Table 1.

Inclusion and exclusion criteria

Inclusion criteria	Exclusion criteria
Cases
Age 18–64 years	Transient psychotic symptoms resulting from acute intoxication as defined by ICD-10
Currently resident in catchment area (primary residence)	Moderate or severe learning disability, as defined by ICD-10
Presence of ICD-10 psychotic disorder, including substance-induced psychoses	Clinically manifest organic cerebral disorder (eg, infections, parasitic, toxic, cerebrovascular, epilepsy and brain injury), as defined by ICD-10
Not treated with antipsychotic medication for more than one continuous month prior to the start of initial case identification
Controls
Age 18–64 years	Past or current ICD-10 psychotic disorder
Currently resident in catchment area (primary residence)	Moderate or severe learning disability, as defined by ICD-10
Same gender as index case	Clinically manifest organic cerebral disorder (eg, infections, parasitic, toxic, cerebrovascular, epilepsy and brain injury), as defined by ICD-10
Within 5 years of age of index case
Relatives
Age 18 and above	Insufficient contact with case to provide information on family burden or mental health
Relative or carer of a case who has consented to participate in the current study