History of depression prior to Alzheimer's disease and vascular dementia verified post-mortem

The aim of this study was to analyze the medical history, with regards to previous remote depression, in patients with neuropathologically verified Alzheimer's disease (AD), vascular dementia (VaD) and mixed AD/VaD. The 201 patients included (115 AD, 44 VaD and 42 mixed AD/VaD) had been referred to the Psychogeriatric/Psychiatric Department, Lund University Hospital, for psychogeriatric investigation and were followed-up with clinical records and detailed information on psychiatric history prior to the onset of dementia. Depression was considered to exist when the patient had consulted a psychiatrist or physician and had been diagnosed with a “depressive episode” or “depression” and when anti-depressants and/or other specific treatments had been prescribed. Twenty patients (10%) had suffered from depression earlier in life well before the onset of dementia. Eight of the 9 AD patients with a previous diagnosis of depression had suffered from only one depressive episode and all had responded well to treatment, with complete recovery. In the VaD group, 8 out of 9 patients suffered two or more depressive episodes and only two recovered completely. Events with a possible significant relationship to depression were seen in 8 of the 9 AD patients but in only 1 of the 9 VaD patients. Psychotic symptoms were more common in VaD than in the AD group. The treatment modality of depression was similar in the groups. In conclusion, a history of depression prior to dementia is more common and more therapy-resistant in VaD than in AD.