It is well established that psychosis may arise in the context of the abuse of certain prescribed or illicit drugs. Two cases of paranoid psychosis are described in which proprietary preparations containing amphetamine-like drugs were abused. The role of these drugs is discussed with reference to previous case reports, and it is emphasised that initial clinical assessment and urinary screening for drugs may fail to reveal the relevant history with respect to proprietary medicines.

Two cases of catatonic stupor are described due to presumed encephalitis lethargica. Catatonic and obsessional phenomena in the setting of a depressive psychosis associated with a movement disorder may constitute a post-encephalitic syndrome.

Mentally handicapped people are increasingly being subjected to the stresses of everyday life, and bereavement represents a particularly potent stress. This report considers the case of a mentally handicapped woman whose difficulty in mourning and expressing and sharing grief had a profound effect on her recovery from bereavement and led to her developing an affective psychosis.

Diagnosis of classic psychiatric illness in mentally handicapped individuals remains difficult. Manic-depressive illness has previously been reported in both pre-pubertal and pubertal children with a mental handicap and with a family history. This paper reports a case of manic-depressive psychosis in childhood, with no family history, short-cycle mood swings and good response to lithium therapy.

A patient presenting with mixed affective symptoms was found to have active neurosyphilis after intermittent cognitive impairment suggested an organic cause. Most of these symptoms resolved after treatment with penicillin.