[Safety of selective serotonin reuptake inhibitor antidepressants in children and adolescents]

Better tolerability of St. John's wort extract WS 5570 compared to treatment with SSRIs: a reanalysis of data from controlled clinical trials in acute major depression

Selective serotonin reuptake inhibitors (SSRIs) like paroxetine have replaced older antidepressants mainly because of a more favorable safety profile, but they are still associated with burdensome side effects. We investigate the tolerability of St. John's wort extract WS 5570, a herbal antidepressant with proven efficacy, in comparison to paroxetine and other SSRIs and placebo. A reanalysis was performed based on the original data from four controlled clinical trials during which 1661 outpatients with major depression (Diagnostic and Statistical Manual of Mental Disorders, 4th Edition criteria) received between 600 and 1800 mg/day WS 5570 (n=1264), 20 or 40 mg/day paroxetine (n=126), or placebo (n=271) for 6 weeks. For single and grouped adverse events, the risk ratios for treatment group comparisons were determined along with their 95% confidence intervals, including comparisons with published data for SSRIs. Across the four trials, the percentage of patients with any adverse events under WS 5570 exposition was comparable with placebo [risk ratio (95% confidence interval): 1.1 (0.9-1.3) in favor of WS 5570] and significantly lower than for paroxetine [2.4 (2.1-2.8)]. Compared with the herbal extract adverse event rates under paroxetine were between 10 and 38-fold higher (point estimates) in five out of seven symptom clusters inspected. WS 5570 was devoid of effects of sedation, anticholinergic reactions, gastrointestinal disturbances, and sexual dysfunction often found during treatment with SSRIs and other synthetic antidepressants. In conclusion, WS 5570 exhibits substantially lower incidence rates of adverse events than paroxetine and other SSRIs.

[Antidepressant use in children and adolescents]

Relative to placebo, selective serotonin reuptake inhibitors (SSRI) are efficacious for paediatric affective disorders, although their clinical effects appear relatively modest in major depressive disorder, intermediate in obsessive-compulsive disorder, and stronger in anxiety disorders. If SSRIs modestly increase the risk of occurrence of suicidal ideation and behavior, several studies show that their use is associated with a significant decrease in the suicide rates in children and adolescents, probably because of their efficacy, compliance, and low toxicity in overdose.

The effect of increased serotonergic neurotransmission on aggression: a critical meta-analytical review of preclinical studies

RATIONALE

The role of serotonin (5-HT) on aggression has been extensively studied; nonetheless, the role of this neurotransmitter in aggression is still inconclusive.

OBJECTIVES

The current meta-analytical review investigated the role of increased 5-HT neurotransmission in aggression.

METHODS

Preclinical studies using serotonin reuptake inhibitors, 5-hydroxytryptophan, L-tryptophan, or serotonin (5-HT) to increase 5-HT levels were included in this meta-analysis. An overall effect of serotonin on aggression was calculated, and the role of several moderator variables was analyzed.

RESULTS

A total of 218 effect sizes revealed that increased 5-HT had an overall significant inhibitory effect on aggression (r = 0.3). The results showed that increased 5-HT had the strongest inhibitory effect on aggression when (1) a specific strain or species (e.g., Long Evans) was used; (2) aggression was offensive or predatory and/or induced by administration of 5,7-dihydroxytryptamine or p-chlorophenylalanine; (3) zimelidine, sertraline, L-tryptophan, citalopram, or 5-HT were used to increase 5-HT; (4) treatment was acute; (5) long chronic treatment durations were used; and (6) time between last injection and behavior testing was within 8 h before or after peak plasma concentration of drug. In contrast, the results revealed that increased-5-HT-facilitated aggression could be predicted when (1) Wistar rats, (2) social isolation or stress to induce aggression, and/or (3) animals treated for less than 3 weeks were used.

CONCLUSIONS

Although 5-HT has an overall inhibitory effect on aggression, the animal's genetic background, drug, treatment time, aggression inducing paradigm, and aggression type are critical variables that influence and modify this effect.