# Understanding How Antidepressants and Maternal Depression During Pregnancy Affect Children's Brain Development This study followed 240 children of mothers with depression who took either venlafaxine (a serotonin-norepinephrine reuptake inhibitor) or an SSRI (selective serotonin reuptake inhibitor) during pregnancy, mothers with untreated depression, and healthy nondepressed mothers. Researchers found that antidepressant exposure itself did not predict children's intelligence or behavior — instead, maternal IQ and child sex predicted IQ, while the severity of maternal depression predicted behavioral outcomes. Children of depressed mothers had full-scale IQs of 105–108, significantly lower than the 112 seen in children of nondepressed mothers. The study suggests that factors other than antidepressant exposure during pregnancy strongly predict children's intellect and behavior. # Understanding How Antidepressants and Maternal Depression During Pregnancy Affect Children's Brain Development ## Table of Contents - Key Points - Background: A Difficult Decision for Pregnant Women with Depression - Why This Study Was Needed - Study Methods: How the Research Was Conducted - The Four Groups of Mothers and Children - How Children's Intelligence and Behavior Were Evaluated - Key Findings: Intelligence (IQ) Results - Key Findings: Behavioral Outcomes - What Factors Actually Predicted Child Development? - Postpartum Depression in the Mothers - Neonatal Adaptation Signs in Exposed Newborns - Clinical Implications: What This Means for Patients - Study Limitations: What This Study Couldn't Prove - Recommendations for Patients - Frequently Asked Questions - Source Information ## Key Points - In a study of 240 children, antidepressant exposure during pregnancy did not independently predict IQ or behavior; maternal IQ and child sex predicted IQ, and depression severity predicted behavior. - Children of depressed mothers had full-scale IQs of 105–108, lower than the 112 seen in children of nondepressed mothers, whether or not the mother took antidepressants. - Untreated depression during pregnancy strongly predicted postpartum depression: 79.6% of untreated women had a depressive episode in the first year after delivery. - Do not stop antidepressants abruptly without consulting your doctor; discuss all treatment options with your healthcare provider. ## Background: A Difficult Decision for Pregnant Women with Depression Treating depression during pregnancy involves a delicate balancing act. Doctors must weigh the potential risks of antidepressant medications to the developing baby against the known harmful effects of untreated maternal depression on both the mother and the fetus. Two types of antidepressants are commonly prescribed to pregnant women with depression: **venlafaxine**, which is a serotonin and norepinephrine reuptake inhibitor (SNRI), and **selective serotonin reuptake inhibitors (SSRIs)**, a class that includes medications such as fluoxetine (Prozac), sertraline (Zoloft), paroxetine (Paxil), citalopram (Celexa), and fluvoxamine (Luvox). These medications are known to cross the human placenta and thus may potentially interfere with fetal brain development. At the same time, untreated maternal depression itself is associated with adverse outcomes. Research has linked untreated depression during pregnancy to obstetric complications, stillbirth, prematurity, impaired fetal growth, malformations, cognitive deficits in children, and later psychopathology (mental health problems). The central scientific challenge is separating the effects of the mother's depression from the effects of the medication used to treat it. This study was designed to do exactly that. ## Why This Study Was Needed Previous studies examining the reproductive safety of antidepressants had significant limitations. Many were not specifically designed to assess intellectual outcomes in children. Others lacked appropriate comparison groups, had small sample sizes, and were therefore underpowered — meaning they were too small to reliably detect differences. Most importantly, earlier research often failed to account for significant confounders (factors that can skew results), including maternal depression itself, drug abuse, socioeconomic status, and other environmental and genetic factors. This study, conducted by researchers at the **Hospital for Sick Children in Toronto**, was designed to address these gaps. It is the first study to examine, as its primary outcome, the intelligence of children born to mothers taking antidepressants during pregnancy compared with children of mothers with untreated depression and children of nondepressed mothers. ## Study Methods: How the Research Was Conducted The researchers drew participants from the **Motherisk program** at the Hospital for Sick Children in Toronto, a prospectively collected database containing information about pregnant women who sought counseling on the pregnancy safety of medications, including antidepressants and nonteratogens (medications not known to cause birth defects). Between 2001 and 2006, a total of **608 women** called Motherisk regarding antidepressant counseling for depression. Of these, 381 did not meet the inclusion criteria for the study. An additional 17 callers who took venlafaxine during pregnancy, 19 who took SSRIs during pregnancy, and 13 who went untreated during pregnancy were unable to be located or refused to participate. The