The difference between ODD and PDA

It is clear that these behaviour profiles could look very similar. You have a child in front of you who refuses point blank to do as they are told and acts violently and aggressively if you try to make them. If your child is also ADHD, which the majority of children diagnosed with ODD are, impulsivity, emotional regulation, executive function and some sensory issues will also be present. ADHDers also have some social difficulties due to their impulsivity and attention struggles. It is also noted that to co-occurrence of ADHD with PDA is much higher than for the general population. You can see how parents feel confused, and frustrated. I was. So let's look at the differences.

For children with ODD, their behaviour is understood to originate from a persistent and pervasive state of negative thinking and emotions, that stems from extremely difficult experiences or a persistent environment of negativity, either at home or at school, this can trigger a negative state of mind as the "norm" for them. For instance, research shows that ADHD children receive considerably more criticism than neurotypical children. The ODD child is triggered by the perceived source of negativity; authority. This leads to emotional fragility, persistent anger and annoyance, low tolerance for people, and frequent confrontations and altercations with people in positions of authority. ODD is a childhood behaviour profile which, if it continues, can become an adult conduct disorder.

For the PDAer, the behaviour is understood to be a difference in wiring and chemistry in the brain that (amongst other things) triggers a threat response when the person is faced with demands. I actually believe that it would be more accurate to describe that the response is triggered when there is any perceived threat to their autonomy, but that is a matter for another day. The key thing is that demands (all kinds) will cause the PDAer to go into fight (aggression and violence), flight (avoidance to extreme degrees) or freeze (shutdown).

A child with ODD will have fairly consistent negative emotions to lesser or greater degrees at a given time. The PDAer is more likely to switch moods inexplicably and experience fleeting emotions where they may suddenly flip, and then are back to being ok reasonably quickly. The PDAer can swear at, scream at and threaten the people they love to avoid a demand, and then when the demand is removed, as long as meltdown hasn't happened, be suddenly calm and affectionate. This is not manipulation but genuine terror occurring and subsiding. The ODD child will remain angry and resentful for longer.

Equally the PDAer is likely to feel full of remorse after a meltdown for the behaviour displayed, as a meltdown in its nature is a total loss of control.

The ODD child is less likely to feel remorse and is more likely to remain in control of their actions, though not always.

So what makes the defiance different? Here is where it is super tricky. All human beings can be defiant and all human beings can be demand avoidant. This means both children can display both behaviours. However this also makes it easy to understand.

​We have all felt like we do not want to do as we are told by the person in front of us because we feel angry inside ourselves, or angry with them, or angry about having to do the task. When we refuse on these grounds, we are being defiant and our refusal is driven by anger. In these cases we outright refuse or we become obviously and outwardly angry.

We have also all felt like we do not want to do something or are unable to do something for other reasons that are not because we are angry or annoyed at being asked. It could be from exhaustion, a lack of motivation or from apprehension at the complexity or length of the task. Ever left an essay to the last minute? This apprehension can sometimes be more extreme and be better characterised as anxiety. Avoiding doings things because the thing causes us anxiety is typical. In some people, including those with mental health difficulties and neurodivergences, certain tasks or activities (like making phone calls, going outdoors, social gatherings or complicated organisational tasks) are anxiety inducing. These people will go to greater lengths to avoid these tasks than others. All of this is considered demand avoidance and it is driven by either a lack of motivation, lack of executive function or by stimulus that causes anxiety.

The reason that PDA is described using the P word is because the avoidance of demand in the PDAer is abnormal or atypical and to an extreme and pervasive degree. The PDAer does not only avoid demands that cause them anxiety. The PDAer's anxiety is actually caused by the presence of demand. The telling, requesting, reminding, begging, or even gently expecting of the PDAer all cause utter panic, even when they expect things of themselves.

I keep struggling to describe the feeling to people but I will give it a go: I am a black belt in Taekwondo. I love it and find classes really help my mental health. I really enjoy it. However, I battle myself every time it is Taekwondo day, arguing in my brain with my PDA. My threat system is telling me that everyone expects me to go, including me, and I need to resist at all costs. I have to fight it with everything I have, because I want to go. If anyone reminds me to get ready, it feels like they just put a brick wall up in front of me, and my brain screams STOP. DANGER. FIGHT. RUN.

As you can see from this description this can be a long and slow internal struggle, which can suddenly become unmanageable. I am an adult so I mostly fight with myself but when pushed I will use all kinds of strategies to avoid demand, including, distraction, procrastination, incapacitating myself, making excuses, and on and on until it’s all too much. For me meltdowns are sobbing for hours or visible panic attacks and sometimes it is more shutdown.