All therapy practices ultimately face the same type of basic economic conundrum sooner or later. You've only got so much money in your monthly advertising budget to work with, and basically two places to spend it: SEO for therapy practice visibility that gradually accumulates over time or paid marketing that starts giving results immediately once it's turned on.
It all comes down to the correct sequence of actions based on your current stage in growth. Ads can be good for direct visibility but also come at an added costs and skills, where Therapy SEO takes time and has sustained visibility.

If your website has never had a consistent SEO campaign before, that's typically where your first pound should go. Why? Because it's the only channel where traffic you get comes without a per-click cost. When a page ranks for "CBT therapy in Leeds" or "counselling for anxiety," every visitor it generates is free after the initial effort.
SEO is the platform that everything else connects to. Ads work better on quality pages, content written for real search intent provides ad retargeting opportunities. In addition, unlike ads, SEO continues to do its job even if you don't touch it for several weeks, which can be important when you are busy with clients and marketing falls down the priority list.
The downside is time. It takes months before the rankings start turning into enquiries, so Therapy SEO is not going to fill your diary quickly.
Google Ads do exactly the opposite. They elevate you above the natural results right from the start, and that's very valuable especially when you are just starting out, have moved recently, or are venturing into a specialization you are not yet known for.
Search advertising is where you catch people right in the moment when they want help - that is the highest intent traffic there is.
Social advertising works differently. Facebook and Instagram make people aware of your clinic even before they start looking, but both platforms suffer from the same downside once the payment stops, so does the traffic.

In the case of a regular private practice, we would do the following funding:
First foundations (1st-2nd months). Make sure your site is technically ready; your pages contain relevant keywords and Google My Business is set. Without it, both SEO and ads will be losing money for you.
Small controlled paid campaign (2nd-4th months). Conduct a small-scale Google Ads campaign based on exact match keywords to catch active searchers while growing your organic visibility. Social ads could be used later when your search ads are working well enough or if your practice is purely online.
Reinvest into SEO based on evidence. Utilise your keywords gathered from ads to create organic content and reinvest your budget from ads to SEO step by step as your rankings improve since organic traffic is practically free.
The result won't be either SEO or ads forever. You just need a solid Therapy SEO foundation and a small budget of ads that you will scale up or down depending on your diary.