researchers analyzed the intake forms of the women who were lost to follow-up or declined to participate. Their medical and psychiatric histories, medications, concomitant disorders, and demographic characteristics did not differ from those of the included cohort — meaning the women who completed the study were representative of the larger group. Mothers were excluded if they had been exposed to polytherapy (multiple medications) for depression or known teratogens (substances that cause birth defects, such as antiepileptic drugs), had substance abuse problems (such as alcohol use disorders), had other psychiatric conditions (such as schizophrenia), gave birth prematurely (before 37 weeks of gestation), had medical conditions unrelated to in utero exposure that could affect cognitive outcomes (such as postnatal head trauma or encephalitis), or had inadequate English proficiency. Mothers and children with such conditions were also excluded. ## The Four Groups of Mothers and Children The study included four groups of mother-child pairs, totaling **240 children**: 1. **Group 1 (Venlafaxine):** 62 children born to depressed women who took venlafaxine during pregnancy 1. **Group 2 (SSRI):** 62 children born to depressed women who took SSRIs during pregnancy 1. **Group 3 (Untreated depression):** 54 children born to depressed women who discontinued pharmacotherapy before conception and remained untreated during pregnancy 1. **Group 4 (Nondepressed healthy):** 62 children born to nondepressed, healthy pregnant women who called Motherisk to inquire about nonteratogenic exposures (e.g., acetaminophen) and had no psychiatric history The SSRI group included 11 women exposed to sertraline, 20 exposed to paroxetine, 15 exposed to citalopram, 15 exposed to fluoxetine, and 1 exposed to fluvoxamine. Venlafaxine defined daily doses ranged from 0.25 to 3.75, while SSRI defined daily doses ranged from 0.40 to 4.00. Of the 124 women exposed to antidepressants, **81 were exposed throughout pregnancy**, 21 in the first trimester only, 4 in the first and second trimesters, 2 in the second trimester only, 11 in the second and third trimesters, and 5 in the third trimester only. The median duration of antidepressant use during pregnancy was **30 weeks**, with a range of 4 to 42 weeks. ### Maternal Characteristics Across the Groups The four groups of mothers were very similar in many ways. Maternal age at delivery averaged approximately 32 years across all groups. Maternal IQ, as measured by the Wechsler Abbreviated Scale of Intelligence, was also similar: 109.14 in the venlafaxine group, 108.16 in the SSRI group, 110.02 in the untreated depression group, and 110.37 in the nondepressed group. These differences were not statistically significant. Women in all three depression groups had been depressed for a similar number of years (approximately 10 years). However, there were some important differences: - Women in the untreated group (group 3) received fewer years of pharmacotherapy for depression (6.71 years) than those in the venlafaxine group (9.03 years) or SSRI group (8.64 years), with the difference between groups 1 and 3 being statistically significant - Women in the untreated group experienced **more severe depression during pregnancy** (4.55 on a 1–10 visual analogue scale) compared with the venlafaxine group (2.46) and SSRI group (3.54), with a significant difference between groups 1 and 3 - At the time of child testing, all women with depression had similar scores on the Center for Epidemiologic Studies Depression Scale (CES-D), a 20-item self-report measure scored from 0 to 60, with scores of 16 and above representing clinically significant depressive symptoms Cigarette use was low across groups (4.9%–8.3%), as was alcohol use (0%–5.0%). Household income of $50,000 or more was reported by 75.4%–88.3% of mothers, and the vast majority (92.5%–98.3%) were rated as having medium-or-above socioeconomic status. ## How Children's Intelligence and Behavior Were Evaluated All children were tested individually by a psychometrist who was **masked to group affiliation** — meaning the tester did not know which group each child belonged to, which prevents bias in scoring. Testing occurred at a single time point when children were between the ages of **3 years and 6 years, 11 months**. Intelligence was evaluated using the **Wechsler Preschool and Primary Scale of Intelligence – Third Edition**, which provides three summary scores: - **Full-scale IQ:** represents general intellectual functioning - **Verbal IQ:** represents verbal reasoning and comprehension - **Performance IQ:** represents fluid reasoning, spatial processing, and visual-motor integration Behavioral profiles were assessed using two tools completed by the mother: - The **Child Behavior Checklist (CBCL)**, which provides scores on three broad factors: internalizing problems (depressed affect and withdrawn behaviors), externalizing problems (aggressive and delinquent behaviors), and total problems (which summarizes both) - The **Conners' Parent Rating Scale**, whose global index and DSM-IV total symptom subscales were used to evaluate attention deficit hyperactivity disorder (ADHD) and other DSM-IV symptoms Scores on the CBCL and Conners' scales are reported as T-scores (mean = 50, SD = 10), with higher scores indicating more behavior problems. Anthropometric measurements (height, weight, head circumference) were obtained for each