In short, it depends! This question cannot be answered with a simple "yes" or "no." The importance, value, or relevance of the content, otherwise known as form, of our thoughts, depends primarily on their function. Let's discuss the terms form and function for a moment. When we speak of a thought's form, we are referring to the content of our thoughts; the specific words or images that appear in our mind. A thought's form can be considered along a negative-positive spectrum, although I'd argue this isn't nearly as important as function. Let's take a negative thought-form such as "I'm a piece of shit." Many people would consider a thought like this negative or bad, and likely to do more harm than good. I could also have a positive form of thought such as "I'm a kind person." Most people would consider this to be a positive form of thought as kindness is generally a well-regarded character trait. The negative-positive thought-form spectrum is rather arbitrary and is used primarily just to help convey the concepts in this article. After all, it takes a judgment to determine the degree of negativity or positivity a thought has. If we treated a thought-as-a-thought then we wouldn't get caught up in the judgment of how positive or negative the thought's content is. Anyhow, I digress. Now here is where things begin to get interesting. When we speak of a thought's function, we are referring to the effect it has on us. For example, I have the thought "I'm a piece of shit." For many people, this thought will have a negative function or negative effect on us. So when I think "I'm a piece of shit" I may then feel bad about myself and engage in behaviors that do not benefit me, and may actually harm myself or others. One reason for this is that the mind seeks coherence, in other words, the mind likes to be able to make sense of things. The thought "I'm a piece of shit" fits perfectly with self-damaging behavior and therefore becomes coherent, and the mind craves this, for better or for worse. Therefore, I may isolate, use drugs, lash out, overeat, self-criticize et cetera, so that the behavior fits my narrative and the narrative fits my behavior. We, humans, tend to struggle with narratives that don't make sense. This is one reason why we can easily get caught in mental rumination trying to figure out what a particular thought means or why we had it; our mind wants it to make sense!
If I have the thought "I'm a kind person" I may then feel good about myself and feel motivated to do something kind for myself or others. This equates to a positive function because the thought becomes helpful to me and others; it moves my life in a direction I'd like it to go - granted that I value kindness. Now here's where things get really wild. A thought's content, or form, is not necessarily indicative of its function. For example, take the thought "I'm a piece of shit" again. This negative thought can actually have a positive function. For a person who has gathered a solid therapeutic toolkit, this thought can serve as a reminder to practice self-compassion and compassion for others. Now, a negative thought has become helpful! In contrast, take the thought "I'm a kind person." This thought can actually have a negative function for someone. For example, when I think "I'm a kind person" I may instantly feel bad because it results in me thinking "I'm too kind and people take advantage of me because of it." Or I may think of an area in my life I feel I'm not succeeding in, say business or romance, and attribute the lack of success to "being too kind." Now a positive thought resulted in a negative effect. There is a great deal of science as to why this is the case. (If you'd like to learn more about this, I'd suggest reading up on the ACBS website). So we've lightly covered the form (content) and function (effect) of thoughts. Now let's talk about thought relevance, specifically within the context of OCD.
There is some debate as to whether the content of our intrusive thoughts is relevant or not. Some will say the content is not relevant and that it's all the same regardless of details. Others will say that there is value in the content. I believe both to be true. The first thing we can do is determine whether our thoughts are helpful or not. In other words, do our thoughts have a positive function? Do they serve us? Do they have a positive effect on us?. If they are not helpful we can ask ourselves if we can either let them go or make them helpful (transform their function to a helpful one). We can even argue that "letting a thought go" could be us making a thought helpful as it provided an opportunity to be mindful and practice our mindfulness skills. (If you'd like to learn specific techniques on transforming a thought's function, I suggest reading The Happiness Trap by Russ Harris). If we deem a thought not to be helpful and are unable to let it go, then we need to transform its function if we are to move our lives in a positive direction. If I have the negative thought and mental image of suffocating a baby and can't get it out of my head, I can allow that negative thought to be a cue to practice exposure and response prevention that my therapist and I created. Or, I could go into my core fear, and in doing so, practice ERP along with moving toward acceptance of uncertainty. In this case, I have taken a negative thought and used it to my benefit. This will most likely require practice. To pose this idea another way, take the example of two basketball teams that just lost a game. One team takes the loss as a sure sign of how crappy of a team they are and how they are going to have a bad season (not helpful). Another team views the loss as an opportunity to have their weaknesses revealed to them so that they can address them directly, make adjustments, and implement them during the next game. This is a simple concept but can be a difficult practice as more thoughts, feelings, and self/other-narratives tend to get in the way. We can decide how relevant we want our thoughts to be by choosing or determining what is helpful and what isn't. I like to ask myself, Is this thought helpful or useful to me? If yes, great. If not, can I make it helpful/useful or let it go? This will grow exhausting if we do this with every single uncomfortable thought we have, so it may be helpful to opt to use it for thoughts that are very sticky and highly troublesome. The rest of the time, perhaps imploring a more mindful approach and trying to look at thoughts rather than from thoughts may be more useful. This is similar to watching cars drive down the road versus getting in one of the cars and traveling down the road with it. Remember, this is a practice. It takes awareness and effort. It's essentially an exercise in learning to choose our attitude in life.