TriCyclic Antidepressants

Discontinuation of Tricyclic Antidepressants
these medications work, basically, by increasing the levels of certain neurotransmitters, special chemicals in the brain. It is thought that depression is the result of having too little of these neurotransmitters.
Discontinuing these medications can result in withdrawal symptoms, including includes flu-like symptoms (nausea, vomiting, fatigue), sleep disturbances, movement disorders, increases or decreases in energy level, and irregular heart beat.

Mono-Amine Oxidase Inhibitors

Discontinuation of MAO Inhibitors
MAO Inhibitors basically work by increasing the effects of the neurotransmitters that you do have. They interfere with the enzymes that break down neurotransmitters while they are working.
Discontinuing these medications can result in withdrawal symptoms similar to those noted above. However, more severe symptoms have been reported, including agitation, thought disorganization, aggression, and delirium.

Selective Seritonin Reuptake Inhibitors

Discontinuation of SSRI
these medications basically increase the length of time the neurotransmitters have to produce an effect.
Discontinuing these medications can result in withdrawal symptoms like disequilibrium (dizziness and lightheadedness), flu-like symptoms (nausea, vomiting, fatigue), sleep disturbances, movement disorders, headaches, irritability, slowed thinking, and a return of mild depression.

Such symptoms typically occur within 24 to 72 hours after discontinuing the drug, and are more likely to occur if client abruptly stops the medication. They typically go away very quickly if the medication is begun again. Symptoms tend to remit after two to three weeks.

These symptoms are more severe in many ways because the drug effects more than one area of the brain, and more than one kind of neurotransmitter. The longer you take the drug, the more your brain chemistry becomes used to the effect of the drug. When it is abruptly discontinued after two or more months of use, it can be even more difficult for the brain to readjust without it. As a result, removal of the drug from the system produces more serious side effects.

Further, some SSRI drugs are "washed out" of the body fairly quickly, making the effects of withdrawal occur more quickly. Serzone and Effexor are removed fairly quickly (half of the drug is removed from your system in 2 to 7 hours), while Zoloft, and Paxil, as well as Prozac, take much longer (half is removed in 20 to 25 hours, while for Prozac half is removed in 48 to 72 hours). The manufacturers report that missing a single dose of Effexor can result in such symptoms.

offering education about discontinuation
reinforcing the importance of regular compliance with medication
educating about the impact of alcohol and street drugs on the effects of medication
suggesting ways to relieve or cope with side effects of medications (such as sucking sugar-free candy to relieve dry mouth)
fostering appropriate expectations regarding the effectiveness of medication
addressing cognitive beliefs that may interfere with medication compliance
working with fears of addiction
and noting the need to maintain the medication even after the immediate symptoms of depression have lifted.