Analgesic nephropathy is more common in Western Scotland than elsewhere in the United Kingdom. This appears to be a consequence of the frequency with which local people take Askit, a preparation different from most other British analgesics in that they contain more caffeine and in their presentation as powders. Surveys of different populations in Glasgow suggest that while aspirin and paracetamol tend to be taken relatively infrequently and for appropriate reasons such as pain, Askit is more likely to be taken with excessive frequency for its supposed mood-altering properties. Working-class women with psychiatric problems are especially prone to daily self-medication. Study of individuals with analgesic nephropathy reveals that in Western Scotland, at least, the cause is dependence on analgesics. The characteristics of this include a need to continue taking and to slowly increase the dose of analgesics, partly owing to tolerance and partly to treat symptoms the analgesic ingestion has caused, as well as a psychic dependence resulting from appreciation of the psychotropic effects of the compound analgesics. When compared with matched controls, those who develop the "analgesic abuse syndrome" are more likely to have a family history of analgesic abuse, alcoholism, and psychiatric disorder. They tend to be introverted and neurotic, are prone to abuse other drugs and many have had previous psychiatric treatment.