Depression

            Depression and anxiety are amongst the 10 leading causes of disability in the U. population respectively (Lead Discovery). Depressive disorders are characterized by disturbance in emotions that interferes with normal functioning, physical symptoms (fatigue, insomnia), as well as cognitive symptoms (hopelessness). Types of these disorders are major depressive disorder, dysthymic disorder and premenstrual dysphoric disorder. Anxiety disorders are characterized by mild to severe apprehension, tension, and fear due to no clear cause or specific threat. Types of anxiety disorders are panic disorder with or without agoraphobia, posttraumatic stress disorder, obsessive-compulsive disorder, social anxiety disorder and generalized anxiety disorder (Stevens). .
             An inappropriate level of neurotransmitters in the brain is the basic biochemical cause of these disorders. The brain is made of cells (called neurons), which communicate with each other at places called synapses. A synapse is a contact between two neurons. Neurons generate electrical events called action potentials, which cause the release of a chemical messenger from a storage vesicle in the axon terminal. The chemical messenger (called a neurotransmitter) travels across a synapse to bind to a postsynaptic receptor protein. Some neurotransmitter-receptor bindings excite the cell and others inhibit it. There are perhaps 100 or so different neurotransmitter varieties in the brain. Serotonin, Epinephrine, norepinephrine and dopamine are the main neurotransmitters most common with depression and anxiety (Stevens).
             A deficiency of serotonin in the synaptic cleft may be a biochemical basis or predisposing factor for depression or anxiety disorder. Inhibition of reuptake of serotonin, increasing serotonin in the synaptic cleft is associated with restoring normal mood and functioning. The treatment types for depressive and anxiety disorders, on the pharmacotherapy side, can be MAOI's, tricyclics, selective serotonin re-uptake inhibitors (SSRI's), benzodiazapines and atypicals.