There are some common misunderstandings about psychiatric medications. Some of these are even held by psychiatrists. One commonly echoed refrain in medicine, and specifically in psychiatry, is “some medicine is better than no medicine”. This is whimsically fantastic thinking as well as patently ignorant of pharmacology. 

All medications have a time that the medication requires to reach a steady state in a person’s body. A steady state is calculated as five times the half-life of a drug (or how long it takes for the body to metabolize one-half of the amount of medication in the body). This is dependent upon factors of the medication as well as the patient’s body.  A steady state can only reliably be reached with regular dosing. The vast majority of psychiatric medications require regular dosing and are ineffective when taken in consistently. That means a once a day medication needs to be taken every day for a set number of days to reach a steady state. Certainly taking a medication irregularly will result in a level of medication in the body, however, it will not be consistent and not qualify for a ‘steady state’. 

Why does this matter anyway? 

Well, studies of psychiatric medications are highly controlled and patients are typically administered medication to ensure the medication is being taken regularly. That means that the study is an “ideal” and not reflective of actual patient behavior. Even in these highly controlled studies, psychiatric medications have a pretty limited efficacy. Consider antidepressant medications as an example. Repeated studies have shown that 66% of patients taking an antidepressant have their depression respond. Response is defined as a 50% reduction in depression symptoms. The key here is that the patient is still having depression symptoms and meets criteria for Major Depressive Disorder but there symptoms score is 50% less than without medication. That is certainly an improvement, but they are indeed still significantly depressed. Of the patients who respond to an antidepressant, half of those will see remission of their depression. Remission means that a patient no longer meets the criteria of Major Depressive Disorder. This is the goal; they are no longer significantly depressed. Looking at the numbers, that means 50% of the original 66% responders, or 33% of all patients taking an antidepressant for Major Depressive Disorder will see their depression remit. That means that the overwhelming majority of patients, 66%, will see only partial improvement or NO improvement in their depression. This data comes from well-controlled studies where patients are ensured to take the medication regularly. 

Now let’s go back to that refrain, “some medicine is better than no medicine”. If the best studies only show one in three patients taking an antidepressant will no longer be depressed then how many will see their depression remit when they are not taking their medication regularly, or only taking “some medicine”? The answer is unknown as there are no studies to support this refrain.

So in the end, to see a real benefit of an antidepressant, in Major Depressive Disorder, a patient needs to take the medication daily as prescribed for the indicated duration (typically four to six weeks). Anything less than that that leads to unclear benefit. This leads one to ask the following question: If it is not beneficial, then is it harmful? Possibly, as increasing a dose of an irregularly taken medication (possibly from presumed lack of efficacy at the current dose), can lead to high variability in drug concentration in a patient’s body, which may result in mild to severe side effects. 

The take home point is:  most psychiatric medication needs to be taken regularly to see a possible benefit or it is not likely worth continuing at all. And, unfortunately, there is no evidence in psychiatry to support the optimistic refrain, “some medicine is better than no medicine.”