Childhood abuse, family history and stressors in older patients with bipolar disorder in relation to age at onset

•About 25.6% of the older bipolar patients experienced verbal, physical or sexual abuse in childhood and childhood abuse was not related to a family history of psychiatric disorders.•In older bipolar patients 76.9% had one or more first degree relative with a psychiatric disorder.•Depression was the most common disorder in both first degree relatives and second degree relatives.•Family history of psychiatric disorders was the only significant predictor of an early age at onset.•Negative stressors may play a specific role in first late life mania.