Antidepressants: pharmacological profile and clinical consequences.

Three neurotransmitter systems are implicated in the biological basis of depression: the serotonergic system is thought to be a major component in the development of depression and in the efficacy of antidepressant drugs, while the noradrenergic and dopaminergic systems play lesser roles, but are important in the development of antidepressant side-effects. Selective serotonin re-uptake inhibitors (SSRIs) are still the drug treatments of choice in major depressive disorder, but each has a subtly different pharmacological profile, which has implications for pharmacodynamic actions and clinical efficacy and side-effect profiles. Although the precise mechanisms responsible for specific depressive symptoms are not yet well defined, evidence is emerging that some SSRIs may be more effective in combating certain symptoms than others. Fluoxetine appears to be particularly effective in overcoming symptoms of fatigue and low energy, whereas paroxetine or sertraline may be more appropriately used for depressed patients experiencing anxiety. A growing understanding of molecular mechanisms in depression and the unique clinical consequences of each pharmacological agent brings us one step closer to being able to individualize antidepressant treatment on the basis of core presenting symptoms and the needs of the individual patient. ( Int J Psych Clin Pract 2001; 5 (Suppl 1): S19-S28).