Dual diagnosis technically means that the patient has two independent, i.e. a primary psych and a substance misuse diagnoses. Which implies that a substance induced diagnosis has been ruled out. Easier said than done.
Case scenario: Patient reports a long history of polysubstance abuse and an equally long history of major symptoms (e.g., psychotic sxs, affective sxs, severe anxiety etc.)
How do you tease out what came first and what causes what? Ask:
1. Is there any history of sobriety?
‘No”. Then, you should assume that’s likely substance induced until proven otherwise (SIUPO).
“Yes”, then ask:
2. What’s the longest time that you’ve been sober?
If longest sobriety is less than a month, again likely SIUPO.
“More than a month”, ask:
3. During that time did you continue to have sxs?
“No”, SIUPO for sure.
“Yes”. Ask: What sort of sxs, etc.?
You see how the balance starts tilting towards dual diagnosis.
Most trainees do at least a fair job in gathering a long list of past and present symptoms and signs of psychiatric and other medical syndromes.
Most trainees also almost always forget to ask this ONE question:
“And how does this affect you?” Where “this” can be depression, anxiety, you fill in the blanks…
What do you get for this one question?
1. Improvement of rapport. As this question is not only a data gathering tool but also shows being concerned and caring about the patient’s experience.
2. A preliminary estimate of the patient’s insight.
“It affects me in a good way. I kind of like it actually.” A manic response.
“Well, it affects me all right. I would like to have them stop following me.” A psychotic response.
“It drives me nuts. I would like to stop it.” An ego-dystonic response of an OCD patient.
3. When the level of insight is good: An estimate of the level of dysfunction.
“I can still work but I really feel like I am dragging my feet every day.” For a depressed patient this is probably more than mild but less than severe depression.
“It’s more of a nuisance. I am noticing it, maybe my wife, but no one else”. For a patient complaining of short term memory loss this is probably more than just plain age related memory loss, but less than full blown Alzheimer’s Dementia. Mild cognitive impairment is likely.
1. Independent psychotic symptoms
2. Historical and quantitative predominance of affective symptoms: e.g. “for most of my life I’ve been depressed/hyper”; “yes, I do hear voices but my major problem is not the voices but my depression. That’s what always gets me hospitalized”.
3. Rapid decompensations and rapid response to meds. Schizophrenia tends to be fairly chronic. Even when it presents with more of an episodic course it is still typically slow to take off and then get under control.