5.7. Families are sensitive to strains induced by social and economic changes. It is essential to grant particular assistance to families in difficult life situations. Conditions have worsened for many families in recent years, owing to lack of gainful employment and measures taken by Governments seeking to balance their budget by reducing social expenditures. There are increasing numbers of vulnerable families, including single-parent families headed by women, poor families with elderly members or those with disabilities, refugee and displaced families, and families with members affected by AIDS or other terminal diseases, substance dependence, child abuse and domestic violence. Increased labour migrations and refugee movements are an additional source of family tension and disintegration and are contributing to increased responsibilities for women. In many urban environments, millions of children and youths are left to their own devices as family ties break down, and hence are increasingly exposed to risks such as dropping out of school, labour exploitation, sexual exploitation, unwanted pregnancies and sexually transmitted diseases.