A meta-analysis of studies on the effects of antidepressants on children and teenagers has found almost no benefits relative to placebos. A small benefit was found for fluoxetine, marketed as Prozac, but this was sufficiently borderline as to be open to question. The findings come on top of recent research showing these drugs are associated with a doubling of the risk of suicide and aggression in the same age groups. 

Dr. Andrea Cipriani of the University of Oxford looked at peer-reviewed studies on the effects of antidepressants for children and adolescents diagnosed with major depressive disorder. In The Lancet, Dr. Cipriani and his co-authors write: “Trials recruiting participants with treatment-resistant depression, treatment duration of less than 4 weeks, or an overall sample size of less than ten patients were excluded.” This left 34 trials of 14 drugs on a total of 5,260 participants.

After taking the quality of evidence presented into account, the authors report: “Only fluoxetine was statistically significantly more effective than placebo.” They conclude: “When considering the risk–benefit profile of antidepressants in the acute treatment of major depressive disorder, these drugs do not seem to offer a clear advantage for children and adolescents.”

Substantial differences were found between the drugs, but mostly in the form of their harm. Imipramine, venlafaxine, and duloxetine showed enough side effects to be frequently discontinued, while venlafaxine had a disturbingly strong association with suicidal thoughts. Some of the other drugs lacked sufficient data on this point to reach conclusions. Considering that 22 of the trials were funded by pharmaceutical companies, independent assessments may have been worse.

The findings may come as a shock to teenagers and their families. However, for many years a growing body of medical researchers and therapists have been expressing alarm at the widespread prescription of Selective Serotonin Re-uptake Inhibitors (SSRIs) to people whose brains have not fully developed.

These drugs are expensive to bring to market, but so cheap to produce once approved that pharmaceutical companies have a huge incentive to expand their market as much as possible. This can lead to pushes for prescriptions to people they won't help

The length companies will go to in order to gain approval for SSRIs to be prescribed to adolescents was revealed last year. A reevaluation of the notes from a clinical trial found 11 teenagers on the SSRI paroxetine had attempted suicide, something mysteriously left out of the original report.

“Without access to individual-level data it is difficult to get accurate effect estimates and we can't be completely confident about the accuracy of the information contained in published and unpublished trials,” Cipriani said in a statement. “It has been widely argued that there needs to be a transformation of existing scientific culture to one where responsible data sharing should be the norm.”

Professor Jon Jureidini of the University of Adelaide published an accompanying comment in the same edition.

Jureidini told IFLScience that while many young people improve after being given SSRIs, the drugs are seldom responsible. “Some of it is reversion to the mean, some of it is placebo effect...The biggest impact factor is the relationship with the therapist,” he said. “If a doctor can establish this it may well be enough [to produce improvement] without prescribing drugs.”

Part of the problem, Jureidini argued, is that depression is a “description masquerading as an explanation”, and that many people showing depressive symptoms are in need of changes to their “psychosocial circumstances” rather than a pill, but this is harder for a doctor to achieve.