Selective Serotonin Reuptake Inhibitors are a class of drug that are used mainly in the treatment of depression but also effectively address other conditions, such as generalised anxiety disorder, social phobia, bipolar disorder, personality disorders, etc. The terms ‘reuptake’ and ‘selective’ make SSRIs a little less easily understood. Let us take a look at how SSRIs function to be able to understand why this class of psychotropic compound forms a part of effective artillery in treatment of mental conditions.
Reuptake: Messages in our brain are carried by brain cells aka neurons. Each neuron has projections from its outer membrane (sheath) called dendrites. The place/gap where dendrites of one neuron end and the other begins is called a synapse. To pass a message, the dendrites of a neuron release serotonin, a neurotransmitter, into the synapse. This activates the receptors of the next neuron, which receives this message before relaying it on to the next neuron. After serotonin has been released into the synaptic cleft and the post-synaptic neuron has been activated, the pre-synaptic neuron reuptakes or reabsorbs the released serotonin from the synaptic gap through serotonin transporters (SERTs). This is done, as the reuptake serotonin serves as a feedback sensor for the pre-synaptic neuron.
Selective: SSRIs selectively inhibit the reuptake pumps for serotonin only and do not affect or influence other neurotransmitters in the brain, such as dopamine, tyramine, melatonin or norepinephrine, etc. This gives SSRIs its lesser number and lesser intense side effects in comparison with other antidepressants of the tricyclic family.
Depression and some other psychological conditions are believed to be triggered by low serotonin levels in the brain, either because of the low volume serotonin release by neurons or overactive reuptake inhibitors. It may also be caused by the non-activation of the receptor neuron at the synapse on release of serotonin. These are few amongst the complex many reasons for psychological states to occur.