Dear Mr Snuggles, The extreme German medical confidentiality laws mean that even after death we cannot see what the many medics he saw, recorded about their consultations and diagnosis. Before the disaster they were afraid to contact the authorities to stop him flying in case they were sued. We have therefore no significant detail about his mental state in the period leading up to Lubitz's actions.
The vast majority of people with depression would not harm others, except by causing psychological distress to friends and family by their suicide.
There is no clear evidence that Lubitz was psychotic as we cannot see his medical records. He did have anxieties about his eye sight which was probably more of a psychosomatic or hypochondriacal nature rather than being psychotic.
Due to German extreme secrecy we are losing an opportunity to understand what went on in Lubitz's mind in the weeks leading up to the crash. The Germans need to reform their confidentiality laws both so that we can understand this disaster and hopefully identify any future Lubitz.