Indirect Evidence for Effects of Suggestion in Suicide: a Critical Mass Hypothesis

The suicide rates of 33 nations with populations over 1 million in 1970 were compared with the suicide rates of those nations in 1980. It was hypothesized that the higher the suicide rate in 1970, the larger should be the increase from 1970-1980. Nations with higher suicide rates in 1970 showed larger absolute increases in suicide rates from 1970-1980. Since larger suicide rates appeared to genarate larger absolute increases in suicide rates, the author wondered when these rates might level off.