child, and a written health report was obtained from each child's physician. ## Key Findings: Intelligence (IQ) Results The intelligence test results revealed several important findings. The **full-scale IQs** of the four groups were: - Venlafaxine group: **105** - SSRI group: **105** - Untreated depression group: **108** - Nondepressed healthy group: **112** Children in the nondepressed group had significantly higher full-scale and verbal IQs than children in both the venlafaxine and SSRI groups, and significantly higher performance IQs than the SSRI group. The difference between the nondepressed group and the venlafaxine group was statistically significant at the p≤0.001 level for full-scale and verbal IQ, and the differences between the nondepressed group and SSRI group were significant at p≤0.05. The **verbal IQs** were 106 (venlafaxine), 107 (SSRI), 109 (untreated), and 113 (nondepressed). The **performance IQs** were 103, 102, 105, and 108, respectively. Critically, there was **no statistically significant difference** in full-scale, verbal, or performance IQ between the untreated depression group and either the venlafaxine or SSRI-exposed groups. In other words, taking antidepressants during pregnancy did not appear to lower children's IQ beyond the effect of maternal depression itself. Similarly, there was no difference in full-scale, verbal, or performance IQ between the children in the venlafaxine and SSRI groups — meaning both types of medication were associated with comparable cognitive outcomes. ### Timing of Exposure Did Not Matter The study examined whether the timing of antidepressant exposure during pregnancy made a difference. Children with **first-trimester exposure** had IQs similar to those of children exposed throughout pregnancy: - Full-scale IQ: 103 (first-trimester) versus 105 (throughout pregnancy) - Verbal IQ: 106 versus 107 - Performance IQ: 99 versus 103 None of these differences were statistically significant. This suggests that the timing of exposure during pregnancy did not dramatically alter cognitive outcomes. ### Sex Differences in IQ In all groups, **girls had statistically significantly higher values on all three IQ measures than boys**. ## Key Findings: Behavioral Outcomes Children in all three groups exposed to maternal depression (venlafaxine, SSRI, and untreated) had more clinically significant behavioral problems as assessed by the CBCL and Conners' scales than children of nondepressed mothers. The study looked at the proportion of children scoring in the clinically significant range — defined as a total score of 64 or above on the CBCL and 65 or above on the Conners' Parent Rating Scale. The difference among groups reached statistical significance on the **Conners' Parent Rating Scale total problems score** (p = 0.03). The three groups exposed to maternal depression had consistently, but not always significantly, higher rates of most problematic behaviors than the children of nondepressed mothers. Among the antidepressant-exposed children, clinically significant behavior problems (measured by both the CBCL and Conners' scales) were **approximately twice as common in those with poor neonatal adaptation signs** as compared to the other antidepressant-exposed children — specifically, 14.3% to 21.4% versus 6.5% to 11.4%. ## What Factors Actually Predicted Child Development? The researchers used hierarchical linear regression analyses to determine which factors truly predicted cognitive and behavioral outcomes. This statistical technique allows researchers to account for multiple variables simultaneously and identify which factors are independently associated with outcomes. The results were striking: ### Predictors of IQ - **Maternal IQ significantly predicted all three child IQ outcomes** (full-scale, verbal, and performance IQ). For full-scale IQ, maternal IQ had a beta value of 0.42 (p<0.01) - **Child sex significantly predicted full-scale and verbal IQ**, with girls scoring higher - **Antidepressant dose and duration during pregnancy did NOT predict any cognitive outcome** - Severity of maternal depression during pregnancy and at testing did not predict cognitive outcomes - Child's age at testing did not predict cognitive outcomes - After controlling for other factors, **group membership (which medication, or no medication) did not predict cognitive outcomes** No significant correlations were found between dose or duration of antidepressant treatment during pregnancy and cognitive and behavioral outcomes (r = 0.01–0.12 for dose, and r = –0.08 to 0.14 for duration of treatment). There was, however, a negative correlation between duration of antidepressant treatment and severity of depression in pregnancy (r = –0.23, N = 124, p = 0.01), meaning that women who took antidepressants longer tended to have less severe depression during pregnancy. ### Predictors of Behavior - **Severity of maternal depression during pregnancy significantly predicted all behavioral outcomes**, including CBCL internalizing, externalizing, and total problem scores - **Severity of maternal depression at the time of child testing also predicted behavior**, including the Conners' Parent Rating Scale total index - The Conners' DSM total symptoms score was predicted by severity of maternal depression during pregnancy alone - **Dose and duration of antidepressant treatment during pregnancy did NOT predict behavioral outcomes** - Child sex, child age at