This manual attempts to provide simple, adequate and evidence-based information to health care professionals in primary health care especially in low- and middle-income countries to be able to provide pharmacological treatment to persons with mental disorders. The manual contains basic principles of prescribing followed by chapters on medicines used in psychotic disorders; depressive disorders; bipolar disorders; generalized anxiety and sleep disorders; obsessive compulsive disorders and panic attacks; and alcohol and opioid dependence. The annexes provide information on evidence retrieval, assessment and synthesis and the peer view process.