Although cocaine is in the class of CNS stimulant drugs, frequently using it in large amounts can lead to feelings of depression. There are several different ways a person may experience depression resulting from their use of cocaine.
People who regularly use cocaine find they experience feelings of stimulation, euphoria, hyperactivity, and other effects from the stimulant effects of the drug. However, after they discontinue its use, they often find they experience a crash that consists of feelings of apathy, lack of motivation, fatigue, lethargy, increased appetite, and depressive symptoms. This cycle of ups and downs occurs most often in individuals who use large amounts of cocaine or use it regularly.
Chronic cocaine use can lead to a person having difficulty experiencing pleasure because of the changes in neuroanatomy resulting from repeated cocaine use.
Excessive use of cocaine can result in the development of physical dependence (withdrawal). One of the symptoms of withdrawal from stimulants is an alteration in mood that can include feelings of depression.
People who buy cocaine on the street may not be getting pure cocaine. They may be getting cocaine laced with other substances that have the potential to produce feelings of depression.
Cocaine affects numerous neurotransmitters, particularly dopamine, norepinephrine, and serotonin. When these neurotransmitters are activated, there is the perception of reinforcement or reward. Depletion of these neurotransmitters is believed to be associated with many effects, particularly depression. These neurotransmitters are released in massive amounts when people use cocaine, and cocaine blocks their reuptake, leaving them in the space between neurons where they can reattach to the receptor sites. The high from cocaine is extremely short-lived, and abusers of the drug will often go through episodes where they binge on cocaine to maintain the feeling of euphoria. This activity leads to a cycle of massive neurotransmitter release followed by significant decreases in their availability once a person stops using cocaine. This cycle accounts for the crash, leads to permanent changes in the neural pathways of the brain, and results in withdrawal symptoms in those who have developed a cocaine dependence. Over time, this can result in permanent changes in the brain that result in difficulty experiencing pleasure from events that would normally produce it. Chronic feelings of apathy or depression are more likely.