In my transcriptions of wills from St. Augustine, Florida, between 1783 and 1821, I have encountered one that is quite sad. The individual in question was an Irishman living in Spanish St. Augustine (of which there were quite a few) in 1810, who had apparently been depressed or, as the investigatory documents state, "disaffected with life," having indicated as much to several of his friends the day before he took an overdose of two ounces of laudanum -- four times the amount needed for a fatal dose.
Was this suicide or an accidental overdose? Indications are that it was suicide. The above-mentioned disaffection with life is one factor. Another factor is that the individual was a doctor, familiar with the properties of laudanum, a tincture of opium. Certainly he would have known that two ounces was more than enough to kill him. Four times over.
Apparently his relatives were not with him in St. Augustine, for the documents refer to heirs being "absent in their native country" of Ireland. Was loneliness a factor? Had he suffered reverses of some sort? Was he terminally ill? I have only transcribed part of the file, so I do not know yet if there is further information.
In the nineteenth and early twentieth centuries, laudanum was available over the counter, and was taken for a variety of ills. Narcotics generally were freely available, even as an ingredient in soft drinks. Coca-Cola is so named because it originally contained cocaine. As the dangers of addiction, accidental and deliberate overdose, inability to function fully, and other dangers (including use as instruments of murder) became known, these substances were brought under control.
In our investigations of family history -- our own or someone else's -- we need to be aware of so many bits of history. Medical history is only one of these. Online sources for medical information include Wikipedia (for a general overview and possibly some sources to check), The Merck Manuals, and Antiquus Morbus. The Merck Manuals provide modern information on such aspects as dosage and side effects of medications, and signs, symptoms, and treatment of diseases. Antiquus Morbus is useful for finding what an archaic term for a particular disease refers to in modern terms.
We genealogists are special historians. Not only do we see the large trends of history which influenced the lives of our ancestors, we see the human factor as well, including one unfortunate doctor in St. Augustine in 1810, who so sadly felt that life was no longer worth living.