Regarding the primary outcome of psychological and learning capabilities , both studies assessed the effect of interventions on  children 's verbal and non-verbal intellectual functioning using the Wechsler Intelligence Scale for Children - Revised .
AUTHORS ' CONCLUSIONS Low- quality evidence from two small trials showed that when compared to placebo , LAC may not improve intellectual functioning or hyperactive behaviour in children with FXS
BACKGROUND People with fragile X syndrome ( FXS ) have an intellectual dysfunction that can range from very mild to severe .
Symptoms can include speech and language delays and behavioural difficulties such as aggression or self injurious behaviours , emotional lability , and anxiety-related problems ( for example obsessive-compulsive symptoms and perseverative behaviours ) .
In some cases , affected people may have an additional diagnosis of attention deficit hyperactivity disorder or an autism spectrum disorder .
OBJECTIVES To review the efficacy and safety of L-acetylcarnitine in improving the psychological , intellectual , and social performance of people with FXS .
Efficacy of carnitine in the treatment of children with attention-deficit hyperactivity disorder.
To determine safety and the efficacy of carnitine treatment in children with attention-deficit hyperactivity disorder ( ADHD ) . The ADHD behavior was observed by parents completing the Child Behavior Checklist ( CBCL ) and by teachers completing the  Conners teacher-rating score  , in a r and omized , double-blind , placebo-controlled double-crossover trial . In 13/24 boys receiving carnitine  , home behavior improved as assessed with the CBCL total score ( P < 0.02 ) . In 13/24 boys , school behavior improved as assessed with the Conners teacher-rating score ( P < 0.05 ) . Before treatment , the CBCL total and sub-scores were significantly different from those of normal Dutch boys ( P < 0.0001 ) . Responders showed a significant improvement of the CBCL total scores compared to baseline ( P < 0.0001 ) . In the majority of boys no side effects were seen . At baseline and after carnitine treatment , responders showed higher levels of plasma-free carnitine ( P < 0.03 ) and acetylcarnitine ( P < 0.05 ) . Compared to baseline , the carnitine treatment caused in the responsive patients a decrease of 20 - 65 % ( 8 - 48 points ) as assessed by the CBCL total problem rating scale . Treatment with carnitine significantly decreased the attention problems and aggressive behavior in boys with ADHD
Regarding the primary outcome of psychological and learning capabilities , both studies assessed the effect of interventions on  children 's verbal and non-verbal intellectual functioning using the Wechsler Intelligence Scale for Children - Revised .
AUTHORS ' CONCLUSIONS Low- quality evidence from two small trials showed that when compared to placebo , LAC may not improve intellectual functioning or hyperactive behaviour in children with FXS
BACKGROUND People with fragile X syndrome ( FXS ) have an intellectual dysfunction that can range from very mild to severe .
Symptoms can include speech and language delays and behavioural difficulties such as aggression or self injurious behaviours , emotional lability , and anxiety-related problems ( for example obsessive-compulsive symptoms and perseverative behaviours ) .
In some cases , affected people may have an additional diagnosis of attention deficit hyperactivity disorder or an autism spectrum disorder .
OBJECTIVES To review the efficacy and safety of L-acetylcarnitine in improving the psychological , intellectual , and social performance of people with FXS .