'Baby brain' may be more about mood than memory

'Baby brain' is one of the most widely repeated ideas about pregnancy and new motherhood: women report forgetfulness, disorientation and a shorter attention span, yet objective testing has never told a consistent story. One proposed explanation is mood, since depressive and anxiety symptoms are common in the perinatal period and are known to affect thinking. If mood disturbance drives the cognitive complaints, that changes both how the complaints should be interpreted and where support should be aimed. This review set out to map the relationship between perinatal depressive and anxiety symptoms and cognitive functioning across memory, attention and cognitive flexibility.

Following standard systematic review guidelines, the authors searched three databases and included 42 studies examining links between depressive or anxiety symptoms and cognition during pregnancy or after birth. Cognition was assessed through both self-reported complaints and objective neuropsychological tasks covering working memory, verbal memory, recognition memory, autobiographical memory, attention and cognitive flexibility. Where at least three comparable studies existed, exploratory pooled analyses were run and reported separately. The authors also catalogued the methods used, noting that most studies captured one moment in time, relied on self-reported symptom measures and rarely assessed anxiety.

The most consistent result was that women with more depressive symptoms reported more cognitive complaints, a pattern seen across six studies. Objective testing told a different story: results were inconsistent for working memory across 11 studies, for attention across 24, and for cognitive flexibility across 5. Autobiographical memory showed an association with depressive symptoms, but that rested on only 3 studies. Verbal memory, examined in 8 studies, and recognition memory, examined in 2, showed no association with depressive or anxiety symptoms at all. In short, feeling impaired was reliably linked to mood; measurably being impaired was not reliably found.

This gap between perceived and measured performance echoes a wider pattern in cognition research, where subjective complaints often track mood more closely than test scores do. The authors suggest mood, sleep, mental load and sociocultural narratives about motherhood may all shape how women judge their own thinking. The evidence base has clear limits: mostly one-off snapshots, varied tasks that bear little resemblance to daily life, and almost no attention paid to anxiety. Longer-term studies using more realistic tasks are needed before anyone can say whether, when and for whom genuine cognitive change occurs in the perinatal period.

If pregnancy or new motherhood has you feeling foggy, this is a reason to suspect the fog says more about mood, sleep and mental load than about your brain's actual capacity, which in objective tests mostly held up. It is also a reason to take persistent low mood during this period seriously in its own right, since it was the factor most consistently tied to feeling cognitively worse. What the evidence cannot yet do is rule genuine cognitive change in or out; the studies disagreed too much among themselves for that.