Can You Predict Mental Capacity in Adulthood When Assessing a Child?

Can You Predict Mental Capacity in Adulthood When Assessing a Child?

Assessing mental capacity in children presents significant challenges, particularly when trying to determine their future decision-making abilities. While adults are assessed under the Mental Capacity Act 2005 (MCA), children under 16 are evaluated using Gillick competence, which considers their maturity and understanding at the time of decision-making.

However, in medico-legal settings, professionals are sometimes asked to predict whether a child will have capacity in adulthood—especially in cases involving financial settlements, future medical consent, or legal responsibility. This raises critical ethical, legal, and clinical concerns, as mental capacity is decision-specific and time-dependent, making long-term predictions inherently unreliable.

This article explores the complexities of predicting future capacity, the factors influencing cognitive development, and the best practices for assessing and supporting children with potential capacity challenges.

The Legal Landscape: Why Future Capacity Predictions Are Problematic

Under UK law, mental capacity assessments must follow two key principles:

1. Capacity is assessed in the present – A person’s ability to make decisions must be evaluated at the time the decision arises.
2. Capacity is decision-specific – A person may have capacity for some decisions but not others.

Since the Mental Capacity Act (MCA) 2005 only applies from age 16, courts and medico-legal professionals cannot definitively assess a child’s future capacity. Instead, decision-making ability must be reviewed when adulthood is reached.

Misuse of Mental Capacity Assessments in Legal Cases

Predicting financial capacity: In personal injury cases, solicitors may request an expert to determine whether a child will be capable of managing compensation funds when they reach adulthood. However, because financial decision-making requires a complex interplay of cognitive skills, predicting capacity in 10–15 years is unreliable.

Forecasting legal responsibility: Family law cases may involve assessing whether a child will have capacity for independent decision-making in adulthood. However, psychological and environmental factors can significantly alter development

Long-term medical consent: A child may lack capacity for serious medical decisions at a young age but develop it as they mature. Fixed predictions risk restricting their future autonomy.

The Science of Development: What Influences Future Capacity?

Predicting a child’s future mental capacity is complicated by several variables, including:

Neurodevelopment and Brain Maturation

• Cognitive abilities evolve significantly throughout childhood and adolescence.
• Executive functions (planning, reasoning, impulse control) continue developing until the mid-20s.
• Injuries, neurodevelopmental conditions (e.g., autism, ADHD, learning disabilities) or mental health disorders may influence capacity later in life.

Environmental and Educational Factors

• Early access to therapy, special education, or interventions can enhance cognitive and emotional resilience.
• Socioeconomic status, family stability, and access to support networks play a crucial role in decision-making ability.

Mental Health and Emotional Regulation

• Conditions like depression, anxiety, PTSD, or emerging psychiatric disorders can fluctuate over time, affecting decision-making abilities.
• Emotional maturity is a significant factor in understanding risks and consequences in adulthood.

The Ethical and Clinical Risks of Long-Term Capacity Predictions

 Inaccuracy and Unreliability

Cognitive development is not linear and can be influenced by medical, psychological, and social changes. Declaring a child as incapable for life based on a premature assessment risks misrepresentation.

Risk of Limiting Future Autonomy

Labelling a child as lacking future capacity may restrict their ability to make independent decisions as an adult. Some individuals may develop stronger decision-making skills later in life than originally anticipated.

Legal and Ethical Implications

Gillick competence and the MCA 2005 require assessments at the point of decision-making, not years in advance. Fixed predictions could lead to inappropriate legal restrictions on financial, medical, or personal decisions.

Best Practices: How to Approach Mental Capacity Assessments in Children

Assess Current Decision-Making Abilities, Not Future Capacity

• Use Gillick competence for children under 16.
• Ensure assessments only evaluate the child’s current ability to understand and weigh decisions.

Acknowledge Capacity as a Developmental Process

• Capacity can change over time; reassessment is essential as the child matures.
• Document factors that might influence future decision-making but avoid fixed conclusions.

Involve Multidisciplinary Teams (MDTs) for Comprehensive Evaluations

• Neuropsychologists assess cognitive function and executive skills.
• Speech and language therapists evaluate communication and comprehension.
• Occupational therapists help assess independent living skills.
• Legal professionals ensure that findings align with medico-legal standards.

Use a Balanced Approach in Medico-Legal Reports

• Avoid definitive statements about future capacity.
• Instead, highlight areas of concern, need for reassessment, and potential influencing factors.

The ability to predict a child’s future mental capacity is limited by biological, psychological, and environmental factors. While medico-legal cases may sometimes seek long-term capacity assessments, professionals must approach such requests with caution, integrity, and adherence to legal framework.

At The London Neurocognitive Clinic our clinicians always assess capacity at the time of decision-making. We cannot predict future capacity as it is unreliable and risks restricting autonomy. Instead, we use a multidisciplinary approach to ensure a balanced, developmentally appropriate assessment of present capabilities with recommendations about future assessment needs.