Quetiapine (Seroquel) Maintenance Treatment in Early Onset Bipolar Spectrum Disorders

Inclusion criteria

• Provide written informed consent before initiation of any study-related procedures.
• A lifetime diagnosis of bipolar spectrum disorder: bipolar I and bipolar II disorders, cyclothymia, bipolar NOS, as defined by the Diagnostic and Statistical Manual of Mental Disorders - Fourth Edition (DSM-IV).
• Male or female, between the ages of 12 and 20 years at enrolment.
• No preventive treatment at least one month prior to enrolment.
• Female patients of childbearing potential and who are sexually active must be using a reliable method of contraception. Reliable methods of contraception include hormonal contraceptives (e.g., oral contraceptive or long-term injectable or implantable hormonal contraceptive), double-barrier methods (e.g., condom and diaphragm, condom and foam, condom and sponge), intrauterine devices, and tubal ligation.
• Able to understand and comply with the requirements of the study.

Exclusion criteria

• Known intolerance or lack of response to quetiapine fumarate as judged by the investigator.
• Pregnancy or lactation. Female patients of childbearing potential must have a negative urine human chorionic gonadotropin (HCG) test at enrolment.
• History of substance or alcohol dependence within three months of enrolment (except for caffeine or nicotine dependence), as defined by DSM-IV criteria.
• Opiates, amphetamine, barbiturate, cocaine, cannabis, or hallucinogen abuse by DSM-IV criteria within 4 weeks prior to enrolment.
• Use of any of the following cytochrome P450 3A4 inhibitors in the 14 days preceding enrolment including but not limited to: ketoconazole, itraconazole, fluconazole, erythromycin, clarithromycin, troleandomycin, indinavir, nelfinavir, ritonavir, and saquinavir. Should a new drug be started, investigators will consult the pharmacy as this list is not exhaustive.
• Use of any of the following cytochrome P450 inducers in the 14 days preceding enrolment including but not limited to: phenytoin, carbamazepine, barbiturates, rifampin, St. John's Wort, and glucocorticoids.
• Current use of fluvoxamine, nefazodone, or grapefruit juice.
• Thyroid stimulating hormone (TSH) concentration outside of the normal range.
• Unstable or inadequately treated medical illness (e.g., diabetes, angina pectoris, hypertension) as judged by the investigator.
• History of hepatic disease, or elevated hepatic enzymes at entry testing.
• Medical conditions that would affect absorption, distribution, metabolism, or excretion of study treatment.
• Use of an experimental drug within 30 days of enrolment.
• Previous trials of maintenance therapy.