM-IV
Rocco Crino, Ph.D., Tim Slade, Ph.D., and Gavin Andrews, M.D.

OBJECTIVE: Relative to other mental disorders, the prevalence of obsessive-compulsive disorder (OCD) in the general population is not well established. Some epidemiological surveys have determined the prevalence of DSM-III OCD, but this is one of the first reports, to the authors’ knowledge, of DSM-IV OCD’s prevalence. METHOD: Data from the Australian National Survey of Mental Health and Well-Being, a nationally representative epidemiological survey of mental disorders, were analyzed. The prevalence and associated characteristics of DSM-IV OCD were identified, and then the data were rescored for DSM-III OCD. Cases defined by each system were compared. RESULTS: The 12-month prevalence of DSM-IV OCD was 0.6%, considerably less than found in surveys employing DSM-III diagnostic criteria. DSM-IV OCD showed significantly higher levels of comorbidity, disability, health service use, and treatment received. CONCLUSIONS: Changes in the reported prevalence and severity of OCD between DSM-III and DSM-IV cases are most likely a function of the differences in diagnostic criteria between DSM-III and DSM-IV.

Source: American Journal of Psychitry 162:876-882, May 2005,
The Changing Prevalence and Severity of Obsessive-Compulsive Disorder Criteria From DSM-III to DSM-IV
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