Sometimes Perinatal mood disorders overlap, and it's hard to tell where one ends and the other begins. PTSD is caused by an event in which you feel threatened, violated, and feel as if you could die. By the way our brain has processed the memory of the event, is causes hightened anxiety, hypervigilence, flashbacks, nightmares, etc. Therefore it is an anxiety or stress reaction and it is different from Postpartum Depression (PPD). However, PPD can occur at the same time PTSD...

PPD is a mood disorder caused by an imbalance of neurotransmitters in the brain. First of all, estrogen is the primary female sex hormone produced primarily by the ovaries and the placenta. Results from a study published in the October-December, 2005, issue of Advances in Nursing Science, “indicate that sudden estrogen withdrawal, fluctuating estrogen, and sustained estrogen deficit are correlated with significant mood disturbance.” (Douma, S.L. et. al.) The reason is that estrogen, the primary female sex hormone produced primarily by the ovaries and the placenta, regulates Monoamine oxidase (MAO), an enzyme in the body that breaks down certain substances including the serotonin and norepinephrine, according to a study published in the 1983 issue of Neuroendocrinology, (Luine, V. N. et. al.) Too much MAO activity is thought to be associated with a number of neurological disorders including depression. Monoamine oxidase inhibitors (MAOI’s) are one of the major classes of drugs prescribed for the treatment of depression.

Serotonin is a chemical in the brain believed to play an important role in the regulation of mood, sleep, sexuality, and appetite. Serotonin has been thought to be a part of the biochemistry of depression, anxiety, bipolar disorder and migraines. Norepinephrine is another chemical in the brain that is a stress hormone, and it affects the part of the brain that controls attention and focus. Selective serotonin reuptake inhibitors (SSRI’s) treat depression by increasing the amount of serotonin available in the brain. Selective serotonin-norepinephrine reuptake inhibitors (SNRI’s) treat depression by increasing the amount of serotonin and norepinephrine available in the brain. (Wikipedia)

Higher levels of estrogen decrease the activity of MAO in the brain, therefore increasing the amount of serotonin and norepinephrine available. The more serotonin and norepinephrine in the brain, the better your mood is. Clinical Gynecologic Endocrinology and Infertility, 3rd Edition, states that during pregnancy, estrogen levels increase over 100 times because is it produced by the placenta while the baby is forming. When the placenta is removed at delivery, estrogen levels drop to what they were before pregnancy, by the fifth day postpartum. (Speroff, L. et. al. 1983) So when estrogen levels decrease, MAO activity increases, therefore decreasing the amount of serotonin and norepinephrine available in the brain. The less serotonin and norepinephrine in the brain, the more depressed we are.

According to the DSM IV, one must meet the following criteria in order to be diagnosed with Depression:

A. Five (or more) of the following symptoms have been present during the same 2-week period and represent a change from previous functioning; at least one of the symptoms is either (1) depressed mood or (2) loss of interest or pleasure.

Note: Do note include symptoms that are clearly due to a general medical condition, or mood-incongruent delusions or hallucinations.

1. Depressed mood most of the day, nearly every day, as indicated by either subjective report (e.g., feels sad or empty) or observation made by others (e.g., appears tearful).
   
2. Markedly diminished interest or pleasure in all, or almost all, activities most of the day, nearly every day (as indicated by either subjective account or observation made by others)
   
3. Significant weight loss when not dieting or weight gain (e.g., a change of more than 5% of body weight in a month), or decrease or increase in appetite nearly every day.
   
4. Insomnia or hypersomnia nearly every day
   
5. Psychomotor agitation or retardation nearly every day (observable by others, not merely subjective feelings of restlessness or being slowed down)
   
6. Fatigue or loss of energy nearly every day
   
7. Feelings of worthlessness or excessive or inappropriate guilt (which may be delusional) nearly every day (not merely self-reproach or guilt about being sick)
   
8. Diminished ability to think or concentrate, or indecisiveness, nearly every day (either by subjective account or as observed by others)
   
9. Recurrent thoughts of death (not just fear of dying), recurrent suicidal ideation without a specific plan, or a suicide attempt or a specific plan for committing suicide
   

B. The symptoms do not meet criteria for another condition.

C. The symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.

D. The symptoms are not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication) or a general medical condition (e.g., hypothyroidism).

E. The symptoms are not better accounted for by Bereavement, i.e., after the loss of a loved one, the symptoms persist for longer than 2 months or are characterized by marked functional impairment, morbid preoccupation with worthlessness, suicidal ideation, psychotic symptoms, or psychomotor retardation.

Specify (for current or most recent episode):

• Severity/Psychotic/Remission Specifiers
  
• Chronic
  
• With Catatonic Features
  
• With Atypical Features
  
• With Postpartum Onset

Symptoms usually improve with treatment.

References:

• Estrogen. http://en.wikipedia.org/wiki/Estrogen, 2006.
• Neurotransmitter. http://en.wikipedia.org/wiki/Neurotransmitter, 2006.
• Monoamine oxidase. http://en.wikipedia.org/wiki/Monoamine_oxidase, 2006.
• Serotonin. http://en.wikipedia/wiki/Serotonin, 2006.
• Norepinephrine. http://en.wikipedia/wiki/Norepinephrine, 2006.
• Douma, S.L., Husband, C., O'Donnell, M.E., Barwin, B.N., Woodend, A.K. Estrogen-related mood disorders: reproductive life cycle. Advances in Nursing Science, 2005 Oct-Dec; 28(4):364-75.
• Luine, V.N., Rhodes, J.C. Gonadal hormone regulation of MAO and other enzymes in hypothalamic areas. Neuroendocrinology, 1983; (3): 235-41.
• Speroff, L., Glass, R.H., Kase, N.G.: Clinical Gynecologic Endocrinology and Infertility, 3rd Edition. Baltimore, MD, Williams & Wilkins, 1983.
• O’Hara, M.W., Swain, A.M. Rates and risk of postpartum depression: a meta-analysis. International Review of Psychiatry, 1996; (8):37-54.
• DSM IV
• Bennett, S.S., Indman, P.: Beyond the Blues: A Guide to Understanding and Treating Prenatal and Postpartum Depression. San Hose, CA, Moodswing Press, 2003.