Fear, guilt and confusion often surround the use of antidepressants during pregnancy, especially for women already struggling with depression or anxiety. But a major international study published in the prestigious The Lancet Psychiatry has now delivered what researchers describe as the strongest evidence yet that commonly prescribed antidepressants during pregnancy do not cause autism or ADHD in children.

The large-scale systematic review and meta-analysis — a scientific method that combines findings from multiple studies to produce stronger conclusions — analysed data from 37 studies involving more than 600,000 pregnancies exposed to antidepressants and nearly 25 million pregnancies without such exposure. The findings challenge years of alarming headlines and public anxiety linking antidepressant use during pregnancy with neurodevelopmental disorders in children.

Researchers from the University of Hong Kong found that once important background factors such as parental mental health, genetics and family environment were taken into account, the apparent link between antidepressants and conditions such as autism spectrum disorder and attention-deficit/hyperactivity disorder (ADHD) either became extremely weak or disappeared altogether.

Before adjusting for these factors, the study initially appeared worrying. Antidepressant use during pregnancy was associated with a 35 per cent higher risk of ADHD and a 69 per cent higher risk of autism in children. But the deeper analysis told a very different story.

The same increased risks were also found among children whose fathers used antidepressants during the pregnancy period and among mothers who had taken antidepressants before conception but stopped during pregnancy. That unusual pattern strongly suggested that the medicines themselves were not driving the risk.

Instead, scientists believe the real contributors are likely to be inherited genetic vulnerabilities, underlying mental health conditions and stressful family environments.

“We know many parents-to-be worry about the potential impact of taking medication during pregnancy; our study provides reassuring evidence that commonly used antidepressants do not increase the risk of neurodevelopmental disorders such as autism and ADHD in children,” said Dr Wing-Chung Chang of the University of Hong Kong.

He added, “While all medications carry risks, so too does stopping antidepressants during pregnancy due to an increased risk of relapse. Therefore, for women with moderate-severe depression, doctors and patients must carefully weigh the potential risks and benefits.”

The study arrives at a time when depression during pregnancy is increasingly recognised as a major public health concern globally, including in India. Mental health experts say untreated depression in pregnant women can lead to poor nutrition, disturbed sleep, high stress hormone levels, self-neglect, substance abuse risk and even suicidal thoughts. In severe cases, it may also affect bonding between mother and child after birth.

Scientists have long struggled to separate the effects of antidepressants from the effects of depression itself. That distinction matters enormously.

Inside hospital clinics and psychiatric research units from Hong Kong to Europe, researchers spent years untangling complex medical records, comparing sibling studies, analysing paternal antidepressant use and examining how different social and genetic factors intersect. This painstaking process helped researchers identify what they call “confounding factors” — hidden influences that can falsely make one thing appear responsible for another.

In simple language, earlier studies may have blamed the medicine when the real driver was the underlying mental health condition or inherited genetic traits.

The new analysis particularly focused on selective serotonin reuptake inhibitors, or SSRIs, the most commonly prescribed antidepressants worldwide. These medicines work by increasing serotonin, a brain chemical linked to mood regulation.

Among mothers already diagnosed with mental health conditions, SSRIs were not associated with autism or ADHD risk.

Only older antidepressants such as amitriptyline and nortriptyline continued showing some association. However, researchers cautioned that these medicines are usually prescribed in more difficult or treatment-resistant depression cases, where patients often face more severe psychological illness and long-term stress. That makes it difficult to determine whether the medicines or the severity of the illness is responsible.

Importantly, the researchers also found no meaningful difference between high and low antidepressant doses.

Dr Joe Kwun-Nam Chan from the University of Hong Kong said the findings underline the importance of supporting both parents psychologically.

“The evidence suggests a link between either parent having a mental health condition and a slightly higher risk of ADHD or autism,” he explained. “In addition to genetic factors, this link could be explained by the home and social environment.”

That environment can include family tension, financial instability, chronic stress, emotional withdrawal or changes in parenting behaviour. Scientists increasingly believe these factors may shape early brain development in subtle ways.

Independent experts have also welcomed the findings.

Writing in an accompanying commentary, researchers Lisa Vitte, Emmanuel Devouche, and Gisele Apter from University Rouen Normandy said the study "confirms some of the pre-existing knowledge" that antidepressants "protect maternal mental health and do not harm foetal development."

They described the findings as highly significant after years of conflicting and controversial research.

Still, the authors acknowledged some limitations. Many of the studies lacked detailed information on poverty, nutrition, smoking, alcohol use, birth weight and lifestyle risks. Data about antidepressant use during specific pregnancy trimesters also remained limited.

Even so, specialists say the findings may help reduce unnecessary panic among expectant mothers who abruptly stop medicines out of fear.

Doctors caution that stopping antidepressants suddenly without medical supervision can trigger severe relapse symptoms, emotional instability and dangerous depressive episodes during pregnancy.

For millions of families worldwide, the message from the new evidence appears increasingly clear: protecting maternal mental health is not separate from protecting child health. The two are deeply connected.