Tolerance and Effect of Antipsychotics in Children and Adolescents With Psychosis

Patients - Inclusion Criteria: * Diagnosis: Children and adolescents with a non-organic and non-drug-induced psychosis, meeting the criteria for ICD-10 diagnoses: F20, F22-F29 and F30.2, F31.2 F31.5, F32.3 and F33.3. This is verified with a semi-structured psychopathological interview using K-SADS-PL (Kaufmann 1997) four weeks after inclusion into the trial. * Psychopathology: Children and adolescents with psychotic symptoms, scoring ≥ 4 on at least one of the following PANSS items: P1 (delusions), P2 (conceptual disorganisation), P3 (hallucinations), P5 (grandiosity), P6 (suspiciousness/persecution) or G9 (unusual thought content); and a total PANSS score \> 60. The treating physician has decided to prescribe an antipsychotic compound. * Age: 12-17 years (both inclusive). * Sex: Both sexes are included. * Previous treatment: Patients must be antipsychotic-naïve. The maximum accepted previous treatment with antipsychotic compounds is two weeks cumulatively, and during the two weeks prior to inclusion no continuous treatment and a maximum of four dosages in total can have been received. * Somatic illness: No somatic contraindication to planned medication, documented by standard somatic examination * Written informed consent. Patients - Exclusion Criteria: * Compulsory treatment: Patients that are compulsorily hospitalised against their will are excluded. If their status changes to voluntary hospitalisation, patients can be included. If the patient is already included in the trial and is briefly detained, confined, or subjected to other forceful treatment according to the Danish Psychiatric Care Act ('Psykiatriloven'), both the patient and parents have to agree to remain in the trial if exclusion is to be avoided. Compulsory treatment in the form of, e.g., brief forced immobilisation or single instances of forced medication, are not causes for exclusion. * Diagnoses: Patients with drug-induced or organic psychosis, severe chronic somatic illness, or a history of severe head-trauma are not included. Patients that do not have psychotic symptoms but are prescribed antipsychotic treatment on the indication of, e.g., severe behavioural problems or tics are not included. * Pregnancy: Pregnant or lactating patients are not included (a pregnancy test is undertaken at inclusion). Female participants, that are sexually active, must use safe contraception throughout the trial period (see section 6.4) * Substance abuse: People with severe alcohol or drug abuse are not included. Possible abuse is monitored both by interviewing participants and by taking a urine sample at inclusion and at 4, 12 and 52 weeks follow-up (if there is suspicion of substance abuse), testing for the presence of cocaine, amphetamine, cannabis, opiates, metamfetamine (inclusive for extacy), and benzodiazepines. When severe abuse is suspected during the trial, an ad hoc urine sample is taken. Brief periods of large alcohol/cannabis intake are not a cause of exclusion from the trial; however, cognitive and other examinations are not carried out while patients are under the influence of drugs or alcohol. * Aggravation: Patients may be excluded if there is a significant worsening of clinical state during the course of the trial (i.e., increases of 30% or more from baseline on the PANSS total score). * Allergy and intolerance: Patients with allergy towards the investigational drugs, or is lactose intolerant are not included. * Lack of informed consent. Healthy volunteers - Inclusion Criteria: * Matching: Healthy controls (n=100) are included, in the way that they are matched to the first 100 patients included in the study (i.e., corresponding to the number of patients required in each treatment group). They will be matched according to: * age; * sex; and * socioeconomic status (based on a combination of parental education and income, according to criteria from the National Institute of Public Health (earlier Danish Institute of Clinical Epidemiology, DIKE)). * Informed consent. Healthy volunteers - Exclusion Criteria: * Psychopathology: People with a previous psychotic disorder (ICD 10, F20-F29 and F30.2, F31.2, F31.5, F32.3 and F33.3) or current psychiatric disorder (multiaxial axis 1) are not included. This is verified by diagnostic screening using K-SADS-PL at eligibility assessment before inclusion into the study of healthy controls. The presence of psychotic psychiatric diagnoses in first-degree relatives is also a cause for exclusion. * Somatic illnesses: People with severe chronic somatic illness or a history of severe head-trauma are not included. * Intelligence: People with known mild mental retardation (i.e., IQ between 50-70) prior to inclusion are excluded; however, if mild mental retardation is found during the study, participants are not excluded, since they must be considered a marginal part of the normal distribution. People with moderate to severe mental retardation (i.e., IQ \< 50) are excluded. * Substance abuse: People with severe alcohol- or drug abuse are excluded. Possible abuse is monitored both by interviewing participants and by taking a urine sample at inclusion and at 4, 12 and 52 weeks follow-up (if there is suspicion of substance abuse), testing for the presence of cocaine, amphetamine, cannabis, opiates, metamfetamine (inclusive for extacy) and benzodiazepines. Brief periods of large alcohol/cannabis intake are not a cause of exclusion from the study; however, cognitive and other examinations are not carried out while participants are under the influence. * Lack of informed consent.