Where the making of a will is concerned, the law will be relatively unconcerned if your death was a suicide or not. What counts, in terms of making a will, is that you were of ‘sound mind, memory and understanding’ at the time that you made it.
This means that you must understand what you are doing in making your will. You must have a good general overview of your assets that you intend to give away, you must be mindful to those who may have a ‘moral claim’ to your assets (eg. your blood relations) and, finally, you must be aware of the ramifications of dividing your assets in the way you have done.
If you fulfill these general legal requirements, you will be said to have ‘testamentary capacity’. So even if you then go on to suicide, your will will be relatively safe from contest, at least on the grounds of mental incapacity. If safeguarding your will is important to you there are several further steps that can be taken as extra precautions. These may be particularly important if your will is contested in court and if the ‘other side’ calls hostile psychiatrists as expert witnesses.