Antipsychotics in young people and the metabolic risk
Second-generation antipsychotics are increasingly prescribed to children and adolescents. Their effects on weight and metabolism appear to be greater than in adults.
In brief
Second-generation antipsychotics cause more weight gain in children and adolescents than in adults. The metabolic risks, monitoring and management.
Second-generation antipsychotics are used in children and adolescents for conditions including schizophrenia, bipolar disorder and severe irritability associated with autism. Prescribing to young people has risen, including off-label use for behavioural problems.
A bigger effect in the young
Weight gain is a known side effect of these medicines in adults. Studies in young people who had not taken antipsychotics before found that weight gain could be rapid and substantial within weeks of starting treatment, alongside changes in blood lipids and markers of insulin resistance. Young people appear to be more susceptible than adults.
The risk varies between drugs. Some are associated with considerably more weight gain than others, which makes the choice of agent itself a safety decision.
Why it matters long-term
Weight gain and metabolic changes in adolescence can set a trajectory towards obesity, type 2 diabetes and cardiovascular disease in adulthood. They also affect adherence: young people who gain weight are more likely to stop treatment, risking relapse of the underlying condition.
Monitoring
Clinical guidelines recommend measuring weight, height, body mass index, waist circumference, blood pressure, fasting glucose and lipids before starting treatment, then repeating them at regular intervals. Audits have repeatedly found that monitoring in practice falls short of these recommendations.
Managing the risk
Options include choosing agents with lower metabolic risk, using the lowest effective dose, combining treatment with lifestyle support and, in some cases, adding metformin, which has been studied for attenuating antipsychotic-associated weight gain in young people. Regulators and guideline bodies also emphasise reviewing whether the medicine is still needed, particularly where it was started for behavioural symptoms rather than psychosis.