testing, and maternal IQ were not predictors of behavioral outcomes ### Mother-Child IQ Differences The difference between maternal IQ and the child's full-scale IQ was predicted by maternal IQ alone. Child sex, child age at testing, dose and duration of antidepressant exposure during pregnancy, and severity of depression during pregnancy and at testing did not predict this outcome. The differences between maternal IQ and child IQ were similar across all four groups, suggesting no treatment effect on this measure. ## Postpartum Depression in the Mothers One of the most important findings of this study relates to the mothers' mental health after delivery. A depressive episode in the first year following delivery was experienced by: - **79.6% of women in the untreated group** (group 3) - 66.1% of women in the SSRI group (group 2) - 50.0% of women in the venlafaxine group (group 1) - 3.2% of women in the nondepressed group (group 4) This difference was highly statistically significant (p<0.001). Furthermore, **72.2% of the untreated women** initiated pharmacotherapy for depression within that first year after delivery. This finding underscores a serious clinical concern: **depression during pregnancy is a significant risk factor for postpartum depression**. Women who went untreated during pregnancy were far more likely to experience a depressive episode after their baby was born. ## Neonatal Adaptation Signs in Exposed Newborns Among the children exposed to antidepressants, **11.3% received a diagnosis of poor neonatal adaptation signs**. These are a series of behaviors observed in the newborn following gestational antidepressant exposure, including: - Jitteriness - Rapid breathing (tachypnea) - Poor muscle tone - Respiratory distress - Weak or absent cry - Desaturation (low oxygen levels) on feeding Importantly, the full-scale, verbal, and performance IQs of children who exhibited poor neonatal adaptation signs were **not different** from those of the other children exposed to antidepressants. This suggests that neonatal adaptation difficulties did not have lasting effects on cognitive development in this study population. Children from all four groups did not differ in gestational age (averaging approximately 39 weeks) or birth weight (ranging from 3,443 grams in the venlafaxine group to 3,614 grams in the untreated depression group). All children had similar anthropometric measurements, including height percentile, weight percentile, and head circumference percentile. Children in the nondepressed group encountered nonsignificantly fewer neonatal complications. The children in the untreated depression group were tested at an older age (55.18 months on average) than children in the other groups (46.78 to 47.39 months), a difference that was statistically significant. However, this did not affect the overall findings. ## Clinical Implications: What This Means for Patients This study provides important reassurance and guidance for pregnant women with depression and their healthcare providers. Several key messages emerge: **First, antidepressant exposure during pregnancy did not independently predict children's IQ or behavior.** The study found that maternal IQ and child sex were the strongest predictors of child IQ, while the severity of maternal depression was the strongest predictor of behavioral outcomes. Dose and duration of antidepressant treatment during pregnancy did not predict any cognitive or behavioral outcome. **Second, untreated maternal depression carries its own risks.** Children of depressed mothers (whether treated or untreated) had lower IQs than children of nondepressed mothers, and higher rates of problematic behaviors. This suggests that depression itself, and possibly the genetic and environmental factors associated with it, plays a significant role in child development. **Third, untreated depression during pregnancy strongly predicts postpartum depression.** The finding that nearly 80% of untreated women experienced a depressive episode in the first year after delivery — compared with 50% of venlafaxine-treated women — highlights the importance of adequate treatment during pregnancy for the mother's own mental health. **Fourth, children of depressed mothers may be at risk for future psychopathology.** The higher rates of behavioral problems observed in these children, regardless of whether their mothers were treated, suggest that maternal depression may be a risk factor for mental health problems in children. This is consistent with a substantial body of research showing that children of depressed parents are at increased risk for emotional and behavioral difficulties. ## Study Limitations: What This Study Couldn't Prove While this study is rigorous, it has important limitations that should be considered: - **Observational design:** Because women were not randomly assigned to treatment groups, the study cannot prove cause and effect. Women who took antidepressants differed from those who did not in ways that may influence child outcomes - **Confounding by depression severity:** Women in the untreated group had more severe depression during pregnancy than those in the venlafaxine and SSRI groups, which could have affected the comparisons - **Limited age range:** Children were assessed at a single time point between ages 3 and 6 years, 11 months. Longer-term follow-up into school age and adolescence would be needed to determine whether these findings