Yes, they can be held responsible, though the way they are held responsible can vary. If they were not in control of their actions and did not contibute to not being in control (if a condition can be controlled by medication, if someone fails to take their medicine, they can be held liable for having contributed or caused their loss of control, similar to how people are liable for their actions after voluntarily drinking or taking drugs), they may potentially be committed for treatment or otherwise required to undergo some form of treatment. If they were held to be still be in control at the time of the act, they could face the same criminal penalties as anyone else.