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 .
Acetyl-L-carnitine (ALC) in attention-deficit/hyperactivity disorder: a multi-site, placebo-controlled pilot trial.
OBJECTIVE To determine whether acetyl-L-carnitine ( ALC ) , a metabolite necessary for energy metabolism and essential fatty acid anabolism , might help attention-deficit/hyperactivity disorder ( ADHD ) . Trials in Down 's syndrome , migraine , and Alzheimer 's disease showed benefit for attention . A preliminary trial in ADHD using L-carnitine reported significant benefit . METHOD A multi-site 16-week pilot study r and omized 112 children ( 83 boys , 29 girls ) age 5 - 12 with systematic ally diagnosed ADHD to placebo or ALC in weight-based doses from 500 to 1500 mg b.i.d . The 2001 revisions of the Conners ' parent and teacher scales ( including DSM-IV ADHD symptoms ) were administered at baseline , 8 , 12 , and 16 weeks . Analyses were ANOVA of change from baseline to 16 weeks with treatment , center , and treatment-by-center interaction as independent variables . RESULTS The primary intent-to-treat analysis , of 9 DSM-IV teacher-rated inattentive symptoms , was not significant . However , secondary analyses were interesting . There was significant ( p = 0.02 ) moderation by subtype : superiority of ALC over placebo in the inattentive type , with an opposite tendency in combined type . There was also a geographic effect ( p = 0.047 ) . Side effects were negligible ; electrocardiograms , lab work , and physical exam unremarkable . CONCLUSION ALC appears safe , but with no effect on the overall ADHD population ( especially combined type ) . It deserves further exploration for possible benefit specifically in the inattentive type
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 .