medwireNews: Comorbid anxiety may flag those patients with bipolar depression who are in particular need of intensive psychotherapy, suggest findings from the Systematic Treatment Enhancement Program for Bipolar Disorder.
The randomized controlled trial showed that patients with bipolar disorder were less likely to recover with collaborative care if they had comorbid anxiety – whether current or not – whereas this did not affect their response to intensive psychotherapy.
“Those with past or present anxiety disorders appeared to need the more intensive intervention to recover,” says the team, led by Thilo Deckersbach (Massachusetts General Hospital, Boston, USA).
This was not observed for all anxiety disorders, however. The effect size favoring response to psychotherapy was medium to large for generalized anxiety disorder (number needed to treat [NNT]=3.03) and small to medium for post-traumatic stress disorder (NNT=5.56), but only small for panic disorder, social phobia, and obsessive compulsive disorder.
And the effect was strongest when only one anxiety disorder was present, the researchers note, saying that patients with multiple anxiety disorders are likely to have more treatment-resistant symptoms that fail to respond even with intensive psychotherapy.
“As such, anxiety comorbidity may emerge as an important variable for the allocation of clinical resources, identifying individuals for whom intensive psychotherapy for bipolar disorder may be particularly important for treatment response,” Deckersbach and co-workers comment in The American Journal of Psychiatry.
Among 269 patients with bipolar depression studied, 177 had a comorbid lifetime anxiety disorder. The response rate for 99 patients assigned to intensive psychotherapy, involving cognitive behavioral therapy, interpersonal social rhythm theory, and family-focused therapy, was 66%, compared with just 49% for the 78 patients assigned to brief collaborative care, which drew on known psychosocial strategies. This difference corresponded to a NNT of 5.88.
There was no difference between the two treatments for the 92 patients with bipolar depression who did not have comorbid anxiety, with response rates of 64% with psychotherapy and 62% with collaborative care.
The researchers note that there were baseline differences between patients with and without comorbid anxiety with regard to medication, and further studies would need to tease out the relative effects of anxiety pathology and medication strategies on treatment outcome.
Nevertheless, they conclude: “Different psychosocial approaches may be needed for those with and without anxiety.”
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