It was clearly demonstrated in the two sections on Depression and ADHD that the relation between behaviour and brain function (QEEG or quantative EEG) cannot be considered a causal and clear relationship. From the Depression section it became clear that several sub-types of Depression might exist responding differently to different types of medication. From the ADHD section it might also be hypothesized that several sub-types of ADHD exist. Indeed several publications discuss different EEG subtypes for several disorders, but thereby the main classifier is still the DSM-IV: behaviour based.
Furthermore, several of the sub-types found in Depression have also been found in ADHD. In a study by Suffin & Emory (1995) it was shown that efficacious treatment outcome to various types of medications was best predicted by QEEG (Frontal Theta excess vs. Frontal Alpha excess) and NOT DSM-IV group. The prescribed medication was only based on brain function profiles which could sometimes lead to ADHD patients being prescribed an antidepressant and Deppresive patients prescribed a stimulant. In general efficacy tended to be > 80% on average.
Therefore, it seems more likely there are several EEG Phenotypes bearing some relation to behaviour but not disorder specific. In a recent paper by Johnstone, Gunkelman and Lunt (2005) a very interesting proposal for specific EEG Phenotypes is given, a must-read for anyone interested in QEEG. Note however, that looking at EEG's in this manner is different then traditional Neurological EEG. In QEEG advanced quantative analysis and comparison to a normative database are performed in order to get more sensitive information from the EEG.
Below find a table from their publication summarizing the EEG Phenotypes they proposed. In the menu on the left we have listed some often observed EEG phenotypes and will show you some concrete examples of these, their relation to Neuropsychological and Psychological measures (concurrent evidence) and how well they respond to treatment: Diffuse Slow Activity - Beta Spindles - Low Voltage EEG.
