Obsessive-Compulsive Disorder: Towards Better Understanding and Outcomes

Kenneth C. Kirkby


Curr Opin Psychiatry. 2003;16(1) 

In This Article

Comorbidity and Comparisons With Other Disorders

OCD occupies an interesting diagnostic niche in Venn diagrams, with overlaps including those with anxiety and mood disorders, eating disorders, impulse control problems, psychosis and a range of organic conditions. This is an area of considerable interest to clinicians faced with a variety of presentations and family histories. The overall rate of comorbidity is reported as two thirds of OCD patients, the preponderance being anxiety and depressive diagnoses.[25*] Interestingly, subclinical OCD presentations are reported to be less associated with comorbidity.[26*]

In anorexia nervosa the intense and preoccupying thoughts and behaviours bear some resemblance to OCD, as reviewed by Yaryura-Obias,[27*] though investigations to date implicate more an obsessive-compulsive personality disorder as the thematic link, as Serpell[28*] elucidates.

The continuum of impairment of insight in OCD and the more bizarre obsessional ideas sometimes seen as well as the occurrence of obsessions and compulsions in classical psychotic disorders, such as schizophrenia, and the indications for antipsychotics, are of enduring interest, as illustrated in a case series by Ganesan.[29*]

From the French literature comes a fresh look at the overlap of the bipolar spectrum, especially bipolar II and cyclothymia, with OCD[30**,31*] Comorbidity rates for hypomania and cyclothymia, over 30 and 40% respectively in members of an OCD consumer association, are mirrored in a subsequent study on psychiatric patients with OCD. An example of the shifting sands of diagnostic categories, these intriguing findings warrant further investigation in other samples.

Other studies examine a broad range: autistic traits analogous to those seen in high functioning autism and Asperger's syndrome are reported in 19% of an OCD sample;[32*] the risk seeking, reward-dependent personality traits in pathological gambling do not match traits in OCD,[33*] though it is difficult to disambiguate premorbid from state factors in addiction research. Attention deficit hyperactivity disorder and OCD seem independent;[34*] inherited myoclonus-dystonia appears associated with OCD in families with linkage to 7q21,[35**] joining Tourette's syndrome[36*] and tic disorders[37**] as a test bed for the association between neurological conditions and OCD.

The influence of OCD comorbidity on the course of other disorders is addressed for panic disorder, where comorbid OCD is associated with younger age of onset of panic attacks[38*] though the two disorders are very different in other respects such as rate of panic-induced hyperventilation.[39*] When post-traumatic stress disorder is present outcome of behaviour treatment of poorly responsive OCD is reported to be reduced.[40*]

Rounding off this interesting range of studies on comorbidity, in a more cultural and indeed spiritual dimension, is an investigation of the relationship between religious obsessions and OCD. This confirms that religious obsessions are common, more so when the variety of obsessions experienced is greater, but are not related to severity of other OCD symptoms,[41*] suggesting that religious obsessions are an embellishment of the disorder rather than a determinant.


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