Inter-marriage, influenza, tea-drinking and potatoes were all once blamed for mental health issues, our archives reveal.

A 1901 report, The Increase of Lunacy in Ireland, compared census returns from 1851 and 1891, showing “nearly three times as many lunatics both at large, and in asylums, in the latter year”.

Our reporter added: “Since the year 1891 we have had a constant and well-marked increase in the number of ‘registered lunatics’.”

Legally, a “lunatic” was defined to mean any person “found by inquisition idiot, lunatic, or of unsound mind, and incapable of managing himself or his affairs”.

Our correspondent went on to enumerate popular theories for this increase. The resulting 117-year-old listicle, gives an indicator of some of the unenlightened – and surprising – views about mental health at the start of the 20th century.

“The following are the reasons usually assigned for the spread of insanity in Ireland.”

(1) Poverty, and hence poor and innutritious food

“It has long been recognised by the medical profession that in one predisposed to nervous ailments or insanity anything which causes a great lowering of the vitality of the individuals tends to produce these evils, or to aggravate them if once produced. In Ireland the poorer classes are often very badly fed, and have to work very hard, and the combination of these two circumstances so lowers their vitality that they readily become a prey to various forms of neuroses or nervous complaints.”

(2) Heredity

“The children of insane parents are often themselves insane, and also the children of parents who, though not insane, are yet eccentric, or perhaps drunkards or epileptics, often develop insanity. The offsprings of unsound, imperfectly developed, or degenerate parents are liable to show signs of insanity.

“Now, as the emigrant popular of Ireland is very large, and as those who leave the country are for the most part strong and healthy individuals between the ages of 18 to 30 years, it follows that only the weaker or the old and more degenerate are left behind to propagate the race, and hence the greater tendency to all kinds of neuroses and insanity.”

(3) Too Much Inter-marrying

“In districts where families inter-marry to any great extent insanity is surely produced, and this holds good in several districts in Ireland. In the Barony of Forth, for example, near the town of Wexford, the people form a colony as it were of themselves, and rarely mix with outsiders, and inter-marriages have been going on for some considerable time, with the result that insanity is in this district exceedingly common.”

A 1901 report, The Increase of Lunacy in Ireland, compared census returns from 1851 and 1891, showing “nearly three times as many lunatics both at large, and in asylums, in the latter year”

(4) Anxieties and the Cares and Worries of Life

“In the struggle for life which exists nowadays, when we live at such a high pressure, and when education is pushed amongst the poorer classes to such an extreme extent – in many cases making competition for the various appointments, &c., so very keen and severe that it taxes the strengths of the very fittest amongst us – we find a most deleterious effect produced upon highly-strung and nervous individuals, and in this constant strain we find a cause which is responsible for many cases of insanity which are met with.”

(5) Alcohol

“This as a cause of general insanity has been very much over-rated. It is an easy way out of a difficulty sometimes to say that drink has been the cause of a case of insanity. No doubt, the children of drunken parents are often predisposed to insanity, but few cases are directly traceable to drink. It often happens that when a man’s reason is tottering in the balance if he has the opportunity he will take to drink or other forms of vice, but these cannot be said to be the cause of insanity - the insanity is rather the cause of them.”

(6) The Puerperal State (after child-birth)

“This cause of insanity is fortunately a fairly rare one, and where met with is usually accompanied by some other predisposing cause, such as insane heredity, or a lowered and greatly weakened constitution from poor living, too long nursing after previous pregnancies, a too rapid succession of pregnancies, or possibly sepsis (blood poisoning).”

(7) Certain Diseases

“. . . such as gout, syphilis and rheumatism, have been said to predispose to insanity, but their action in this matter is far from being proven, and moreover, we have no evidence of their increase during recent years.

“Influenza, which has certainly been very prevalent during recent years, has been accountable for a few cases of insanity, and may easily act as a predisposing cause by reason of the great weakness and prostration which it so often occasions.”

(8) The Use of Certain Beverages

“Excessive use of tea or of coffee has been said to predispose to insanity, but their action, if any, is but slight and unimportant.”

(9) The Use of Certain Drugs and Smoking

“The use of drugs, such as cocaine, opium, &c., and excessive smoking, from the nicotine contained in tobacco, has been responsible for a certain number of cases of insanity. But in Ireland these causes do no operate largely, and they can hardly be said to be responsible in any way for the recent increase of lunacy in the country.”

(10) The Use of Certain Foods in Excess

“It has been said that the excessive use of certain kinds of food has produced insanity, and especially of too much starch food. Potatoes may be mentioned in this connection, as the basis of the chief meal of the day is in many parts of Ireland ‘the pratie’. This cause may operate by lowering the general condition of the patients, and should therefore really be classed under the above heading of ‘poverty and poor feeding.’ The same can be said of the agricultural depression in Ireland, which has produced much poverty with its attendant train of evils.

“To summarise the whole situation it may be said that the increase of lunacy . . . may be looked for in the increased poverty of the people . . . When the fight for life is less keen than it is at present, and our lot more peaceable, then, and then only, may be hope to marked decrease in the numbers of those who are unfortunately find their way into asylums labelled ‘insane’.”

- This is part of a series looking at the archives of The Irish Times concerning health.

1) Sleeping secrets: undress in the dark

2) Cooking for invalids: wine and champagne

3) Eat fat, no milk: 19 rules of long living

4) Bloody cures for women’s periods

5) Electrical cures to revive sluggish functions

6) Your ‘flatulence’ explain your ‘noises’

7) Curing psoriasis with nude sunbathing

8) Weight-loss: Obesity soap and fat massage

9) Institution Dubliners hoped they'd never enter

10) Cocaine Tooth Powder

11) ‘Sun-ray’ therapy

12) Men’s hair products

13) A history of Irish lunacy