Inclusion Criteria:

• Adolescent boys or girls aged 13 to 18 inclusive
• Weighing more than 40 kg
• Capable of understanding the protocol
• Who have given their written consent, as have their parents or legal guardian unless the adolescent has passed his/her 18th birthday
• Presenting the diagnostic characteristics of manic, mixed or hypomanic episodes of bipolar disorder established in accordance with the DSM IV, gathered in a semi-structured interview (Mini International Neuropsychiatric Interview - M.I.N.I.)
• With a score on the YMRS scale (Young Mania Rating Scale) >= 14 for the manic or mixed episode or >= 10 for the hypomanic episode
• Absence in blood of valproic acid at the inclusion visit
• Willing to use effective contraception in the case of girls of child-bearing potential. In this case the investigator should satisfy him/herself as to the psychological capacity of the patient to understand and undertake use of this contraception.
• Whose physiological test results are normal: hepatic function, blood count, lipid levels, fasting blood glucose level, blood urea, blood ammonia, blood protein, serum creatinine levels and plasma ions

Exclusion Criteria:

• General criteria:

  • Pregnant girls, or those breast-feeding or those for whom a pregnancy test is positive (blood beta HCG test)
  • Simultaneous participation in another study or in the 2 months preceding selection of the patient

• Psychiatric criteria:

  • Established or known mental retardation
  • Autistic disorders
  • Established schizophrenia
  • Schizoaffective disorders

• Somatic criteria:

  • Medical or organic disease of the CNS (epilepsy, tumour etc.)
  • Any known renal, cardiac or haematological disease, or disease of the immune system
  • Endocrine disorders and/or any biochemical abnormality known or existing at the moment of inclusion

• Exclusion criteria linked to the treatment

  • Known hypersensitivity to valproate or to sodium divalproate or to one of the constituents of the drug
  • Hepatic disease: acute hepatitis, chronic hepatitis, past personal or family history of severe hepatitis particularly caused by medicinal products, hepatic porphyria
  • Treatment with lamotrigine, (Lamictal)
  • Treatment with mefloquine, (Lariam)
  • Any treatment based on valproate
  • Treatment with methylphenidate (Ritalin)

The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.