As in other forms of insanity, hereditary predisposition is found in from 25 to 30 per cent. of the cases. Alcoholism, sepsis, and neuroses like hysteria, chorea, and epilepsy, are the predisposing elements. The most common immediate exciting cause during pregnancy is toxemia from faulty metabolism and excretion. Other frequent direct excitants are mental worry from poverty, desertion, seduction, and the like troubles.
Prolongation of the lactation period beyond the usual time for weaning, from the ninth to the twelfth month, is common among ignorant and lazy women. Some women prolong lactation in the erroneous notion that it prevents renewed impregnation. Such lactation is injurious to the child, as a rule. Ploss says hyperlactation is frequent in Spain, and that some Japanese, Chinese, and Armenian women may nurse their children for years, but this practice is undoubtedly injurious, especially among European races. The women get tabes lactea with emaciation, asthenia, anemia, backache, pain in the breasts, neurasthenia, cramps, and blindness. The uterus atrophies in some cases and may be permanently injured. Insanity is not unusual.
The forms of mental disturbance commonest in puerperal insanity are mania with or without delirium, melancholia, and dementia. Dementia is the final stage in the cases that become chronic. Mania is the prevailing type in insanity after labor, and melancholia in insanity during gestation. The melancholy of insanity during gestation is often suicidal, and must always be watched. Religious and erotic symptoms are also observed.
The onset may be very sudden during labor. An outbreak after labor may be suicidal or homicidal. Maniacal puerperal women are dangerous. They have delusions and hallucinations, with very rapid and incessant changes that range from obscenity to prayer. Melancholy in the puerperium is likely to be suicidal.
About 75 per cent. of puerperal insanity cases recover within five or six months. From 2 to 10 per cent. die from sepsis, exhaustion, or intercurrent diseases; the remainder become permanently insane. The nearer the delivery the insanity appears, the better the prognosis. Menzies found that of cases which began during gestation 56.7 per cent. remained insane; of those that began during the puerperium 25 per cent. did not recover; of those that began during lactation 43.5 per cent. remained insane. Melancholia is more favorable than mania in pregnancy, but after labor mania gives the better prognosis. The maniacal patient is more likely to die, but the melancholic is more likely to remain insane. The older the woman, the greater the number of her pregnancies, the more the depression, and the higher the temperature, the worse the prognosis. Alcoholism is an added risk always.