Lithium is the most widely used and studied medications for bipolar disorders. They also have a role in treating depression and mania, acutely and long term. Once ingested, lithium becomes prevalent in the central nervous system (CNS), and can bind to a number of receptors in order to block norepinephrine production. It can also interact with neurotransmitters in order to cause a release of seratonin. 

Selective serotonin reuptake inhibitors (SSRIs) are commonly used to treat mood disorders. The other choices are used for other types of mental illnesses.

SSRIs (selective serotonin reuptake inhibitors) are commonly prescribed for depressed patients to increase the amount of serotonin in their bodies. Having a greater amount of serotonin is associated with experiencing more positive emotions.

Lithium is typically used to treat the manic symptomology associated with bipolar disorder.

Selective serotonin reuptake inhibitors interfere with serotonin transport in the brain's synapses and can work to elevate mood. SSRIs are used to treat depression, obsessive-compulsive disorder, schizophrenia, bipolar disorder, and post-traumatic stress disorder. Treatment for personality disorders with SSRIs is not successful. 

Benzodiazepines such as Xanax, Klonopin, Ativan, and Valium, act like sedatives, but without their sleep-inducing effect. These medications can be effective in the treatment of panic disorders.

Selective serotonin reuptake inhibitors (SSRIs) such as Zoloft, Paxil, and Luvox, are mood stabilizers and are used to treat depression. Nardil is a monoamine oxidase inhibitor (MAOI) useful in the treatment of post-traumatic stress disorder by reducing nightmares and insomnia. Catapres and Inderal, which are antiadrenergic agents, are also useful in the treatment of post-traumatic stress disorder. Antiadrenergic agents reduce startle reactions. Lithium is a mood stabilizer used to treat bipolar disorder and schizophrenia.

Depressants are drugs that reduce neural activity and slow down bodily functions. Cocaine is a stimulant, which increases neural activity and speeds up bodily functions. All of the other answer choices are depressants. 

Selective serotonin reuptake inhibitors (SSRIs) block the reabsorption of serotonin in the brain to help ease depressive symptoms. Some of the most popular SSRIs are Zoloft (Sertraline) and Prozac (Fluoxetine).

MAO medication inhibits MAOs, which normally inhibit serotonin, dopamine, and norepinephrine, so that these neurotransmitters can increase in concentration.

SSRIs (selective serotonin reuptake inhibitors) are used to treat depression because they block the reuptake of 5-HT serotonin, allowing it to remain in the locus coeruleus (LC) to block anxiety there.