The 17th ACM SIGPLAN International Conference on Functional Programming (ICFP) took place on September 10–12, 2012 in Copenhagen, Denmark. After the conference, the programme committee selected several outstanding papers and invited their authors to submit to this special issue of Journal of Functional Programming. Robby Findler and Satnam Singh acted as editors for these submissions. This issue includes the accepted papers, each of which provides substantial new material beyond the original conference version.

Compulsive water drinking is associated with a broad spectrum of psychopathology, from mild neurosis to psychosis. Since the normal kidney is capable of excreting large volumes of fluid rapidly, water intoxication requires both a pathological basis and a psychiatric explanation of why so much water is being taken. Excessive water consumption can be dangerous, so that the fluid intake of patients with a history of polyuria together with a low urinary specific gravity should be closely observed. Four cases of water intoxication resulting from psychogenic polydipsia are described, three of them in chronic schizophrenics, where inappropriate ADH secretion might represent part of the psychosis.