In the Vlog, The Autobiography of Jane Eyre, Rochester attributes Bertha's mental illness to post-partum depression when he is speaking to Jane after she finds out about the existence of Bertha. This is a believable diagnosis and represents an accurate modernization of the story in this area. Postpartum depression is very different than what's called "baby blues". The signs and symptoms are more intense and last longer, and may eventually interfere with the woman's ability to care for your baby and handle other daily tasks. Symptoms usually develop within the first few weeks after giving birth, but may begin earlier, even during pregnancy or later, sometimes up to a year after birth. Postpartum depression signs and symptoms identified by the Mayo Clinic andsome of which are  representative of Bertha's behavior may include:

• Depressed mood or severe mood swings
• Excessive crying
• Difficulty bonding with your baby
• Withdrawing from family and friends
• Loss of appetite or eating much more than usual
• Inability to sleep (insomnia) or sleeping too much
• Overwhelming fatigue or loss of energy
• Reduced interest and pleasure in activities you used to enjoy
• Intense irritability and anger
• Fear that you're not a good mother
• Hopelessness
• Feelings of worthlessness, shame, guilt or inadequacy
• Diminished ability to think clearly, concentrate or make decisions
• Restlessness
• Severe anxiety and panic attacks
• Thoughts of harming yourself or your baby
• Recurrent thoughts of death or suicide

https://www.mayoclinic.org/diseases-conditions/postpartum-depression/sym...