Mechanism of Action of Antidepressants

The main benefits of SSRI antidepressants are believed to involve a chemical in the brain called serotonin. Serotonin is one of the neurotransmitter chemicals important in communication between nerve cells. When a nerve cell is activated, a neurotransmitter is released from the nerve cell ending or terminal.

Mixed Bipolar States

In these common but underrecognized bipolar states, both manic symptoms and a full syndrome of depression are present at the same time. In clinical practice, pure bipolar depressive states and pure manic states are likely less common than mixed states, where significant elements of both states are present simultaneously.

Bipolar Mania and Hypomania

These affective states are characterized by abnormal and sustained elevations in sense of well-being, mood, speech, energy, sense of self-importance and similar symptoms. Individuals with mania or hypomania often have less need for sleep and typically engage excessively in productive or pleasure-seeking behaviors.


Dysthymic disorder is a long-lasting type of depression not symptomatically severe enough to warrant a diagnosis of major depression. People with dysthymia may have complaints lasting 6 months or longer (typically many years) of, for example, low mood, irritability, anxiety and sleep difficulties.


Mood disturbances in depression lead us to feel persistently and pervasively low or unable to experience joy or pleasure. When depressed, we may be pessimistic and tend to view the “glass half empty” rather than half-full. We may be so devoid of hope that we see no reason to go on living, our future (and past) colored in a negative light as far as the eye can see.


Euthymia describes a normal mood or emotional state. Our moods are normally tied appropriately to life events and developments. A job promotion, for example, may lead to a “good mood” of happiness and pride in our work, which is entirely appropriate. Also appropriate to that event may be some measure of anxiety, associated , for example, with the prospect of meeting increased job demands or responsibilities.