Readers should know that PL will teach an approach to psychopharmacology that is quite different from, even opposite to, what you are usually taught. The most common approach, taught in the most popular psychopharmacology textbook and throughout training programs in the US, is the biological approach. This drug blocks this receptor; that drug blocks that receptor; this drug increases serotonin, the other increases norepinephrine. And this drug increases everything, so it's even more effective!
This kind of biological teaching is not completely false; it is important to know biological mechanisms, which can sometimes correlate with clinical effects. But when used as the primary means to make judgments about how to use drugs, this biological speculation is just that: a neuromythology (as the German psychiatrist/philosopher called similar tendencies a century ago). It has the trapping of science, and it makes clinicians feel like they know what they're doing: but it's pseudoscience - speculation that goes far beyond what we actually know.
The PL approach, in contrast, is clinical. We don't care about the biology of drugs (we do, but not as a matter of primary importance). Our primary interest is not what drugs do to receptors or neurotransmitters in rats, test tubes, or PET scans. We care about what they do for clinical symptoms in living human beings. In other words, in contrast to the psychiatric journals and NIMH grant funding, and opposed to the conventional wisdom of the psychiatric profession today, we put clinical research above biological research.
The primary scientific evidence to use about which drugs to use and how is based on randomized clinical trials in human beings, not biological speculations about clinical effects in psychiatric illnesses in humans based on studies of receptors and neurotransmitter in rats (or even humans for that matter). A drug can enhance every neurotransmitter in the world, but if it is not better than placebo in a RCT, it doesn't work, and you shouldn't prescribe it. A drug can block every receptor that you'd like to block theoretically, but if it has never been tested in a RCT for a psychiatric condition, then you don't know if it really works or not, and you shouldn't pretend otherwise.
So we will teach you clinical psychopharmacology, based on randomized trials and clinical studies as your primary source of evidence, with biological mechanisms as a secondary consideration. This is the reverse of the approach of the most prominent psychopharmacology textbook and current conventional wisdom. The latter approach leads to many speculative judgments about drugs, and their overuse and polypharmacy, causing, in the opinion of PL editors, more harm than good. The PL approach will lead to use of fewer medications, but more effectively and on more solid scientific ground.
Thus, we will privilege and focus on clinical trials rather than biological theories. You will need to learn about how to interpret RCTs, and statistical knowledge will be necessary, and PL will teach you that knowledge. It is more work than simply speculating about the benefits of having more of this or that neurotransmitter. But it is scientifically more sound, and clinically more effective.
We hope you'll find that this philosophy of psychopharmacology is fruitful, and you will join PL in following the old teaching of Hippocrates, who focused on clinical evidence and opposed biological speculations about too much or too little of four humors (which is basically the same as our current biological theories about "chemical imbalance" with neurotransmitters). Ignore theories (of any kind, including biological), and focus on what actually is happening in clinical practice, with randomized trials as your best evidence.