Cyclic triazo and diazo sodium channel blockers

A method of treating a disorder comprising administering to a subject in need thereof a compound of general formula (I), or a salt or solvate thereof,

• in which:
• X and Y are each N;
• Z is a single bond or an optionally substituted linking group;
• R1 is hydrogen, or a substituent group, or the Y nitrogen is unsubstituted;
• R2 is amino or a substituent group;
• N* is amino when R1 is hydrogen or ═NH when R1 is a substituent group;
• or
• N* is a group NRaRb where Ra and Rb are independently H or an alkyl group;
• or
• N* is an optionally substituted piperazinyl ring;
• and
• A is a sulphur containing heterocycle substituted with halogen, alkyl or alkoxy;
• wherein the disorder is a neurodegenerative disorder, motor neurone disease, Alzheimer's disease, Parkinson's disease, bipolar disorder, a mood disorder, an anxiety disorder, a cognitive disorder, or schizophrenia.