Suicidal ideation and the 'wish to die' in dementia patients: the role of depression.

OBJECTIVE: To determine the prevalence of self-reported suicidal ideation and the 'wish to die' in dementia patients, their association with depressive symptoms and the type of dementia.

DESIGN: The cohort was formed retrospectively of consecutive referrals between 1985 and 1994 of cognitively impaired patients who met American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders, third edition and third edition, revised, criteria for dementia. They were assessed for depression using the 21-item Hamilton Rating Scale for Depression (HRSD) which includes an item on suicide.

SETTING: An outpatient multidisciplinary memory disorders clinic in Sydney, Australia.

PATIENTS: The sample comprised 221 patients with dementia: 148 with Alzheimer's disease according to NINCDS-ADRDA criteria, 24 with vascular dementia diagnosed by a Hachinski ischaemia scale score of seven or more, plus focal neurological signs, symptoms or computed tomography-visible lesions, and 49 with other dementias.

MEASURES: Cognitive impairment was measured by the Mini-Mental State Examination and the Blessed orientation-information-memory-concentration test and dementia scales, depression by the 21-item HRSD, suicidal ideation and the 'wish to die' as defined by the suicide item on the HRSD, functional capacity by the activities of daily living scale and the instrumental activities of daily living scale. Caregiver psychological morbidity was assessed with the General Health Questionnaire.

RESULTS: 12 patients (5.4%) felt life was not worth living, seven (3.2%) 'wished to die' or had thoughts of death, two (0.9%) had suicidal ideation or gestures and none had made any suicide attempts. The nine patients who 'wished to die' or had suicidal ideation scored 12 or more on the HRSD. Of these, six were clinically depressed. Suicidal ideation and the 'wish to die' were significantly correlated with the presence of depressive symptoms as measured by the HRSD (suicide item excluded), but only in those with Alzheimer's disease. There were no significant differences in HRSD scores between the dementia groups. Suicidal ideation was unrelated to the presence of insight into loss of memory.

CONCLUSIONS: Suicidal ideation and/or the 'wish to die' is self-reported in 4% of dementia patients attending a memory disorders clinic and is associated with comorbid depressive symptoms, particularly in Alzheimer's disease.