In her new book How to Stay Sane, author and psychotherapist Philippa Perry breaks down what makes (and keeps) us sane. Here are her four keys.

As a psychotherapist I cannot pretend that there is a simple set of instructions that guarantees happiness, or even, sanity. We all come from a distinctive combination of genes, and have had a unique set of relationships and experiences that formed us into our present shape; so when it comes to the question of how is it best to live, there cannot be one answer because one size does not fit all. For example, while some people would benefit from being more open, others need to practise self-containment. And what makes me happy might make you miserable; what I find harmful you might find useful. Specific instructions about how to think, feel and behave thus offer few answers. But there are underlying principles that do apply to all of us and can help us.

When it comes to our brains, all humans could be said to be born prematurely, as many of the neural pathways in our brains are formed after we are born, and in relationship with our earliest caregivers. If they do a good job and manage to soothe us regularly when we are upset, we eventually internalise this process and learn how to manage our own emotions.

We also need our parents to validate our various moods and mental states in a safe way as we grow up; acknowledging when we are hurt, in pain, joyful and every other nuance of emotion. This allows us to develop all parts of our personalities. If some of our moods are punished or ignored, trouble can arise later on in life.

As you learn in relationship with your earliest caregivers how to regulate your emotions, your brain will be making lots of new pathways that are necessary for you to learn to become comfortable with your emotions and manage them for yourself. Your earliest bonds also serve as a blueprint for all subsequent relationships, teaching you to form nourishing, enriching, and mutually beneficial relationships throughout your life. The bulk of these neural connections happen before you are two years old. In other words, much of the wiring up that determines how you respond emotionally and conduct relationships, happened pre-verbally. The logic, reason and language part of your brain develops so slowly that most of the patterns for how you feel are formed before you can reason with yourself and with others. This leads to one of the pitfalls in the way of sanity - our use of reason to justify our automatic responses.

If your relationship with your earliest caregivers was less than ideal, or you experienced trauma so shocking it undid the security established in your infancy, it is possible that later on in life you may find yourself in emotional difficulties. But although it is too late to have a happier childhood, or undo a trauma, that doesn't mean you can't be happier in the future. Your brain is fairly plastic and you can make new neural connections to change that chemistry so that you can improve your self-soothing, self-regulation and how you behave in relationships.

How do you do that? There isn't a foolproof prescription – if you are in a downward spiral you need to interrupt that spiral with medication, or a different set of behaviours, or something else. I'm being vague on purpose; what works for me might not work for you. But there are four underlying structures for positive change. In no particular order, they are:

1. A safe, trusting, reliable relationship that is for your sake. Not necessarily a romantic relationship, but a nurturing one (it could be with a therapist, a teacher or a group). We are formed in relationship – so the easiest way to re-form, is in relationship.

2. Positive stimulation – good stress. Enough to push you to learn new things and practise them, but not so much it tips you over into panic. Good stress enables new brain connections to be made and a plastic brain is what you need for personal development and growth. Examples could be learning to play a musical instrument, or a new language or forging other new habits or honing existing skills. Just as our body atrophies without exercise, so do our cognitive skills without stimulation.

3. We need to continue to improve our self-awareness throughout life so self-observation is essential for sanity. This is an accepting and non-judgmental part of yourself. It acknowledges emotions but gives you space to decide how to act on them. This part listens to and brings together your emotions and your logic. To help, try keeping a journal, or practise meditation, get used to noticing your feelings and thoughts without judgment.

4. It's a good idea to have a look at the stories we live by. Because so much of our self is formed pre-verbally, and because in the western world we have a constant background of alarming news stories, the beliefs that underpin our actions and feelings can be covert. It is important to view your life from fresh angles and to let go of fixed ways of defining yourself. Without thinking finish this sentence: "Most people are ..." The word you inserted if you allowed it to arise from your unconscious uncensored will probably have a significant influence on the course of your life. When we examine the stories we live by, we give ourselves the opportunity to edit the stories that no longer work for us.

These four processes: relationships, stimulation, self awareness and stories can be the basis for a framework for change. In psychotherapy these are the areas that are worked on, they may not be separated in this way, but these are the bases that need to be covered for therapy to work. In my book, How To Stay Sane, I have a deeper look at these four areas and how they can be applied to self-help.

Most self-help books focus primarily on change so we can be 'more' something: more confident, more assertive, more likeable, more courageous, more rich. I hold onto a different principle: The most meaningful changes only occur when become more mindful of who we already are.

PHILIPPA PERRY is a psychotherapist and writer. Her work has appeared in The Guardian, The Observer, Time Out, and Healthy Living magazine. In 2010, she wrote the wry graphic novel Couch Fiction, in which she demystifies the practice of therapy using the form of a case study. Her latest book, How to Stay Sane, is out now from Picador.