Prenatal exposure to certain antidepressants may modestly increase risk of autism spectrum disorders, study suggests

ScienceDaily (July 5, 2011) — Prenatal exposure to selective serotonin reuptake inhibitors, especially during the first trimester, is associated with a modest increase the risk of developing an autism spectrum disorder, according to a report published Online First in the Archives of General Psychiatry, one of the JAMA/Archives journals.

"The prevalence of autism spectrum disorders (ASDs) has increased over recent years," the authors write as background information in the article. "Use of antidepressant medications during pregnancy also shows a secular increase in recent decades, prompting concerns that prenatal exposure may contribute to increased risk of ASD."

To evaluate if prenatal exposure to antidepressants, including selective serotonin reuptake inhibitors (SSRIs), is associated with an increase in ASD, Lisa A. Croen, Ph.D., of Kaiser Permanente Northern California, Oakland, and colleagues examined medical records for children drawn from the Childhood Autism Perinatal Study conducted by Kaiser Permanente Medical Care Program in Northern California. The authors included 298 children with ASD (case group) and their mothers, and 1,507 control children and their mothers in the study.

Twenty mothers of children in the case group (6.7 percent) and 50 mothers of children in the control group (3.3 percent) had at least one prescription for an antidepressant in the year prior to the birth of the study child. Of the 20 case mothers who were prescribed antidepressants, 13 (65 percent) were prescribed SSRIs only, two (10 percent) were prescribed an SSRI in combination with another antidepressant and five (25 percent) were prescribed one or more non-SSRI antidepressants only. Of the 50 control mothers who were prescribed an antidepressant, 25 (50 percent) were prescribed SSRIs only, nine (18 percent) were prescribed an SSRI in combination with another antidepressant and 16 (32 percent) were prescribed one or more non-SSRI antidepressants only.

After adjusting for maternal and birth factors, mothers of children with ASD were twice as likely to have at least one antidepressant prescription in the year prior to delivery. When compared with women with no antidepressant prescription during the study period, those with a prescription for a SSRI were more than twice as likely to have a child later diagnosed with ASD. This association was not seen for the small group of women who were prescribed a non-SSRI antidepressant only.

Additionally, after adjustment for a history of depression during the year prior to delivery, SSRI exposure during the first trimester remained significantly associated with risk of ASD, as was a history of SSRI exposure at any point during the year prior to delivery. Conversely, no association was seen between risk of ASD and the indication for treatment (mother having a history of depression or any mental health disorder) for the year prior to delivery.

"Although the number of children exposed prenatally to selective serotonin reuptake inhibitors in this population was low, results suggest that exposure, especially during the first trimester, may modestly increase the risk of ASD," the authors conclude. "We recommend that our findings be considered as preliminary and treated with caution, pending results from further studies designed to address the very complex question of whether prenatal exposure to SSRIs may be etiologically linked to later diagnoses of ASDs in offspring."

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by JAMA and Archives Journals.

Journal Reference:

Lisa A. Croen; Judith K. Grether; Cathleen K. Yoshida; Roxana Odouli; Victoria Hendrick. Antidepressant Use During Pregnancy and Childhood Autism Spectrum Disorders. Archives of General Psychiatry, 2011; DOI: 10.1001/archgenpsychiatry.2011.73

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Patients who use anti-depressants are more likely to suffer relapse, researcher finds

ScienceDaily (July 19, 2011) — Patients who use anti-depressants are much more likely to suffer relapses of major depression than those who use no medication at all, concludes a McMaster researcher.

In a paper that is likely to ignite new controversy in the hotly debated field of depression and medication, evolutionary psychologist Paul Andrews concludes that patients who have used anti-depressant medications can be nearly twice as susceptible to future episodes of major depression.

Andrews, an assistant professor in the Department of Psychology, Neuroscience & Behaviour, is the lead author of a new paper in the journal Frontiers of Psychology.

The meta-analysis suggests that people who have not been taking any medication are at a 25 per cent risk of relapse, compared to 42 per cent or higher for those who have taken and gone off an anti-depressant.

Andrews and his colleagues studied dozens of previously published studies to compare outcomes for patients who used anti-depressants compared to those who used placebos.

They analyzed research on subjects who started on medications and were switched to placebos, subjects who were administered placebos throughout their treatment, and subjects who continued to take medication throughout their course of treatment.

Andrews says anti-depressants interfere with the brain's natural self-regulation of serotonin and other neurotransmitters, and that the brain can overcorrect once medication is suspended, triggering new depression.

Though there are several forms of anti-depressants, all of them disturb the brain's natural regulatory mechanisms, which he compares to putting a weight on a spring. The brain, like the spring, pushes back against the weight. Going off antidepressant drugs is like removing the weight from the spring, leaving the person at increased risk of depression when the brain, like the compressed spring, shoots out before retracting to its resting state.

"We found that the more these drugs affect serotonin and other neurotransmitters in your brain -- and that's what they're supposed to do -- the greater your risk of relapse once you stop taking them," Andrews says. "All these drugs do reduce symptoms, probably to some degree, in the short-term. The trick is what happens in the long term. Our results suggest that when you try to go off the drugs, depression will bounce back. This can leave people stuck in a cycle where they need to keep taking anti-depressants to prevent a return of symptoms."

Andrews believes depression may actually be a natural and beneficial -- though painful -- state in which the brain is working to cope with stress.

"There's a lot of debate about whether or not depression is truly a disorder, as most clinicians and the majority of the psychiatric establishment believe, or whether it's an evolved adaptation that does something useful," he says.

Longitudinal studies cited in the paper show that more than 40 per cent of the population may experience major depression at some point in their lives.

Most depressive episodes are triggered by traumatic events such as the death of a loved one, the end of a relationship or the loss of a job. Andrews says the brain may blunt other functions such as appetite, sex drive, sleep and social connectivity, to focus its effort on coping with the traumatic event.

Just as the body uses fever to fight infection, he believes the brain may also be using depression to fight unusual stress.

Not every case is the same, and severe cases can reach the point where they are clearly not beneficial, he emphasizes.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by McMaster University.

Journal Reference:

Michael C. Neale, Charles O. Gardner, Lisa J. Halberstadt, Susan G. Kornstein, Paul W. Andrews. Blue Again: Perturbational Effects of Antidepressants Suggest Monoaminergic Homeostasis in Major Depression. Frontiers in Psychology, 2011; 2 DOI: 10.3389/fpsyg.2011.00159

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Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

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