What is the Chemical Difference Between Postpartum Depression (PPD) and Depression?

Major depression and postpartum depression are similar in many ways, but they have different underlying causes. While major depressive disorder can occur at any time, postpartum depression (PPD) develops in connection with pregnancy and delivery. 

Healthcare providers typically diagnose PPD within the first year following childbirth. However, untreated episodes can continue well beyond that timeframe.

How Does Brain Chemistry Affect Major Depression?

Clinical depression affects how people experience emotions and process thoughts, which can adversely affect their everyday routines. Medical research has shown that depressive disorders are linked to complex communication breakdowns among key neurotransmitters, especially serotonin, dopamine and norepinephrine.

Standard antidepressant medications, such as selective serotonin reuptake inhibitors (SSRIs), work by gradually elevating the amounts of these mood-regulating chemicals in the brain. 

What Biological Changes Trigger Postpartum Depression?

While clinical depression is caused primarily by inadequate amounts of specific neurotransmitters, PPD is triggered by a rapid decrease in hormones immediately after childbirth.

The Sudden Drop in Reproductive Hormones

During pregnancy, progesterone levels increase by 10 times, while estradiol levels surge up to 50 times above baseline. Within 48 hours following delivery, these hormone levels fall back to pre-pregnancy numbers. This sharp drop directly impacts mood-regulating neurotransmitters, including serotonin and gamma-aminobutyric acid (GABA).

Thyroid Hormone and Neurosteroids

An abrupt decline in thyroid hormone production following delivery can also mimic or intensify depressive symptoms, leaving new mothers exhausted. Additionally, fluctuations in a neurosteroid called allopregnanolone can play a role in the development of PPD.

What Are the Symptoms of Postpartum Depression vs. General Depression?

Depression and PPD have many emotional and physical warning signs in common, including: 

• Feelings of sadness, emptiness or low mood happen almost every day.
• You feel restless, extremely anxious or overwhelmed by sudden panic.
• You cry much more than usual, often without knowing why.
• You feel completely worn down and exhausted, even after getting rest.
• Your appetite shifts, causing you to eat significantly less or more than normal.
• You struggle to fall asleep, stay asleep or get out of bed.
• Guilt, shame or feeling like a failure can weigh on you.
• You lose interest in favorite hobbies, daily activities and spending time with friends.
• Trouble focusing, remembering details or making simple decisions becomes frustrating.
• You deal with ongoing body aches, headaches or stomach troubles that have no clear reason.
• You have thoughts about hurting yourself or not wanting to wake up.

Alongside these shared signs, postpartum depression brings specific hurdles that come with welcoming a new baby, such as:

• Disrupted sleep and round-the-clock feedings leave you running on empty.
• Thoughts about bad things happening to your baby pop into your head.
• You frequently or constantly doubt your ability to be a good parent.
• Connecting or feeling close to your baby feels unexpectedly hard.
• Nursing challenges or weaning difficulties add physical and emotional stress.
• You feel distant, lonely or resentful toward your partner, family members and friends.
• Adjusting to the huge lifestyle change of parenthood feels overwhelming.

Finding Support and Care for Postpartum Depression

Without treatment, postpartum depression can linger for months or even years, but you don’t have to deal with it alone. Getting support as soon as you notice symptoms makes a big difference for your well-being and helps you build a strong, healthy connection with your little one. 

If you see any of the signs of postpartum depression in yourself or someone you love, reach out for help. Contact your primary care physician, OB-GYN or a mental health professional to talk through helpful next steps. You can find care near you in our provider directory.