ADHD SOA is where, normally, a group of architects continually shift their mind about what "good" looks like from an SOA perspective.
This is all about continually "refreshing" the technology stack. On the technical side it means that rather than focusing on getting things into operations and industrialising their approach the architects instead concentrate on the upfront elements, especially the first few weeks of requirements and development and look for ways to continually shave fractions of effort or add additional features.
Both of these result in lots of unneeded work and an increase in the complexity of the IT estate under management, they slow down progression while generating activity.
The cause tends to be a focus on design and development time optimisations. Unlike the Shiny Nickel pattern which is always about the latest buzz the drive here is always to be different to the last project phrases like "we should try X out" ring around. The most common issue here however is a lack of measures, various different pieces are tried and compared based on personal preference and then combined together on the next project "lets try X with Y but not Z this time". A lot of this comes from vendor product upgrades, after all if you've paid for it then you should use the new features. This isn't driven by industry buzz-words but just pulled along by availability of options and a desire to try new things, often you will end up with bizarre cases where people are pushing using very old technologies along with the latest versions because "we know this worked in 2002" or similar justifications.
The basic cause here is a lack of focus on industrialisation of the delivery process, a lack of measures to demonstrate impact or improvement and a complete disregard for the testing, deployment and operations part of SOA.
So how to fix it? Well first off make people really care about operations. Give the architects a target for operations. If the cost of operations doesn't go down then they aren't meeting their goals. Next up get some proper measures on how long it takes to get new people up to speed on a project and how much of the project is automated. Set the architects the task of improving these metrics. The ADHD approach tends to result in an increase in the time it takes to onboard people as its always new to everyone.