"It is worrying that, rather than showing signs of dropping or even levelling off, late-life suicide may in fact be on the increase," said the group's chief executive officer Zane Wilson."
She said the fears of mental health professionals seemed justified against the backdrop of similar concerns in other countries, as the world observes World Suicide Prevention Day on Friday.
"Where suicide among teenagers and young adults, whose futures still lie before them, is a tragic enough phenomenon that galvanises public outrage, late-life suicide is often accepted with greater social ease."
Wilson said her group had been working hard on suicide prevention campaigns and research into suicide among the young, especially in rural areas where poverty and HIV/Aids were having a devastating impact.
"However, we cannot afford to lose sight of the cruel fact that elderly people are still killing themselves, even if the causes may be completely different from those driving younger generations to kill themselves."
Citing work by Dr Gary Kennedy of New York's Albert Einstein College of Medicine, Wilson said suicide was "a major public health problem that is still not sufficiently addressed either in the research arena, by government or in clinical practice".
She said the psychologists had believed for over a century that isolation and other social factors were major contributors to suicide later in life.
"Recent research has again supported this view, but it also depends on local stressors as well as community relations."
Wilson said in the United State suicide was sometimes portrayed by the media as "an escape from intolerable circumstances", especially where disease and pain were associated.
She said this perception might also influence others to view suicide as an acceptable means of solving a problem, both in the patient and the family.
"Research suggests that more women in South Africa attempt suicide, although men show a higher fatality or 'success' rate.
" This is probably attributable in large part to the means chosen - someone who has taken an overdose is more likely to be found before it is too late.
"Clearly, more research into the causes for late-life suicide is needed."
Meanwhile, society should not close its eyes to this phenomenon - especially where professionals and lay people could help restore balance and give older people the same hope that sustained them earlier in their lives, said Wilson.