Long-term insomnia can be caused by a number of factors, including mental health issues like anxiety disorders, depression, or PTSD. Medical illnesses that are painful or stressful are another common cause. Some neurological disorders, such as Alzheimer’s and Parkinson’s disease, are connected to insomnia. Those with other sleep disorders, such as restless legs syndrome or sleep apnea, have an increased risk of developing insomnia. Finally, medications, alcohol, and drugs may lead to or exacerbate insomnia and there is even a genetic component linked to a higher likelihood of developing long-term insomnia.