Twenty-five male subjects suffering from senile psychosis were treated by six intramuscular injections of vitamin preparation “Parentrovite” controlled by twenty-five similar cases receiving an inactive preparation or placebo. The two groups were found to be well matched in terms of age and memory.

The encouraging results from the experimental group treated with “Parentrovite” suggest that further trials of the preparation should be undertaken. This group showed significantly greater increases on successive retestings with the Wechsler Memory Scale than the control group. Behavioural improvement occurred more often in the experimental than in the control group.

Although the total increases in the control group treated with the inert preparation were significantly less than those in the experimental group nevertheless, some improvement in memory and behaviour resulted. It would appear to point to the danger that psychiatric symptoms may too easily be assumed to result from totally irreversible organic processes in the senile patient rather than consider that some, at least, of these may be of reversible causation.