Searching for moderators and mediators of pharmacological treatment effects in children and adolescents with anxiety disorders.

OBJECTIVE: To examine whether age, gender, ethnicity, type of anxiety disorder, severity of illness, comorbidity, intellectual level, family income, or parental education may function as moderators and whether treatment adherence, medication dose, adverse events, or blinded rater's guess of treatment assignment may function as mediators of pharmacological treatment effect in children and adolescents with anxiety disorders. METHOD: The database of a recently reported double-blind placebo-controlled trial of fluvoxamine in 128 youths was analyzed. With a mixed-model random-effects regression analysis of the Pediatric Anxiety Rating Scale total score, moderators and mediators were searched by testing for a three-way interaction (strata by treatment by time). A two-way interaction (strata by time) identified predictors of treatment outcome. RESULTS: No significant moderators of efficacy were identified, except for lower baseline depression scores, based on parent's (but not child's) report, being associated with greater improvement (p < .001). Patients with social phobia (p < .05) and greater severity of illness (p < .001) were less likely to improve, independently of treatment assignment. Blinded rater's guess of treatment assignment acted as a possible mediator (p < .001), but improvement was attributed to fluvoxamine, regardless of actual treatment assignment. Treatment adherence tended to be associated (p = .05) with improvement. CONCLUSIONS: In this exploratory study, patient demographics, illness characteristics, family income, and parental education did not function as moderators of treatment effect. Social phobia and severity of illness predicted less favorable outcome. Attribution analyses indicated that study blindness remained intact. The presence of concomitant depressive symptoms deserves attention in future treatment studies of anxious children.

Pediatric bupropion-induced serum sicknesslike reaction.

This reports the first 2 cases of serum sicknesslike reaction to bupropion in children (age 12 and 14). Serum sicknesslike reactions are an example of immune-complex medicated disease. The cardinal symptoms of serum sickness are fever, lymphadenopathy, arthralgias or arthritis, and urticaria. Symptoms usually resolve without long-term sequela following discontinuation of the exogenous antigen. It is likely that serum sicknesslike reactions to bupropion are either relatively rare or underrecognized and underreported. Between May 1998 and May 2001, GlaxoSmith Kline received 172 reports of seizures (a well-known adverse drug reaction) and only 37 reports of serum sicknesslike reactions (Wooltorton 2002). We do not know if children and adolescents are more prone than adults to develop serum sicknesslike reactions to bupropion. Luckily, the reported cases of serum sicknesslike reactions to bupropion have not caused irreversible morbidity or mortality. Nevertheless, the symptoms are painful, temporarily disfiguring and disabling, and warrant prompt medical attention. Parents and patients should be educated about this potential side effect at the onset of treatment, because symptoms are similar to many infectious childhood illnesses, and the treatment of serum sicknesslike reactions to bupropion should include the discontinuation of bupropion.

Treatment of pediatric anxiety disorders: an open-label extension of the research units on pediatric psychopharmacology anxiety study.

BACKGROUND: An 8-week placebo-controlled study, the Research Units on Pediatric Psychopharmacology Anxiety Study, documented beneficial effects of fluvoxamine in the treatment of pediatric social anxiety, separation anxiety, or generalized anxiety disorders. Following completion of this study, participants were invited to enter a 6-month open-label treatment phase designed to examine three issues: (a) long-term maintenance of response in fluvoxamine responders, (b) acute response to fluoxetine in fluvoxamine nonresponders, and (c) acute response to fluvoxamine in placebo nonresponders. METHODS: Participants aged 6-17 years meeting criteria for social anxiety, separation anxiety, or generalized anxiety disorders previously treated in an 8-week placebo-controlled trial (n = 128) were offered open treatment. Changes in symptoms of anxiety during open treatment were assessed in three groups: (a) fluvoxamine responders maintained on fluvoxamine, (b) fluvoxamine nonresponders changed to fluoxetine, and (c) placebo nonresponders changed to fluvoxamine. Response was defined based on Clinical Global Impression criteria. RESULTS: During 6 months of continued open treatment, anxiety symptoms remained low in 33 of 35 (94%) subjects who initially responded to fluvoxamine. Among 14 fluvoxamine nonresponders switched to fluoxetine, anxiety symptoms appeared significantly improved in 10 (71%) subjects. Finally, among 48 placebo nonresponders, 27 (56%) showed clinically significant improvement in anxiety on fluvoxamine. CONCLUSION: The current findings concerning extended treatment of pediatric anxiety disorders are only preliminary, because treatment was uncontrolled. Results suggest that an initial fluvoxamine response is likely to be retained with continued treatment, that some fluvoxamine nonresponders may respond to fluoxetine, and that some placebo nonresponders may respond to fluvoxamine.

The pharmacological treatment of anxiety disorders in children and adolescents.

As the recognition of paediatric and adolescent anxiety disorders improves, so does the number of recommended treatments. Newer medications (chiefly serotonergic antidepressants) have emerged as the pharmacological treatment of choice and have largely replaced benzodiazepines and tricyclic antidepressants (TCAs) for these disorders. This review will focus on placebo-controlled and open-label studies concerning the treatment of anxiety in children and adolescents, comparing data from newer antidepressant medications (plus buspirone) with data on TCAs and benzodiazepines in this population. There are few randomised, placebo-controlled trials of medications for anxiety in children and adolescents, with most data coming from open-label trials and case series. Moreover, there are no studies comparing pharmacological versus behavioural treatments. Most recent data concerning the efficacy of selective serotonin reuptake inhibitors suggests that these agents will be effective and safe in the treatment of paediatric anxiety disorders. The potential side effect profiles of these newer agents also makes them an attractive first choice for anxiety when compared to the benzodiazepines or TCAs, each of which poses its own potentially serious adverse effects. More research is needed in the area of psychopharmacological treatments for paediatric and adolescent anxiety, not only to substantiate the current beliefs that serotonergic agents are effective and safe but to pinpoint the factors that might predict responses to particular agents or classes of medications. Future investigations should focus on treatments which have already proven effective for adult anxiety disorders (both medications and psychotherapies), given the apparent links between paediatric and adult anxiety disorders.