These are among the newer antidepressants, which have been available from 1988. They act on the neurotransmitter serotonin. Some of the trade names in this class include Paxil (Paroxetine), Prozac, Lorien, Nuzak, Lily-Fluoxtine (Fluoxetine), Celexa (Citalopram), Zoloft (Sertraline) and Luvox (Fluvoxamine).

This group of drugs is the most widely prescribed due to the favourable side-effect profile and relative safety if taken in overdose. Different drugs in this class are also registered for treatment of anxiety disorders, panic disorders, post-traumatic stress disorders, obsessive-compulsive disorder and social phobia.

Side effects may be present during the first few weeks of therapy, but usually disappear after a while. These are often diminished by starting medication in low dosages and gradually increasing until a therapeutic dosage is reached.

Common side-effects include:

• nausea - (take after food);
• headache - (improves after a while; start with low dosages) ;
• agitation/anxiety;
• sleep disturbances;
• decreased appetite;
• sexual disturbances.