calebprime asks
When is psychiatry effective?
the quick and dirty answer is, "Pyschiatry is effective when it works." There are published studies on the uses of all psychiatric medications. I am not aware of any where:
a)100% of the experimental subjects responded favorably to the medication (i.e. practically or clinically significant symptom reduction),
b)100% of the control subjects didn't respond favorably to the placebo
c)100% of the control subjects were negative side-effect free.
What can be concluded from these studies is this:
-Subjects receiving the medication experienced greater improvement than those not receiving the medication and/or receiving a placebo control. The difference between the medication group and the control group would only be expected to occur 5 times out of 100 (for p=.05) if there were no effect of the medication.
This is a long way from saying that SSRIs always cure depression. Often, the subjects in experiments are not representative of the general population of individuals who may be prescribed the drugs. For example, if the drug being studied is meant to treat psychosis, the experimental protocol may rule out as subjects anybody who has comorbid diagnoses of depression, PTSD, or anxiety. The clinician prescribing the medication in the "real world" clinic, may not subscribe to those rule-outs.
Differential diagnosis of psychiatric disorders can be extremely difficult, and somewhat misleading, if not misunderstood. The Diagnostic and Statistical Manual of Mental Disorder, fourth edition (DSM-IV) is the most commonly used diagnostic system by psychiatrist. Most of your "common" psychiatric disorders (e.g. major depression, autism, bipolar disorder) have polythetic criteria- That is, there are several different collections of symptoms that can receive the same diagnostic label. For example, part of the diagnostic criteria for major depression include the individual demonstrating 5 or more of the following symptoms (simplified for presentation here)
1. depressed mood
2. diminished interest or pleasure in activities
3.more than a 5% change in body weight (gain or loss) or decrease in apetite
4. insomnia or hypersomnia
5. psychomotor agitation or retardation
6. fatigue or loss of energy
7. feelings of worthlessness or guilt
8. diminished ability to think or concentrate, or indecisiveness
9. recurrent thoughts of death, suicidal ideas, or suicide attempts
Within these criteria, a person presenting with a 10% weight gain, who couldn't sleep, was physically agitated, felt worthless, and attempted suicide could receive the same diagnosis as someone with a decreased apetite, who slept all day long, felt guilty, was indecisive, and though about death but had no plan to kill themself. It is not a stretch to think that these two individuals may have different responses to the same medication. For insurance purpose, these diagnosis may have to be given after the first appointment, which may only consist of a 50 minute interview. Not a great system.
Diagnosing autism can be very tricky, and diagnosed individuals can display highly disparate behaviors and symptoms. To illustrate, in the first criteria for Autistic Disorder listed in DSM-IV:
"A total of six (or more) items from (1), (2), and (3), with at least two from (1), and one each from (2) and (3)."
Now that's confusing! In case you're wondering, the "(1), (2), and (3)" refer to 3 separate list of four symptoms each, consisting of impairment in social interaction, impairment in communication, and differing degrees of repetitive behaviors, interests, and/or activities. Speaking from experience, this can get real confusing for the clinician, parent, and individual with autism.
While a diagnostic systems is invaluable for assuring that researchers, clincians, and patients are, in general, referring to similar things when they give a diagnosis, the psychiatric disorders should not be looked upon as a being "natural categories." Thus the need for trial and error with medications, as well as other interventions.