OBJECTIVE: To determine whether dietary supplementation or psychosocial stimulation given to growth retarded (stunted) children age 9-24 months has long term benefits for their psychosocial functioning in late adolescence.

DESIGN:Sixteen year follow-up study of a randomised controlled trial.

SETTING: Poor neighbourhoods in Kingston, Jamaica.

PARTICIPANTS: Of 129 stunted children identified at age 9-24 months, 103 adolescents aged 17-18 were followed up.

INTERVENTION: Supplementation with 1 kg milk based formula each week or psychosocial stimulation (weekly play sessions with mother and child), or both, for two years.

MAIN OUTCOME MEASURES: Anxiety, depression, self esteem, and antisocial behaviour assessed by questionnaires administered by interviewers; attention deficit, hyperactivity, and oppositional behaviour assessed by interviews with parents.

RESULTS: Primary analysis indicated that participants who received stimulation had significantly different overall scores from those who did not (F = 2.047, P = 0.049). Supplementation had no significant effect (F = 1.505, P = 0.17). Participants who received stimulation reported less anxiety (mean difference – 2.81, 95% confidence interval – 5.02 to – 0.61), less depression (- 0.43, – 0.78 to – 0.07), and higher self esteem (1.55, 0.08 to 3.02) and parents reported fewer attention problems (- 3.34, – 6.48 to – 0.19). These differences are equivalent to effect sizes of 0.40-0.49 standard deviations.

CONCLUSIONS: Stimulation in early childhood has sustained benefits to stunted children’s emotional outcomes and attention.