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passages: document
passages: Effects of tryptophan depletion in drug-free adults with autistic disorder . BACKGROUND The primary objective of this study was to investigate the behavioral and biochemical responses to acute tryptophan depletion in drug-free adult patients with autistic disorder . METHODS Twenty drug-free adults with autistic disorder ( 16 men and 4 women ) ( mean [ +/- SD ] age , 30.5 +/- 8.5 years ) underwent short-term tryptophan depletion in a double-blind , placebo-controlled , randomized crossover design . Patients received a 24-hour , low-tryptophan diet followed the next morning by an amino acid drink . Behavioral ratings were obtained on the morning of the amino acid drink ( baseline ) and 180 , 300 , and 420 minutes after the drink . Plasma free and total tryptophan levels were obtained at baseline and 5 hours after the drink . The active and sham testing sessions were separated by 7 days . RESULTS Eleven ( 65 % ) of the 17 patients who completed both test days showed a significant global worsening of behavioral symptoms with short-term tryptophan depletion , but none of the 17 patients showed any significant change in clinical status from baseline after sham depletion ( P = .001 ) . Tryptophan depletion led to a significant increase in behaviors such as whirling , flapping , pacing , banging and hitting self , rocking , and toe walking ( P < .05 ) . In addition , patients were significantly less calm and happy and more anxious . No significant change was observed in social relatedness or repetitive thoughts and behavior . Plasma total and free tryptophan levels were reduced 86 % and 69 % , respectively , 5 hours after the tryptophan-deficient amino acid drink . Patients who had a significant global exacerbation of symptoms had significantly higher baseline plasma total tryptophan levels ( P < .001 ) and Autism Behavior Checklist scores ( P = .005 ) than did patients who showed no significant change in symptoms after tryptophan depletion . CONCLUSIONS The results of this study are consistent with previous research that has implicated a dysregulation in serotonin function in some patients with autism . These data suggest that the short-term reduction of serotonin precursor availability may exacerbate some symptoms characteristic of autism in some patients . Continued investigation into the role of serotonin in the pathogenesis and treatment of autistic disorder is warranted .
entities: 3886
entities: Intervention_Pharmacological
entities: tryptophan depletion
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entities: Intervention_Pharmacological
entities: low-tryptophan diet
entities: 3888
entities: Intervention_Pharmacological
entities: amino acid drink .
entities: 3889
entities: Intervention_Pharmacological
entities: amino acid drink
entities: 3890
entities: Outcome_Physical
entities: Plasma free and total tryptophan levels
entities: 3891
entities: Outcome_Mental
entities: whirling , flapping , pacing , banging and hitting self , rocking , and toe walking
entities: 3892
entities: Outcome_Mental
entities: calm and happy
entities: 3893
entities: Outcome_Mental
entities: anxious .
entities: 3894
entities: Outcome_Mental
entities: social relatedness or repetitive thoughts and behavior .
entities: 3895
entities: Outcome_Physical
entities: Plasma total and free tryptophan levels
entities: 3896
entities: Outcome_Physical
entities: plasma total tryptophan levels
entities: 3897
entities: Outcome_Mental
entities: Autism Behavior Checklist scores
entities: 3898
entities: Outcome_Mental
entities: symptoms
entities: 3899
entities: Participant_Condition
entities: drug-free
entities: 3900
entities: Participant_Age
entities: adults
entities: 3901
entities: Participant_Condition
entities: autistic disorder
entities: 3902
entities: Participant_Condition
entities: drug-free adult patients with autistic disorder .
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entities: Participant_Sample-size
entities: Twenty
entities: 3904
entities: Participant_Condition
entities: drug-free adults with autistic disorder
entities: 3905
entities: Participant_Sample-size
entities: 16 men and 4 women
entities: 3906
entities: Participant_Age
entities: mean [ +/- SD ] age , 30.5 +/- 8.5 years
entities: 3907
entities: Participant_Condition
entities: patients with autism .