Mental illness, especially depression, has consistently been regarded as the most important causal factor for suicide. In the 19th century about half the coroners’ verdicts on suicide were that the victims were 'insane'. Between 1900 and 1950 there was evidence of psychiatric illness among two in five women and more than one in six men who killed themselves. Sometimes depression among women was brought on by such events as menopause or childbirth (post-natal depression). Among men the effects of war were significant. Physically maimed and emotionally traumatised by the First World War, more than 600 returned soldiers killed themselves.
In the early 21st century researchers concluded that up to 70% of people dying by suicide or attempting it were suffering from mental disorders. People discharged after in-patient treatment for psychiatric illness were more likely to take their own lives and are in fact the group at highest risk of dying by suicide.
Recently it has been acknowledged that social factors are also key contributors to suicide rates, and that the causative role of extreme psychosocial distress (rather than mental illness) may have been downplayed in more traditional research.
Alcohol and drugs
Alcohol is a major factor in suicides among men. About one in eight male deaths by suicide between 1900 and 1950 were related to alcohol abuse. Often heavy drinking was associated with unemployment and marital troubles. A 1990s study of Christchurch young people who made serious suicide attempts found that 31% had symptoms of alcohol abuse and 12% of cannabis dependence.
The horror! The horror!
The worst effects of alcohol often came out during delirium tremens or ‘the horrors’, when people had paranoid delusions which might lead to suicidal acts. In 1874 Thomas Swann, a Kaiapoi workman, cut his throat with a razor while his mates were at work, because he thought the ‘devil was after him’. 1
Among youth suicides there is usually a combination of factors, such as a disrupted family background, mental illness, drug or alcohol abuse, and a recent relationship disruption.
When there were few available painkillers, escape from physical illness was a common reason for suicide. Until 1939 more than 40% of those over 60 who killed themselves in Auckland wanted to avoid continuing illness. Improvements in pain relief help explain the drop in older suicides since then.
Suicides caused by romantic situations had varied motives. Sometimes it was just heart-break. ‘Your words have severed every cord in my heart and I hope to have a long quiet rest’, wrote Anthony Paterson to his girlfriend before his suicide.2 Sometimes it was jealousy: ‘By the time you get this I will be gone forever and you will be free to carry on your intrigue with a married man’, one man wrote to his wife.3 Sometimes it was even more complicated – Pat Johns wrote, ‘I have found myself doing the most horrid things to hurt [his wife]...’4 To forestall a terrible deed, he took his own life.
Suicidal attempts were often triggered by life crises. Sometimes it was the death of a close relative; more often it was a breakdown in a romantic relationship. This was especially the case for younger people. Between 1900 and 1950 romantic rejection was the cause of almost one in five male suicides and one in three female suicides among those aged under 20.
There is also increasing evidence that people who are gay, lesbian, bisexual, transgender of intersexual have a greater risk of suicide. This is almost certainly related to stigma and discrimination which can occur anywhere, including within families.
The high rate of Māori youth suicide in the 21st century has been attributed to similar factors – mental illness, drug abuse and family disruption in the context of Māori social and economic deprivation. More recently it has been acknowledged that the effects of colonisation remain far-reaching and must be considered as a contributing factor.