Taurine trial in succinic semialdehyde dehydrogenase deficiency and elevated CNS GABA.

OBJECTIVES: The objective of this open-label study was primarily to assess the effect of taurine on adaptive behavior and secondarily to collect safety and tolerability data in patients with succinic semialdehyde dehydrogenase deficiency. METHODS: In the current study, subjects were titrated weekly from a starting dose of 50 mg/kg/d to a target 200 mg/kg/d, and assessed for safety, tolerability, and adaptive functioning using age-normalized Adaptive Behavior Assessment Scales. RESULTS: Eighteen patients (8 males/10 females, aged 0.5-28 years, mean 12 years) were recruited. Three subjects withdrew because of perceived lack of efficacy. One serious adverse event occurred (hospitalization for hypersomnia) on 16 g/d (200 mg/kg/d), leading to a dose-lowering paradigm with a maximum dose of 10 g/d. Results did not show clinically meaningful improvement in the adaptive domains after taurine therapy. Pre- and posttherapy adaptive scores also demonstrated no statistically significant difference (p > 0.18). CONCLUSIONS: Adaptive behavior did not improve significantly with taurine intervention. Further therapeutic clinical trials including an on-off paradigm using biomarkers are planned. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that for patients with succinic semialdehyde dehydrogenase deficiency, taurine does not significantly improve adaptive behavior. The study is rated Class IV because of the absence of a control group.

Mother and child interpretations of threat in ambiguous situations: relations with child anxiety and autonomic responding.

This study examined maternal and child interpretive bias to threat (IBT) during dyadic conversation, child physiological reactivity and regulation during dyadic conversation, and maternal report of child anxiety in a community sample of 35 mothers and their 8- to 10-year-old children. Mothers and children discussed one neutral and six ambiguous scenarios, which were subsequently coded for frequency of maternal and child initiation, minimization, and expansion of threat-related themes. Child electrocardiogram data were collected during these conversations and maternal reports of child anxiety and internalizing problems were obtained. Across the sample, children initiated threat-related discussion more often than mothers. Maternal threat expansions were significantly positively correlated with child anxiety and internalizing behaviors. Maternal minimizations of threat were significantly associated with augmented child vagal tone throughout the IBT paradigm. Implications for prevention of child anxiety and directions for extending IBT research within the context of the mother-child dyad are discussed.