• INCLUSION CRITERIA:
• Boys and girls
• Ages 9-17 years of age; 17 year-old participants who reach their 18th birthday while in the study will be allowed to continue and complete research and clinical care procedures under this protocol.
• Meet DSM-IV criteria for bipolar disorder.
• The child must have a primary caregiver who can accompany him or her on trips to NIMH, provide reliable history and information, and complete rating scales.
• Patients must have a psychiatrist who provides clinical care for their BPD.
• All youth accepted into the study must be able to complete self-rating forms and to cooperate with other study procedures.

• Previous treatment failure as defined by:

  1. Failure to respond to an adequate trial (adequate dose for at least two weeks) of a mood stabilizer (either lithium or divalproex) plus an adequate trial (sufficient dose for an adequate duration) of an atypical antipsychotic (such as risperidone, olanzapine, quetiapine, ziprasidone, or aripiprazole) or
  2. Failure to respond to an adequate trial (sufficient dose for an adequate duration) of two atypical antipsychotics (such as risperidone, olanzapine, quetiapine, ziprasidone, or aripiprazole) or
  3. Evidence of intolerance (severe weight gain or other side effects) of a mood stabilizer or atypical antipsychotic agent.

• The child is failing his/her current treatment as defined by (all 3 met):

  1. The child's current CGAS score must be less than 60.
  2. The child's current psychiatrist must agree that the child's response to his/her current treatment is no more than minimal or there are drug side effects that are proving problematic. According to this criterion, it would be clinically appropriate to change the child's current treatment.
  3. On the basis of record review and interviews with child and parent, the research team agrees that the child's response to his/her current treatment is no more than minimal.
• Subject has a PARS score of greater than or equal to 10, derived from the total of the following individual items: 3 (overall severity of anxious feelings), 5 (overall avoidance), 6 (interference with family), and 7 (interference outside of the home). In addition, patients must score 3 or higher (i.e., in the clinical range) on at least one of the four items noted above.

EXCLUSION CRITERIA:

• I.Q. less than 70
• Autistic disorder or severe pervasive developmental disorder; psychosis that interferes with the child's capacity to understand and comply with study procedures;
• Unstable medical illness (e.g. severe asthma) or contraindication to riluzole
• Medical illness that could cause the symptoms of bipolar illness (e.g. multiple sclerosis, thyroid disease);
• Pregnancy
• Renal or hepatic dysfunction that would interfere with excretion or metabolism of riluzole as evidenced by increase above upper limits of normal for BUN/creatinine, or two-fold elevation of serum transaminases (ALT/SGPT, AST/SGOT), gamma glutamate (GGT), or bilirubin.
• Documented history of hypersensitivity or intolerance to riluzole.
• Substance abuse within two months of study entry