Neurotic depression is not caused by infrequent or isolated incidents of smoking cannabis. Rather, neurotic depression can be caused by many inner and social factors (both known and unknown). Perhaps depression was one of the reasons that you tried cannabis. Cannabis creates a false good feeling that appears to help overcome depression... but its effects are only temporarily. In the end, users will still be depressed and can become addicted to cannabis. Depression and addiction create a cycle wherein depression forces you to take more cannabis and without cannabis you become more depressed. I recommend you to stay away from cannabis and to ask expert help from a mental health professional, psychologist, or other trusted counselor.