While parsing the negative consequences of being alone, it’s important to distinguish between voluntary temporary solitude—like choosing to stay home instead of going to a party—and perceived social isolation, i.e., loneliness. When you choose to be alone, it can be refreshing and calming.
Being unwillingly alone all the time, however, can lead to loneliness, which can negatively impact both physical and mental health. Persistent loneliness can lead to depression or exacerbate extant depressive tendencies, and has been linked to some personality disorders and psychoses.
Loneliness can also impair a person’s cognitive functioning and executive control, eventually leading to a heightened risk of developing Alzheimer’s or other forms of dementia, particularly for older people. Furthermore, being alone can exacerbate terminal illnesses, such as some forms of cancer, potentially shortening lifespan.
Being alone all the time is especially risky for older people. Those who are at higher risk of physical injury may find themselves injured, and have trouble getting help.
Ultimately, those who are in good health and enjoy spending time alone shouldn’t worry that it affects their wellbeing. If you wish to be more social and combat feelings of loneliness, however, connecting with a licensed professional can help give you the tools to do so.