Patients with anxiety disorder often have features of other disorder, specially the disturbances of mood found in depression. For example, diagnosis of Axis II personality disorder often accompanies an Axis I diagnosis of anxiety disorder. This is not surprising since problem diagnosed on Axis I often emerge from personality vulnerabilities. This diagnostic overlaps reflect comorbidity. The pic attached shows wide range of comorbidity, the co-occurrace of clinical symptoms, among various types of maladaptive behavior.
The table indicates that 77% of cases of paranoid disorders & schizophrenia in the population studied had only that diagnosis, whereas 23% of these cases had multiple diagnosis. Comorbidity estimates vary from study to study for several reasons, including the methods employed in making diagnoses & characteristics of samples surveyed. For example, 30% of cases of anxiety disorder involved multiple diagnoses, other studies using different population & diagnostic methods have found greater comorbidity for anxiety & depression disorders. One study found that though the risk of suicide in people with panic disorder is high, the risk is even higher in panic disorder cases that involved comorbidity with other disorders.
Comorbidity can occur within a given diagnostic category as well as between different ones. The presence of one type of anxiety disorder increases the likelihood of presence of another. For example, persons diagnosed as having social phobias often receive a secondary diagnosis of panic disorder. Knowing that comorbidity may be high in certain types of cases is valuable to clinicians because it alerts them to the need to probe carefully regarding the possibility of co-occurrances. For example, having been diagnosed with panic disorder, agoraphobia, or simple phobia is predictive of being diagnosed later in life as having generalized anxiety disorder.
Studies of comorbidity in anxiety & mood disorders have revealed several intriguing findings. One is that the risk of depression in individuals with chronic anxiety disorders is greater than the risk of anxiety in individuals with depressive disorders. Another is that depressive disorders are more likely to remain free of comorbid anxiety, whereas anxiety disorders are more often complicated by depression after long term follow up. Evidence of high comorbidity within a diagnostic category also leads to consideration of possible need to revise classification criteria.
