Objective: This study was undertaken to investigate possible differenc
es in clinical, social and hospital prognosis in schizophrenics with o
r without codiagnosed alcoholism. Method: A representative sample was
selected by a two-stage random sample of sets from the total of 10,569
schizophrenic patients registered in the Croatian Psychotic Case Regi
ster in the period 1962-71. The resulting 449 schizophrenic patients w
ere psychiatrically examined in 1973-75 wherever they were found-at ho
me, in a hospital or in a social-health institution. Of these original
patients, 312 with or without a dual diagnosis of schizophrenia and a
lcoholism who were found at home were followed up until the final exam
ination in 1990-91. Results: Rate changes in 37 patients with the dual
diagnosis were significant in the following characteristics: they wer
e more often men, married, with a paranoid-hallucinatory disease form,
were aggressive during examination, and were without psychiatric afte
rcare or regular psychopharmacotherapy (p < .01); they came from rural
areas, had a mixed clinical picture with a deteriorating disease cour
se and were less communicative and socially functional, and were witho
ut work self-initiative and personal income (p < .05). Conclusions: Sc
hizophrenic patients found at home with codiagnosed alcoholism have po
orer clinical, hospital, social and life prognosis and need longer hos
pitalization. They represent a special subgroup of schizophrenics requ
iring special therapeutic approach and early identification, inasmuch
as their course of the disease has a tendency toward rapid deteriorati
on. Prevention of alcoholism and its adequate treatment have far reach
ing implications for the prognosis of schizophrenic illness.