People with bipolar disorder who experienced childhood maltreatment tend to perform worse on a range of cognitive tasks, according to a major review of existing research. The findings suggest that early adversity leaves a measurable mark on thinking and memory that persists well into adulthood.
The systematic review and meta-analysis, published in Acta Psychiatrica Scandinavica, pooled data from 20 studies involving 2,457 people with bipolar disorder. Researchers examined how different types of childhood maltreatment, including physical abuse, sexual abuse, emotional abuse, physical neglect, and emotional neglect, relate to six areas of cognitive functioning.
Overall childhood maltreatment was significantly associated with poorer performance in global cognition and IQ, attention and processing speed, and verbal memory and learning. Physical and sexual abuse, as well as physical neglect, were also linked to weaker working memory and executive functions such as planning and problem-solving. Emotional neglect was the only subtype that showed no clear association with any cognitive domain.
The effects observed were small in magnitude but consistent across multiple studies with low variability in results. Researchers note that even modest cognitive differences can meaningfully affect daily functioning, employment, and quality of life for people already living with the burden of bipolar disorder.
One area where childhood maltreatment showed no significant effect was social cognition, which covers skills such as reading emotions and understanding others’ intentions. This null finding held across all maltreatment subtypes, though researchers flag that the number of studies examining this domain remains limited and further investigation is needed.
Physical forms of maltreatment appeared to carry the greatest cognitive cost. This fits with a broader body of evidence suggesting that physical abuse and neglect in childhood are associated with more severe outcomes across mental health conditions. Among young people with bipolar disorder, physical abuse has also been linked to more intense mood symptoms and a greater likelihood of suicidal behaviour.
The biological mechanisms behind these associations are thought to involve disruption to normal brain development during childhood. Prolonged exposure to stress hormones, particularly cortisol, can impair the development of the prefrontal cortex and affect memory-related brain structures. These changes may compound existing vulnerabilities in people with bipolar disorder, worsening cognitive deficits that are already a known feature of the condition.
The researchers call for childhood trauma to be assessed routinely in clinical settings alongside cognitive functioning. They suggest that trauma-informed care, combined with cognitive remediation therapies, could help offset some of the long-term neuropsychological impact of early adversity.
Most of the included studies relied on retrospective self-reports and cross-sectional designs, which limits conclusions about causation. The researchers acknowledge that factors such as poverty, substance use, and illness duration may also play a role and were not consistently accounted for across studies.
The review underscores a growing consensus that early life experiences are not simply background context for mental illness. They shape the brain in ways that can affect how a person thinks, remembers, and functions for decades afterwards.
