Pramipexole treatment enhances DA and 5-HT neurotransmission and increases tonic activation of post-synaptic D2 and 5-HT1A receptors in the forebrain.370 Apart from PD, Pramipexole can also be prescribed for psychiatric conditions such as treatment-resistant depression and bipolar disorder.371. This evidence concerns the gene HTR1A and major depressive disorder.