Psychological and social factors, whether or not combined with physio-pathological disorders, may play a decisive role in a person's inability to adapt to shiftwork. Generally speaking, attention is drawn to the feeling of being cut off from the community and of not participating in social life and collective responsibilities. Moreover, when members of the same family have different work schedules it is particularly difficult for them to get together and organize their family life. Because of the need to work during weekends and on holidays, collective leisure activities, family and neighbourly relations and participation in group entertainment also suffer from shiftwork.
In virtually all epidemiological studies, the most frequently observed disorders have to do with the digestive system, frequently combined with sleep anomalies. Altogether, some 25 to 30% of shiftworkers complain of lack of sleep when undergoing clinical tests, either because of difficulty in going to sleep or a tendency to wake up early. In almost 50% of the cases covered by studies of intolerance symptoms connected with shift work, lack of sleep is combined with other pathological disorders. In a survey conducted in France in 1973, of the people surveyed, 30% suffered little inconvenience from shiftwork; 25% encountered some difficulties; 35% encountered more serious problems that had repercussions either on their health or on their family life, usually because the wife also worked and 10% developed serious sleep and health disorders and found it difficult to organize their family and social life with the result that crisis situations arose that seemed to be caused by a physiological disequilibrium rendering adaptation impossible.