persist - **Sample size considerations:** While the sample of 240 mother-child pairs is substantial, the power calculation was designed to detect an 8-point IQ difference. Smaller differences might have gone undetected - **Specific medication effects:** The SSRI group included several different medications (sertraline, paroxetine, citalopram, fluoxetine, fluvoxamine), and the study may not have been powered to detect differences between individual SSRIs - **Maternal reports of behavior:** Behavioral assessments relied on maternal reports, which could be influenced by the mother's own depression status ## Recommendations for Patients Based on this study and the broader medical literature, the following recommendations are reasonable for pregnant women with depression and their healthcare providers: 1. **Do not stop antidepressants abruptly without consulting your doctor.** This study found that antidepressant exposure during pregnancy was not associated with lower IQ or worse behavioral outcomes in children. However, untreated depression carried significant risks, including a nearly 80% rate of postpartum depression 1. **Discuss all treatment options with your healthcare provider.** The decision to take medication during pregnancy should be made jointly with your doctor, considering the severity of your depression, your medical history, and your personal values and preferences 1. **Recognize that depression itself may affect child development.** Both treated and untreated maternal depression were associated with lower child IQ compared with children of nondepressed mothers. This suggests that depression — whether through genetics, environmental factors, or both — is itself a relevant factor in child development 1. **Seek treatment for postpartum depression promptly.** Given the very high rates of postpartum depression among women who were depressed during pregnancy, close monitoring and early intervention after delivery are essential 1. **Consider the whole picture.** This study found that maternal IQ and child sex were the strongest predictors of child IQ. Parents should remember that many factors contribute to a child's intellectual and behavioral development 1. **Watch for neonatal adaptation signs.** If your baby was exposed to antidepressants during pregnancy, your healthcare team will monitor for poor neonatal adaptation signs in the first days after birth. While these signs occurred in about 11% of exposed newborns, they were not associated with lower IQ in this study ## Frequently Asked Questions ### I'm pregnant and taking an antidepressant. Will it lower my child's IQ? In a study of 240 children, antidepressant exposure during pregnancy did not independently predict IQ. Children of mothers who took venlafaxine or SSRIs had full-scale IQs of 105, while children of untreated depressed mothers scored 108 and children of nondepressed mothers scored 112. Maternal IQ and child sex were the strongest predictors of child IQ. ### What factors actually predicted children's behavior in this research? The severity of maternal depression during pregnancy significantly predicted all behavioral outcomes, including internalizing, externalizing, and total problem scores. Severity at the time of child testing also predicted behavior. Antidepressant dose and duration did not predict behavioral outcomes. Children of depressed mothers had more clinically significant behavior problems than children of nondepressed mothers. ### I'm pregnant and depressed — should I get a second opinion before starting or stopping an antidepressant? A second opinion is reasonable when you are deciding whether to continue, start, or stop an antidepressant during pregnancy. This research found antidepressant exposure did not independently predict children's IQ or behavior; maternal IQ and child sex predicted IQ, and severity of maternal depression predicted behavior. Untreated depression carried a high rate of postpartum depression. A second opinion can help weigh your depression severity, history, and preferences. Do not stop antidepressants abruptly without consulting your doctor. Diagnostic Detectives Network provides independent expert second opinions. ## Source Information **Original Article Title:** Neurodevelopment of Children Following Prenatal Exposure to Venlafaxine **Authors:** Irena Nulman, M.D., Gideon Koren, M.D., Joanne Rovet, Ph.D., Maru Barrera, Ph.D., Ariel Pulver, B.A., David Streiner, Ph.D., and Brian Feldman, M.D. **Journal:** The American Journal of Psychiatry, 2012; Volume 169, Issue 11, pages 1165–1174. This article was featured in that month's AJP Audio, discussed in an editorial by Dr. Steiner, and provided Clinical Guidance. **Study Location:** Motherisk Program, Hospital for Sick Children, Toronto, Canada. This patient-friendly article is based on peer-reviewed research. It is intended for educational purposes and does not constitute medical advice. Pregnant women with depression should discuss their individual treatment options with their healthcare providers. --- Publisher: Diagnostic Detectives Network (https://diagnosticdetectives.com) — independent multi-expert medical second opinions, worldwide, private-pay. Author byline: Anton Titov, MD, PhD. Contact: https://diagnosticdetectives.com/pages/contact Canonical page: https://diagnosticdetectives.com/products/understanding-how-antidepressants-and-maternal-depression-during-pregnancy-affect-childrens-brain-development