Major depressive disorder, also known as clinical depression, is characterized by a persistent low mood and loss of interest over at least two weeks. The exact causes are unknown but may involve genetic, biological, environmental, and psychological factors like stress, childhood trauma, and substance abuse. The pathophysiology of depression involves deficiencies in neurotransmitters like serotonin, norepinephrine, and dopamine according to the monoamine hypothesis. The neurotrophic hypothesis also links low levels of brain-derived neurotrophic factor to loss of neurons and brain atrophy.

1. Spurthi B.S
Doctor of pharmacy (Pharm D)
Mallige college of pharmacy

2. Depression:
Major Depressive disorder/ Clinical Depression
Depression is
characterized
a mood disorder
by persistently low
mood and a feeling of sadness and
loss of interest.
It is a persistent problem, not a
passing one, To be diagnosed with
depression, the symptoms must be
present for at least two weeks
It can affect person’s thoughts,
behaviour, feelings and sense of
wellbeing

3. Symptoms

4. Causes & Risk factors
Exact cause is unknown, variety of factors
may be involved
Genetic Factors: heritable, first degree
relatives are more likely to develop
depression.
Biological factors: reduced level of
neurotransmitters, hormonal imbalance
Environmental Factors: Stress, peer
pressure
Psychological –social factors: Childhood
trauma, Divorce, death of parents, work
issues, financial problems etc., Abuse of
alcohol, amphetamines, and other
recreational drugs, prescription drugs
like corticosteroids,

5. Pathophysiology
1) Monoamine
Hypothesis:
depression is
related to a
deficiency in the
amount or
function of
cortical and
limbic
serotonin (5-
HT),
norepinephrine
(NE), and
dopamine
(DA).

6. Patho-physiology
2) Neurotrophic hypothesis:
Brain Derived growth factor (BNDF)
promotes the growth and
development of immature neurons
including mono-aminergic neurons,
enhances the survival and function
of adult neurons.
Low BNDF level may be
responsible for loss of mono-
aminergic neurons and loss of
function or atrophy of hippocampus
and other brain areas.
Hippocampus lose its ability to
inhibit CRF release by
hypothalamus leading to increased
release of glucocorticoids.